Technology Against Terrorism: The

Federal Effort

July 1991

OTA-ISC-487

NTIS order #PB91-219998

GPO stock #052-003-01246-4
Recommended Citation:

U.S. Congress, Office of Technology Assessment, Technology Against Terrorism: The

Federal Effort, OTA-ISC-481 (Washington, DC: U.S. Government Printing Office, July

1991).

For sale by the Superintendent of Documents

U.S. Government Printing Office, Washington, DC 20402-9325

(order form can be found in the back of this report)
Foreword

The United States has been a prime target of international terrorism for at least two

decades. In the 1980s, several terrorist attacks had a particularly powerful effect in mobilizing

public opinion and government action. These were the bombings of the U.S. Embassy and of

the U.S. Marine Barracks in Beirut in 1983, and the destruction of Pan American Flight 103

over Lockerbie, Scotland in 1989. The Federal Government reacted in both cases by devoting

more attention and resources to developing strategies and tools to defend U.S. lives and

interests against such outrages. Unless underlying causes are eliminated, terrorist attacks will

continue. Since they may change in type and scope, the United States must be prepared to deal

with a wide range of eventualities. The widespread availability of sophisticated weapons

makes the challenge of counterterrorism all the more difficult.

In 1989, the Senate Committee on Governmental Affairs; the Senate Subcommittee on

Terrorism, Narcotics, and International Operations of the Senate Committee on Foreign

Relations; and the Senate Committee on Commerce, Science, and Transportation, together

with its Subcommittee on Aviation, requested the Office of Technology Assessment to

investigate the status of research on technological means to protect ourselves against terrorist

threats. A later endorsement of the study was received from the Senate Select Committee on

Intelligence.

This report is the first of two in response to these requests. A classified version was

transmitted to Congress on September 24, 1990, and an unclassified summary was released

to the public separately on February 26, 1991. It deals with the Federal research and

development effort in countering terrorism, and with the state of attempts to use technology

to aid in detecting and preventing attempts to introduce explosives aboard aircraft. A review

of the relevant R&D programs in many agencies is provided. The second report of this study

will be released in late summer 1991.

The help and cooperation of many scientists and officials from the Departments of

Defense, Energy, Justice, State, Transportation, and Treasury, and the Intelligence Community are gratefully acknowledged.

~z? e’ia#ALsl- >

U

JOHN H. GIBBONS Director

. . . Ill
Peter F. Bahnsen

Executive Vice President

MLI International, Ltd.

The Use of Technology in Countering Terrorism

Advisory Panel

Marvin Goldberger, Chair

Director, Institute for Advanced Study

Princeton, New Jersey

Terry Bearce

Program Manager on Low Intensity

Conflict

Los Alamos National Laboratory

Homer Boynton

Managing Director for Security

American Airlines

L. Paul Bremer

Managing Director

Kissinger Associates

Chris Chicles

C.H. Chicles & Associates

Arthur Donahue

President

Softworld Marketing, Inc.

Lee Grodzins

Department of Physics

Massachusetts Institute of Technology

Chris Hatcher

Department of Psychiatry

University of California, San Francisco

Carolyn Imamura

Pacific Basin Development Council

Wilfred A. Jackson

Airport Operators Council International

Jim Jacobs

Director, Nuclear Security Systems

Sandia National Laboratory

Brian Jenkins

Managing Director

Kroll Associates

Michael K. Johns

President

Johns & Bhatia

Engineering Consultants, Ltd.

Donald Kerr

President

EG&G, Inc.

Joseph Krofcheck

President

Yarrow Associates

Robert Kupperman

Senior Advisor

Center for Strategic and International Studies

Richard Porter

Aerospace Services International, Inc.

Billie H. Vincent

Aerospace Services International, Inc.

Stanley Wiener

Professor of Internal Medicine

University of Illinois, Chicago

Joshua Lederberg (ex officio)

Rockefeller University

Vice chairman,

Technology Assessment Advisory Council

NOTE: OTAappreciates and is grateful for the valuable assistance andthoughtfid critiques provided by the advisory panel members.

The panel does not, however, necessarily approve, disapprove, or endorse this report. OTA assumes full responsibility for the

report and the accuracy of its contents.
The Use of Technology in Countering Terrorism

OTA Project Staff

Lionel S. Johns, Assistant Director, OTA

Energy, Materials, and International Security Division

Alan Shaw, International Security and Commerce Program Manager

Anthony Fainberg, Project Director

Michael B. Callaham

Kevin Dopartl

Deborah L. Kyle2

Russell L. Maxwe113

Edith Page4

Peter H. Rose5

Administrative Staff

Jackie Boykin

Louise Staley

Donna Reynolds

Contractor

Yonah Alexander

Ion ~s~i=ent ~om OTA*S Science, Education md Transportation fioSr~.

2@~ent of Comerce Science and Technology Fellow, 1989-W.

30a as5i~ent from !h.ndia National ~~ratories.

don as5i~ent ~om OTA’S Science, l%lucationj and Trmsportation PWYam.

sws Fellow, 1989-90.

v
Contents

Chapter 1. Summary ... ... ... ..** ... .**. ... ... ... ... ... ... ... ... ... ... . o.*...*""""""""""""""""""

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ........00”””

PRINCIPAL FINDINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............

Finding 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Finding 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Finding 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. .. .. .. ... ... .+.+... Finding 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Finding 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

STATE OF EXPLOSIVES DETECTOR DEVELOPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 2. Introduction ● . . . . . . . . . . . . . . . . .0...0.0. . . . . . . . . . . . . . . . . . . . . . . . . . . . ● O*....** . . . . . . . . .

THE ROLE OF TECHNOLOGY IN COUNTERING TERRORISM . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

OUTLINE OF THIS STUDY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................

Chapter 3. The Terrorist Threat .....00. . . . . . . . . . . . . . . . . . . ..000.0.. ● ......0. ● ....**.. . . . . . . . . . ● *

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............

A DEFINITIONAL FOCUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............

TERRORISM: PAST, PRESENT, AND FUTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Historical Origins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contemporary Terrorism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Two Decades of Terrorism: A Statistical Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Terrorism in the Future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

THE THREAT TO THE UNITED STATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Domestic Terrorism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

International Terrorism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .

OBSERVATIONS AND CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 4. Research and Development . . . . . . . ....0000 . . . . . . . . ● 00..... . . . . . . . . . . . . . . . . . . . . . . . . . .

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Explosives Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chemical and Biological Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Physical Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Incident Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Data Dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DETECTING EXPLOSIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Explosive Threat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Methods of Explosives Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Accelerator Technology .. .. .. . .. .. ... .. ..;...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

X-Ray Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

DEFENSE AGAINST CHEMICAL AND BIOLOGICAL WARFARE (CBW) AGENTS . . . . . . . . . .

Chemical and Biological Agents—Point and Remote Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PHYSICAL PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. .. .. .. .. .. ... ... ...+.... .+. +.....

Detectors and Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Building Hardening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Aircraft Hardening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Access Control.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...................

Baltimore-Washington International (BWI) Airport Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

INCIDENT RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .....””.....

DATA DISSEMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........

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vi
Chapter 5. Conclusions Regarding Current Research and Development Into

Detection of Explosives . . . . . . . . . . . . . . . . . ● .....0.. . . . . . . . . . ● . . . . . . . . ● O.*..*.. ...*...** 61

TESTING AND EVALUATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

MANAGING RESEARCH . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Time From Laboratory To Deployment.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

FAA RULEMAKING FOR EXPLOSIVES DETECTION SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Appendix A. Nuclear-based Explosives Detection Systems .000.... . . . . . . . . . . . . . . . . . . . . . . . . . . . ...0 67

Appendix B. X-Ray-Based Detection Systems . . . . . . . . . . . . . . . . . ..00....0 .0000.... . . . . . . . . . . . . . . .78

Appendix C. Vapor Detection Systems . . . . . . . . . . . . . . . . . ● ..0..0.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Appendix D. Chemical and Biological Warfare Agent Detection . . . . . . . . ● *.....** . . . . . . . . . ● .*... 87

Appendix E. Recent Federal Counterterrorism Research Efforts: Agencies and Their Budgets . . . 91

Appendix F. Congressional Request and Support Letters . . . . . . . . ● 0.0..... . . . . . . . . . . . . . . . . . . . . . .100

Figures

Figure Page

3-l. Distribution of Categories of International Terrorist Attacks 1970-79 and 1980-89 . . . . . . . . . . . . . . 20

3-2. Geographical Distribution of Terrorist Attacks Against U.S. Citizens and Interests, 1970-79 . . . . . 26

3-3. Geographical Distribution of Terrorist Attacks Against U.S. Citizens and Interests, 1980-89 . . . . . 27

4-l. Densities of Various Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

4-2. Nitrogen Percentage of Various Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4-3. Nitrogen Density of Various Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

4-4. Correlation Between Oxygen and Nitrogen Densities in Explosives and Other Materials . . . . . . . . 44

4-5. Relative Volatilities of Some Common Explosives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

5-1. Advantages and Disadvantages of Available (or nearly available) Explosives

Detection Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

A-1. Sketch of Apparatus for Thermal Neutron Analysis of Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

A-2. Sketch of Apparatus for Fast Neutron Analysis of Nitrogen, Carbon, and Oxygen . . . . . . . . . . . . . . 71

A-3. Sketch of Apparatus for Pulsed Neutron Beam Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

A-4. Resonant Absorption of GammaRay s . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 74

A-5. Resonant Absorption of Garoma Rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Tables

Table Page

1-1. FY 1990 Levels of Federal Funding in Research and Development Specifically

Directed at Counterterrorism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3-1. Regional Distribution of Attacks Against U.S. Citizens and Interests 1970-89 . . . . . . . . . . . . . . . . . . 25

4-1. Some Common Explosives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4-2. Explosives Detection Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4-3. Airline Crashes Caused by Terrorist Bombs, 1982-89 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4-4. Chemical and Biological Agent Detection Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

5-1. Advantages and Disadvantages of Available (or nearly available) Explosives

Detection Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

E-1. Federal Agencies Engaged in Counterterrorism Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

E-2. Allocation of FAA

E-3. Allocation of FAA

Security R&D Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Fiscal Year 1990 Contract Dollars for Major Program Priorities. . . . . . . . . . . . 98

vii
Chapter 1

Summary

INTRODUCTION

The United States has been a favored target of

terrorists for well over a decade. During much of this

time, public and governmental reaction to terrorist

atrocities committed against U.S. civilians, military

and diplomatic personnel, or property-at home or

abroad—tended to be short-lived. Typically, an

event produced a short period of anger and outrage

lasting a few days, or, perhaps, weeks. There were

occasional calls for Federal action but little of

substance was accomplished. Interest would slowly

abate until the next major incident reinitiated the

sequence. Recently, however, the U.S. response, in

attitude and action, has begun to show some staying

power.

The 1983 Beirut attacks on the U.S. Embassy and

Marine barracks, killing 258 Americans, constituted

one watershed. Following these incidents, two

investigative commissions were formed: one, within

the Department of Defense and chaired by Admiral

Robert L.J. Long, was assigned the task of investigating the bombing of the barracks; the other,

chaired by former CIA Director Bobby Inman,

investigated measures to improve security at U.S.

embassies and consulates abroad. The Long Commission recommended, among other things, a

change in national policy that would incorporate a

more proactive approach in dealing with terrorism.

The main thrust of the report, however, was to

elevate the importance of dealing with terrorism to

a national priority. The Commission considered

terrorism to be a form of warfare and to require

appropriate responses. Among these responses

would be a higher profile for those activities within

Federal agencies that were designed to protect

against or to fight terrorism. Recommendations of

the Inman Commission included a massive improvement of security at State Department facilities

overseas, including: personnel protection, building

security improvements, and design and structural

changes. Also, the post of Ambassador-at-Large for

Counterterrorism was created. A major diplomatic

security program was initiated and continues today.

Another effect of the reports was to reinvigorate

two existing but largely quiescent interagency bodies, the Interagency Intelligence Committee on

Photo credit: W~hington, DC, Metropolitan Police Department

and U.S. Capitol Police

Minor terrorism: debris from 1984 bombing of Washington,

DC, Office of the American Civil Liberties Union, in same

building housing the Off ice of Technology Assessment.

Terrorism and the Interagency Group on Terrorism,

which had been established in 1982. In 1985,

following release of these reports and in the face of

continuing terrorist attacks on U.S. targets, new

attention was given to the idea that technological

development had a significant role to play in

protecting U.S. citizens and assets from the terrorist

threat. The two interagency groups began to function

more effectively, and each created a subcommittee

on research and development.

In June 1985, TWA Flight 847 from Athens to

Beirut was hijacked. In the course of that incident, a

U.S. Navy sailor was brutally murdered, and the

world’s media were held enthralled for nearly 3

weeks while the drama played out. Following this

event, President Reagan asked then Vice President

Bush to chair a cabinet-level Task Force on Combating Terrorism. Reporting back in December 1985,

the task force recommended, among other things, an

–l–
2 ● Technology Against Terrorism: The Federal Effort

Photo credit: Fedetzd Atiatbn Administration

Flight deck of commercial aircraft destroyed by terrorist bomb; Lockerbie, Scotland, 1988.

effort to improve coordination among government

agencies, creation of a full-time position on the

National Security Council staff and establishment of

a consolidated intelligence center on terrorism. This

report further increased government interest in

dealing with the terrorist problem in a coordinated

way.

Since then, terrorist attacks on Americans and

others have continued unabated throughout the

world. However, until the 1988 bombing of Pan

American Flight 103 over Lockerbie, Scotland, U.S.

public attention to terrorism generally remained at a

low level, apart from some peaks immediately

following the 1985 hijacking of the cruise ship

Achille Lauro and a few other incidents.

Lockerbie changed all that. That event revived

deep public concern and resulted in calls for

immediate action to protect U.S. citizens. Public

opinion in other countries was also affected. This

concern and interest has not gone away. Federal

agencies, particularly the Federal Aviation Administration (FAA), were blamed for alleged laxity over

the bombing and came under severe pressure to take

major steps to improve security. Two advocacy

groups, Victims of Pan Am 103 and Families of Pan

Am Flight 103/Lockerbie, have been particularly

effective in keeping the issue before the public and

in demanding radical improvements in airline security.

In spite of increased public awareness, however,

the United States (and, indeed, the world) continues

to suffer terrorist attacks. Indeed, in late 1989, some

terrorist bombings took place in the United States

itself. l Major loss of life has also occurred in two

1989 airplane bombings in which some Americans

were victims: UTA Flight 772 over Niger, en route

1111 Dec~m 1989, two letter bombs were delivered in the southeastern part of the country. One killed a Federal judge in w- md mother took

the life of a Save G& civil rights attorney. Other letter bombs, one sent to a Federal court building and the other to the headquarters of the National

Association for the Advancement of Colored People in Jacksonville, FL, were defused. Racist letters claiming credit for the bombings were received

shortly thereafter.
Chapter 1--Summary ● 3

Photo credit: Federal Atiation Administration

Part of wreckage of commercial aircraft destroyed by

terrorist bomb; Sahara Desert, Niger, 1989.

from Ndjamena to Paris on September 19, 1989; and

Avianca Flight 203 on November 27, 1989, just after

take-off from Bogota on a flight to Cali.

In the summer of 1989, OTA was asked by three

Senate Committees to study the state of research and

development into technologies that could be of use

in countering terrorism. Requests came from the

Committee on Governmental Affairs; the Subcommittee on Terrorism, Narcotics, and International

Operations of the Foreign Relations Committee; and

the Committee on Commerce, Science, and Technology, with its Subcommittee on Aviation.2 The

three requests all asked for a study that would

explore the state of research and development of

technologies that could be useful in the battle against

terrorism. The study was approved by OTA’s

Technology Assessment Board in September 1989.

The Committee on Governmental Affairs noted

that the United States possesses a particular advantage in defending itself, its citizens, and its property:

its high level of technological development. The

Committee expressed the desire to:

. . . assure ourselves that the Nation is taking full

advantage of its capabilities in this area. While we

are aware that there is no technical fix for terrorism,

and that even the most ingenious technologies will

not prevent all attacks, technology is a vital tool, to

be used along with intelligence-gathering, law enPhoto credit: FedemlAtiation Administration

Debris from destruction of commercial aircraft by

narcoterrorist bomb; Soacha, near Bogota

Colombia, 1989,

forcement, and, where requested, military or paramilitary action.3

Letters from the first two committees asked for

abroad assessment of relevant technology development, while the request from the Committee on

Commerce, Science, and Transportation naturally

focused more on counterterrorism as applied to

airline security. In addition, this Committee also

asked for information on the state of activities in the

area of human factors, a field of study within the

social sciences that deals with the effects of human

behavior on systems. In this case, human factors

would include items such as personnel training,

ergonomics (the discipline that tries to optimize the

interface between humans and machines), management techniques, improving mental concentration,

and passenger screening by means of standard

profiles.

The Committees also requested that OTA investigate the degree of coordination among the many

agencies involved in counterterrorist work. A large

number of executive branch agencies have interests

and jurisdictions in counterterrorism, including

some obvious ones (e.g., Department of Defense, the

intelligence agencies, the Department of State, the

Federal Aviation Administration, the Department of

Energy, the Department of Justice, the Secret Service),

and some not-so-obvious players (e.g., the Environ-

% additioq a letter of endorsement for the study was later received from the Senate Select Committee on Intelligence.

3Thi5 and tie other request letters are in app. F.
4 ● Technology Against Terrorism: The Federal Effort

mental Protection Agency). Assuring adequate coordination is a serious issue.

This report, the first produced by this assessment,

gives an overview of Federal efforts to develop

technical tools to aid in the battle against terrorism. 

It also provides a detailed discussion and analysis of

technical aspects of research into explosives detectors, and gives the background of recent developments in the field. These are topics of great current

interest, particularly when applied to airport security. Further, this report also covers research into

technologies of use in other areas of counterterrorism: protection against chemical and biological

attacks, physical security, data dissemination, and

incident response. There is promising work taking

place in all these areas. Some findings are presented

along with some options for Congress regarding the

funding of research and development and the

implementation of some of the developed technologies.

The final report, due in the spring of 1991, will

contain information on additional relevant technologies, and will treat areas not covered in this one.

Among the items to be studied are: the role of human

factors, weapons detectors, structural hardening of

buildings and aircraft, systems approaches to physical security, detection of bomb mechanisms, and

exotic weapons and sensors. Further discussions will

analyze interagency and international coordination

of research efforts as well as issues surrounding the

efficient transfer of technology from the laboratory

to the field. The topic of intelligence gathering will

not be addressed in this assessment.

These reports represent further assessments by

OTA in the field of terrorism, following an initial

study, released by OTA in June 1990, which

included an analysis of the vulnerability of U.S.

electric systems to sabotage.4

PRINCIPAL FINDINGS

Finding I

The Technical Support Working Group (TSWG)

—the research and development (R&D) subcommittee of the Policy Coordinating Committee on Terrorism (PCC/T)5

--is the only interagency coordinating

group that has a broad perspective on the full range

of technology development for fighting terrorism.6

Many agencies perform such work, but each has a

limited perspective related to its specific mission.

The purpose of TSWG is to provide seed money for

important R&D that no agency has funded, usually

because the area is outside the direct concerns of any

single agency. When a TSWG project produces a

successful prototype, appropriate agencies are to

take on the role of further development and deployment. The broad agency participation is intended to

maximize expertise and to assure that unnecessary

duplication does not occur.

The downward spiral in funding the efforts of

the Technical Support Working Group, from $10

million in fiscal years 1986-87 to $7 million in

fiscal year 1988 to $3 million in fiscal year 1989

to $2 million in fiscal year 1990, has had a

significant deleterious effect on counterterrorist

research and development. The fiscal year 1990

number was the result of a compromise between the

House of Representatives and the Senate, in which

the Senate had tried to zero funding for the second

year in a row. The TSWG could usefully allocate

considerably more per year (probably up to $10

million) in worthwhile research for the foreseeable

future.

Some successful and useful efforts are being

uniquely performed under the aegis of TSWG. They

are in danger of being thwarted, due to low and

declining funding constraints placed on this

group. There is no other government body with both

the mandate and the practical ability to coordinate

R&D efforts over the entire spectrum of counterterrorist technologies. Creation of the TSWG has

greatly increased communication among scientists

of the various agencies who often are working

similar problems.

Moreover, in some areas of research undertaken

by TSWG, there is apparently little government

effort underway elsewhere. For example, it appears

that virtually no other government agency has funded

4u.s. ConWss, ~iw of Technology Assessment, Phya”cal Vulnerabili~ of Electric Systems to Natural Disasters and Sabotage, 0~-w53

(JWddngton, DC: U.S. Government Printing Office, June 1990).

s~e pCC/T is tie suwessor committee to the Interagency Group on Terrorism referred to in the p~vious section.

6~o~erwoup, tie ~teragency~telligmw Committee on Terrorism, has also recently begun funding R&D in fie countefle~rism ~~> but focuses

on technologies of particular interest to the intelligence community.

7~ exception is as~($xK),(M)c) ~r Yem) ProBam run by the kmy’s chemical Rtxx.Kk Development and Er@~*gcent~.
Chapter 1--Summary ● 5

Ptwto credit: Engimwm”ng Computer C?ptwnomks, Inc.

Transportable Emergency Response Monitoring Module,

for reacting to chemical or biological terrorist incidents,

developed by Engineering Computer Optecnomics, Inc.,

under contract with the Environmental Protection

Agency as part of the interagency research funded

by the Technical Support Working Group.

much research into developing responses to terrorist

attacks of a chemical or biological nature.7

Several factors unrelated to the quality of the

services performed by the TSWG have contributed

to its fiscal vulnerability. Currently, its funding is

lumped as a small item within the budget of the State

Department’s Bureau of Diplomatic Security. This

reduces the profile of the TSWG and makes it more

difficult for advocates to argue its case during the

funding process. Also, since monies given to the

TSWG are taken from the budget of the Bureau of

Diplomatic Security, which has other major concerns, such as adequate security staffing, support for

TSWG from within the State Department has not

always been strong. One option to solve the

funding problem would be to provide a separate

line item for TSWG in order to raise its profile for

the purposes of budgetary decision making.

Arguments to reduce or eliminate TSWG funding

appear to center around concerns that it is not

desirable to fund research out of State Department

appropriations. However, this arrangement arose for

historical reasons, in part because other agencies

were reluctant to perform this role. The research is,

however, managed by the Department of Defense,

through the Naval Explosive Ordnance Disposal

Technology Center,g which has the resources and

experience to do so. Decisions are made by a broad

interagency panel, so TSWG can only in a very

narrow sense be considered a State Department

research group. If, nevertheless, it were decided that

the State Department should not be involved as the

funding agency, one solution could be to place the

funding in the hands of another of the member

agencies, where participation in research is not in

question. If funding is to be crippled or eliminated, the decision to do so would more appropriately be made on the basis of arguments dealing

with overall need or technical detail, not on

institutional grounds.

Several promising projects have been seriously

delayed or halted because of inadequate or uncertain

funding. The Transportable Emergency Response

Monitoring Module is a case in point. The aim of this

TSWG research program (managed by the Environmental Protection Agency and produced by Engineering Computer Optecnomics, Inc.) has been the

completion of a mobile laboratory that can be

deployed to the site of a chemical or biological

attack, either threatened or real. This project has

been delayed for a year due to lack of funding.

Similar delays have occurred in a number of other

areas. Payoffs, at least in some of these delayed

projects, would probably come within 2 or 3 years if

properly funded and supported.

In spite of these difficulties, TSWG has managed

to bring several important projects from conception

through to fruition. One example is the development

of a portable protective hood, designed to be easily

carried by officials who might be at risk of attack

with chemical or biological agents. When domed,

the hood encloses the head and provides temporary

protection of eyes and airways until evacuation to a

safe site can be achieved. A number of other projects

are now nearing the prototyping stage.

Finding 2

Some promising areas of work in counterterrorist technologies are suffering from low or

intermittent funding. A total of about $70 million, allocated specifically for research into and

development of counterterrorist technologies, is

spread across about 20 Federal agencies as shown

in table 1-1.9

SIMS enti~ is m~ged by tie Na~, butswed jointly by all services to conduct R&D for the entire Department of Defense comm@tY.

%additio~ R&D in otber fields (e.g., low-intensity conflic~ counternarcotics) may produce useful products for counterterrorism.
6 ● Technology Against Terrorism: The Federal Effort

Apart from the general availability of Federal

funds, two important, independent criteria are used

to determine the level of resource allocation for

research and development in a particular area: the

importance of the work to national goals and the

degree to which technological progress would benefit from funding. The first criterion is, in part,

subjective. The second is more quantifiable, although with uncertainties that become larger, the

further technical development is projected into the

future.

While, in practice, it is difficult to justify the

importance of R&D to national goals, the relative

funding of various efforts affords a de facto measure

of their relative importance. The $70 million

annual expenditure on counterterrorism R&D is

roughly 0.7 percent of defense R&D at equivalent

levels of development (including the defense 6.1,

6.2, and 6.3A items, i.e., research and early

development). This provides a measure of the

perceived importance of the effort relative to

national security goals. The counterterrorism R&D

funding is also about 4 percent of the annual budget

of the National Science Foundation and 3 percent of

the fiscal year 1991 appropriation for the space

station. This provides a measure of of its perceived

importance relative to basic R&D budgets.

Some observers have suggested that since terrorism only affects the lives of a few hundred, or at

worst, a few thousand persons per year-those of the

victims and their families-the direct impact on the

Nation is small. By this standard, as tragic as loss of

life to terrorism may be, tobacco, other drugs, or

drunk driving may pose much more serious problems for the United States. Such a point of view

could support reemphasizing research into counterterrorist technologies and devoting more effort to

solving those problems.

Another point of view, however, holds that

terrorism, beyond affecting the lives of many Americans, has also had a strongly negative effect on the

ability of the United States to conduct its foreign

policy, on the ability of U.S. businesses to operate

and compete throughout the world, on U.S. prestige

in general, and on the freedom of U.S. citizens to

travel without undue fear in many parts of the world.

From this viewpoint, terrorism is a pernicious

Table 1-1—FY 1990 Levels of Federal Funding in

Research and Development Specifically Directed at

Counterterrorism (not complete)

Funding

Agency (millions of dollars)

Technical Support Working Group . . . . . . . . 2

Department of Energy . . . . . . . . . . . . . . . . . . 10a

Federal Aviation Administration . . . . . . . . . . 13

Naval Explosive Ordnance Disposal

Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Other Military Services . . . . . . . . . . . . . . . . . 16

Other Department of Defense agencies . . . 14

Others . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . about IOb

a Targett~ alrn~t exclusively agahst threate to nUCkH fadities.

b lncl~~ the FBI, the Secret ~rv~e, and the @st~mS ~rv~e. The

relevant research budgeta of these appear to be extremely low. The FBI,

in particular, is unable to pursue many promising research projects,

especially in the area of explosives detection, because of the minuscule

amount of resources available (Iessthan $100,000 per year). The Central

Intelligence Agency refused to provide relevant information.

SOURCE: Office of Technology Assessment, 1991.

scourge that affects U.S. national interests and

national security far beyond its impacts on the lives

of those most directly touched.

The “Irangate” affair provided a striking example of terrorism’s ability to have serious and

negative repercussions on the conduct of foreign

policy, on U.S. prestige, and, potentially, on the U.S.

military posture in the Middle East. A series of

terrorist acts (i.e., kidnappings), was used by the

Iranian authorities to extort policy changes from the

U.S. Government (i.e., arms sales to Iran), which

would otherwise have been rejected by the United

States as inimical to its interests. Terrorism can have

a multiplicative impact that is well beyond its

immediate casualties.10

If it is decided that the threat of terrorism is

more significant than indicated by the fraction of

current military and other security-related R&D

expenditures devoted to counterterrorist technologies, this would argue for an increase in resources. This does not imply that additional funds

for R&D in countering terrorism should necessarily

be taken out of the military R&D budget, which

deals not only with terrorism, but all other military

aspects of national security. Rather, the $40 billion

for all military R&D indicates a scale of effort that

is useful in helping to determine the appropriate

level of effort for R&D into counterterrorism technologies.

lo~o~ere~ple is the case of hijacked TWA Flight 847, in which the crew and hostages were fiually set free iu retUrn fOr the prOmiSe (hlter cd~

out) of the release by Israel of a large number of arrested Shi’ites, some of whom had been involved in terrorist activites. It is a virtual certainty that

some of those released again took up their interrupted task of terrorism. Thus, one terrorist act was able to multiply itself into many terrorist acts.
Chapter 1--Summary 7 7

The other consideration in determiningg the appropriate amount of R&D is the degree of maturity of

the given research. Several important areas of R&D

in counterterrorism are now funding-limited (i.e.,

progress is limited by available funding).ll One

example was noted under Finding 1, above. Appendixes A through D discuss a number of further

examples of projects that have the promise of

producing useful prototype instruments after a few

years of assured and adequate funding.

Finding 3

OTA finds that requiring the mass acquisition

of thermal neutron analysis (TNA) devices for

installation at airports at this time is inadvisable.

In September 1989, the FAA established a rule

outlining regulations that would eventually require

the use of an Explosives Detection System (EDS) to

screen checked (not carry-on) baggage in many

airports serving U.S. carriers.12 In this rule, the FAA

Administrator was given the option of implementation at his discretion.

The only equipment currently deemed acceptable

and approved as an EDS by FAA is based on a

technique called thermal neutron analysis (TNA).

The device was developed by Science Applications

International Corp. (SAIC) under contract to the

FAA Technical Center. This approval was given,

however, based on restricted tests made under less

than optimal conditions and without the concurrence

of the Technical Center.13 The machine uses lowenergy neutrons to produce interactions with the

nuclei of nitrogen atoms (nitrogen is usually found

in high proportions in explosives). As a result of

these interactions, the nitrogen nuclei produce

gamma radiation of a specific energy, which is

detected and identified. The utility of this detector

for finding bombs of the size that caused the

Lockerbie crash has been widely questioned. A

series of test results has confirmed doubts that the

device would have a false-alarm rate low enough for

14 Other proposed explosives practical applications.

detectors (some based on TNA and some not) that

are available today in prototype or more advanced

form are not yet more effective than the SAIC model,

although many are smaller and those on the market

are cheaper.

The rule was apparently established in response to

strong public pressure and congressional action that

led to the enactment of Public Law 101-45 on June

30, 1989.15 The law requires the FAA Administrator

to initiate action to:

. . . require the use of explosive detection equipment

that meets minimum performance standards requiring application of technology equivalent to or better

than thermal neutron analysis technology. . . as the

Administrator determines that the installation and

use of such equipment is necessary to ensure the

safety of air commerce. The Administrator shall

complete these actions within sixty days of enactment of this Act. . .

The original TNA machine was not able

simultaneously to: a) detect the smallest quantities

of plastic explosives that could destroy an aircraft

and b) maintain manageable false-alarm rates that

would not hopelessly disrupt airline operations if it

were used for all baggage. l6 Moreover, the exclusion

of carry-on baggage from this rule provides immediate alternatives for the terrorist to pursue. Ironically,

TNA would probably be more effective against

explosives transported in carry-on baggage because

the background coming from gamma radiation

produced by innocent luggage would be less.

By itself, the original TNA device could not

reliably protect against bombs like the one that

brought down Pan Am 103, except to the degree that

it might act as a deterrent to some terrorists.

However, no other device for detecting explosives

has yet shown itself more capable than the TNA

system. It is possible, but by no means assured, that

in the future, TNA or other technological tools will

l~R&D Proj=ts Ca be mtig.wt~ or technology-lirhited. III the latter case, additionrd funding will not bring simlcant additional Progress.

12Fede~ Register, Sept. 5, 1989.

13 See Report of the %esident’s Commission on Aviation Security and Terrorism, W*hhgto~ ~, May 199Q p. 65.

14A f~5e @ is an ~diation by me machine titthe object bei~ s~eyed con- a l~ge ~o~t of ~trogen in a relatively SIIldl VOhUIle, wh~

the object actually contains no explosives.

15some congessio~ s~feeltitthe Presage of this law wm based onmiscomm~cation between~e FM ~d Congress regardi.ngthe pe’ifOXrEUKe

capability of the TNA device-personal communication from staff of the Presidential Commission on Airline Security and Terrorism June 15, 1990.

16Thereis a~adeoffbe~=nsemitivi~ ~d f~se-~~mte. Reduc~g he ~eshold to detect s~er~tities of explosives irlCK!&3eS the fd3e-dilKLl

rate signiilcantly.
8 ● Technology Against Terrorism: The Federal Effort

prove adequate to the task. However, no particular

technology should be locked in until it works.

The resistance from airlines and airports to the

FAA rule has demonstrated the difficulties that can

arise from premature issuance of rules requiring

corporations to make large expenditures to acquire

devices that are operationally burdensome and of

limited utility. Requiring installation of any device

that is costly and complicates operations will

naturally meet with institutional and individual

resistance. This could be overcome if it were shown

that the equipment added significantly to airline

safety and security. If, on the other hand, it cannot be

shown that devices that satisfy stringent performance standards actually exist, massive resistance to

such rules, both from within the government and

from the private sector, will persist. This is the case

today.

If the costs for such devices become very burdensome to the private sector and if they are, nevertheless, deemed essential, an alternative solution would

be government participation in funding. But if, as is

the case, they are not capable of doing the required

job, it makes no sense to deploy them.

There is a tradeoff: increasing security in a

meaningful way will cost money and will likely raise

operational difficulties for commercial air transportation. Congress and the American public will have

to decide what level of expenditure and operational

inconvenience is an acceptable cost for augmenting

the safety of air travel.

On the positive side, well thought-out regulations

should stimulate interest in developing useful technologies for explosives detection, since a potential

market worth up to hundreds of millions of dollars

would be created. This is what FAA tried to do,

probably prematurely, in response to congressional

mandate and public pressure.

Testing a limited number of TNA machines at

airports, as is currently planned and being done,

serves a useful purpose, even if TNA turns out not to

be the ultimate technical choice. The operational

experience that will have been gained in applying

explosives detectors online to passenger baggage

under real conditions will provide invaluable information for devising specifications, standards, and

practices for future systems. Similar operational

evaluation should be carried out for other promising technologies or for other versions of the

TNA approach, whether or not the R&D was

originally funded by FAA. Some other technologies, 17 as well as Some other TNA manufacturer%

should be candidates for such evaluations in the

near future.

Finding 4

Testing protocols for FAA’s proposed Explosives Detection Systems (EDS) need to be established. Any acceptance test that will lead to

mandated acquisition and use of a given device

ought to use a testing procedure that is credible

and acceptable.

Further, because of past problems regarding

testing procedures, a testing authority independent of the FAA is urgently needed to sort out the

divergent claims made by various sponsors of

research and interested private corporations.

After new testing procedures and authorities are

established, the TNA device should undergo a

new acceptance test to remain in consideration as

one of the possible technologies. FAA has funded

research in this area for several years. Because of its

decisions during the last few years of funding

research, the FAA is, correctly or not, perceived by

many as having an institutional stake in particular

technologies.

The FAA has been funding work on developing

explosives detectors since 1977. Vapor sniffers for

detecting explosives have been supported since

1984, and TNA development at SAIC has been

sponsored since 1985. The increased effort in the

mid-1980’s was stimulated by various hijackings

and terrorist incidents, especially by the bombing of

an Air India flight from Montreal to London in 1985.

FAA officials have reported an annual expenditure

of about $8 million per year between 1985 and 1989

on explosive detector research.

In the fall of 1989, FAA issued a Broad Agency

Announcement, asking for proposals for developing

technologies in the area of airline security. Systems

studies of combined technologies were specifically

included in the announcement, as well as research

ITSome examples are: a) computerized tomography, based on x-ray and computing technologies, that would produce a detailed ~e~emio~

image of an object; b) dual energy or back-scatter x-ray technologies that provide information on the atomic weight of objects as well as their densities;

and c) vapor detectors that “sniff” the objecg looking for molecules found in explosives. See ch. 4 and apps. A, B, and C.
Chapter 1--Summary . 9

into individual technological areas (e.g., explosives

detection, metal detection, weapons detection, aircraft hardening against explosions). This positive

step should expand the scope of FAA-sponsored

research to include work to develop proactive

technologies against future threats in contrast to

previous R&D, which was largely reactive. FAA

should proceed to make this projected research

program a reality as soon as possible.

The TNA system prototype developed by SAIC

was given ‘‘acceptance tests’ at San Francisco and

Los Angeles Airports in 1987 and 1988. These tests

were devised in part by SAIC itself, were not

double-blind (there was no attempt to conceal from

the operators or observers which of the tested

baggage had the explosive), and have been severely

criticized by experts outside the FAA. They were

designed to detect a minimum quantity of plastic

explosive, an amount thought by some at the time to

be a reasonable goal. The Lockerbie experience has

indicated that a much smaller amount can bring

down a Boeing 747. The design criteria of the

apparatus and the acceptance test based on those

criteria should therefore be considered insufficient.

From this point on, any acceptance test for explosives detection should meet stricter criteria.

In early 1989, after the Lockerbie event, the FAA

tested a vapor detection device in their Atlantic City

Technical Center at the request of the manufacturer,

Thermedics, Inc. A well thought-out, double-blind

protocol was established that was stricter (although

it used the same large quantity of explosives) than

the original unblinded TNA acceptance tests. The

device did not perform well in these tests, although

in some cases plastic explosives were detected. The

vendor then complained, not without cause, that

their system had been called on to pass a test

significantly more stringent than had the TNA

device.

As a first step to remedying this confusing

situation, protocols for running the evaluation tests

need to be formulated. Some possible candidate

organizations that might be appropriate for providing protocols are the National Academy of Sciences,

Sandia National Laboratory, Los Alamos National

Laboratory, and the National Institute of Standards

and Technology (formerly, the National Bureau of

Standards). In the private sector, the American

Society for Testing of Materials (ASTM) is also

working on developing test standards. The FAA is

currently trying to develop new protocols with the

help of Sandia and an advisory board, including

members from various agencies and the academic

world.

Once protocols are established, the government

should decide who will perform the acceptance

testing. The past controversy over the acceptance of

TNA has led to calls from many quarters for an

independent testing authority .18 Although nearly all

observers agree that an independent testing authority

is desirable to assure objectivity and credibility,

there is less agreement on who that authority should

be.

A choice acceptable to all stakeholders might be

the National Institute of Standards and Technology,

supported by an oversight board composed of

representatives from the national laboratories, academia, and industry. Developing accepted standards

for engineering equipment is one of NIST’s historic

roles. NIST has recently performed some testing in

this area, but has not participated in any developmental work.

Another suggestion for a contractor to perform

acceptance testing is Sandia National Laboratory,

which has distinguished itself as expert in this field

over the past decade. However, Sandia scientists

have tended to focus on a limited number of detector

technologies. Further, as a participant in explosives

detector research and development, Sandia has a

stake in the outcome in terms of allocation of

research dollars. Proponents of other technologies

might therefore feel disadvantaged if Sandia were to

be the Nation’s testing body for explosives detectors, in part out of a fear that those technologies on

which Sandia has worked might be unduly favored.

This reflects a common difficulty in such matters: if

an institution has a long track record of work in a

given area, perceptions may be that it has developed

internal biases. Similar arguments might be applied

to other National Laboratories, such as Los Alamos.

The perception may not be accurate, but may still

exist and cast doubt on the results of the testing. On

the other hand, if the institution has little or no track

lgs~temen~ of SUppOrt for an independent testing authority have been made to OTA staff by an ex-Director of SWUX@ for Fw, by some vendors,

and in public and private by FAA officials.
10 ● Technology Against Terrorism: The Federal Effort

record, perceptions are that its competence may be

limited.

A further point concerns acceptance of any EDS

at foreign airports. U.S. regulations require foreign

air carriers to meet certain security criteria for those

flights landing in the United States, under threat of

revocation of domestic landing rights. Other countries may view U.S. regulations on the activities of

their air carriers at their airports as violations of

sovereignty. This problem could be eased by foreign

participation in evaluation of candidate devices at an

early stage. In general, international cooperation in

both research and setting standards is essential to the

establishment of effective security for international

air travel.

Finding 5

Solving airline security problems will require

not only technical equipment, but a systems

approach that makes intelligent use of the technologies available. Immediate attention should be

given to developing combined approaches to

airline security that could be applied with current or near-current technologies as soon as

possible.

As yet, no single explosives detector technology

is adequate by itself against all reasonable threats.

Until and unless a technological “magic bullet”

appears on the scene, the civilized world must take

what protective action it can with the means at hand.

A role for TNA and other technologies in monitoring

checked baggage may well be possible in this

context. However, if properly sequenced, combinations of technologies from among x-ray, vapor

detection, and nuclear techniques, such as TNA,

may be much more effective, much harder to

countermeasure, and much more of a deterrent to

potential malefactor than any single method.

Additionally, since a large fraction of bombs

planted on aircraft have been brought on board

via carry-on baggage rather than in checked

luggage, this path must be blocked as well. Efforts

are needed to address in parallel the problem of

detecting the introduction of explosives aboard

aircraft by either route.

In addition to combinations of technical systems, the use of human factors techniques, such

as enhanced security personnel training and

supervision, along with methods of passenger

screening, could play a strong role in improving

security in commercial air travel. The apparent

low level of activity in investigating the role of

human factors—in developing passenger profiles, in

human performance, and the man-machine interface-seems to be a weak link in R&D programs

aimed at improving airline security.

Since the Lockerbie bombing, there has been

strong public and Congressional pressure to upgrade

airline security to improve significantly the security

of the traveling public. This is natural, understandable, and reasonable. Airline security has been

inadequate in dealing with the threat of surreptitious

introduction of explosives on aircraft, particularly

plastic explosives. These pressures explain the rush

to mandate the use of the best device available.

However, current TNA equipment is expensive, bulky, time consuming, and (while the best

device available) has definite limitations. Other

currently available technologies may be cheaper

and less bulky, but they are even less effective

than TNA. Therefore, these other technologies

should not yet be mandated either.

The difficulty is that no single current technology

can yet, by itself, provide reasonable assurance of

detection of bombs the size of the Lockerbie device,

while permitting adequate throughput of passengers

and baggage, and providing an acceptable level of

false alarms. This is today’s reality. Further, if one

assumes relatively straight-forward efforts by terrorists to countermeasure detection devices, today’s

technology appears even less imposing. This may

not be the case in the future, but the current state of

affairs will last for at least a year or two, probably

longer.

Until newer methods of detection are available,

security could be upgraded in a number of ways.

●

●

Additional procedures could be instituted and

personnel hired to provide hand inspection of

all suspect baggage. Improvements could be

made in hiring, training, pay, motivation, and

management of security personnel. Some efforts to this end have been made by FAA in

concert with the Air Transport Association, an

organization of commercial airlines. Whether

these planned improvements are sufficient is

not yet clear.

Passenger screening by profiling could be

greatly expanded, using interviews, as is done
Chapter 1--Summary ● 11

●

on El Al (Israel’s airline) flights, and, in fact, is

done on U.S. carriers in some locations.19

These efforts would be labor-intensive and

costly, but could be introduced reasonably

rapidly.

Security systems could employ simultaneously

several less-than-perfect technologies that are

now (or will soon be) available. Such a systems

approach, combining different technologies,

could be applied after some preliminary screening, would be far more difficult to beat, and

would introduce great additional uncertainty

for the terrorist.

In combining technologies, the strengths of some

technologies could compensate for the weakness in

others. For example, following screening by passenger profiles,20 a fraction of bags could be selected for

further investigation.21 This might be followed by an

x-ray device and vapor sniffer (far cheaper and

smaller than TNA and smaller, cheaper, and quicker

than tomography) that would pass on to a TNA or

tomographic system only those bags that were still

questionable. Finally, those bags still failing the

tests could be fed to a device based on nuclear

techniques that would finally prompt either the

opening of the bag in the presence of the passenger

or else its disposal. In such a system, far fewer of the

slower, expensive, bulky systems would be needed

per airport, and the whole system would be a serious

deterrent, since there would be so many different

techniques for the terrorist to try to deceive.

This particular combination of devices is only

meant as an example, not a suggestion for a workable

airline passenger security system. The point is, that

with today’s or next year’s technology, a more

effective and imposing system can be devised by

combining several different ways of doing the

same thing, rather than relying on only one

technique. Depending on false alarm rates, the total

cost of such a system for a major airport could be less

than requiring a TNA system to inspect every piece

of checked baggage.

STATE OF EXPLOSIVES

DETECTOR DEVELOPMENT

The original TNA system cannot reliably detect

bombs the size of the Lockerbie device with an

acceptable false alarm rate. It is also very expensive

per unit, and is large and heavy. Vapor detectors

rely, in part, on surface contamination for detection,

and, while some technologies, such as the chemi1uminescence-based detector developed by Thermedics, Inc., are sensitive to plastic high explosives

of concern, they are not currently sensitive to all

explosives. There are, as yet, no reliable data on

vapor detectors’ ability to perform detection at

satisfactory sensitivity in an airport environment.

X-ray techniques are too easily confused. They

also have not yet been automated to the point where

the machine can, without human intervention, reliably decide whether to pass an item or to sound an

alarm, although some vendors are addressing this

problem, and may succeed, to some degree, in the

near future. Such automation has been mandated in

the FAA rulemaking to eliminate too heavy dependence on decision making by the operators of the

security devices, who are typically unskilled, poorly

paid, and unmotivated. Computerized tomography

is at an early stage and currently takes too long per

bag for application by itself. However, one vendor,

Imatron, hopes to demonstrate a solution to this

problem in the near future. Like TNA, it will be

expensive (although probably less so), large, and

heavy.

There are several technologies that may possibly

be ready for introduction in 1 to 5 years. Some of

these are upgrades of previously mentioned technologies, which all (including TNA) can be improved.

Computerized tomography may soon be in a position to play a useful role. There are others. The

utilization of more energetic (“fast”) neutrons,

which could permit the detection of elements other

than nitrogen (this element, or chemical radicals

containing it, is currently used as the signature for

lgAIthou@thi,s ~s t. be done ha competent f~hion. A report on the Public Broadcasting System’s television program, FrontZine (J~. 2% 1990),

asserted that at least one interviewer in Frankfurt did not understand English and although able to ask the questions phonetically, could not understand

the responses.

20Se~~ Pmsome. mightlook for ~spicio~ si@s. mere ~so my& patte~ of bebvior specKIc to “mules,” thOSe lmslls pecting individuals

who are deceived into unwittingly carrying explosives onto a flight. Research needs to be done into developing up-to-date profiles characteristics of both

terrorists and unwitting accomplices, in terms of both general data and response to carefully selected questions.

210ne ~ssibfi~is the re&~ematc~g of passengers with the~ luggage, S0 that no bag re~s on the Wcrdt if the corresponding pWX3eIlger k

not on the aircraft as it rolls away from the gate. This is now required on international flights behveen the United States and certain foreign airports. This

could be facilitated, for example, by barcode tagging.
12 ● Technology Against Terrorism: The Federal Effort

nearly all explosives detection other than x ray),22

may one day be practical at some level. With fast

neutrons, carbon and oxygen could also be detected.

Determiningg the ratios of carbon to nitrogen and

carbon to oxygen would reduce false alarms and

allow detection of non-nitrogen-containing explosives as well. Another technology that shows some

promise is the use of high-energy gamma rays to

probe for nitrogen nuclei by means of an enhancement in absorption of the rays at a well-defined

energy. Many of these avenues may appear promising now but significant developmental work still

needs to be done for each. In a following report,

OTA will examine options for future FAA research

programs in this field in more detail.

Only after prototypes are well tested in the field

by independent authorities should the government

mandate mass acquisition of equipment that would

represent a major expenditure. However, initial steps

to issue rules requiring equipment acquisition could

stimulate a technology push, if undertaken at a

point when the technology appears to be close to

meeting the requirements.

m~eremea few explosives that contain no nitrogeu although they are generally unstable and hard to handle.
Chapter 2

Introduction

THE ROLE OF TECHNOLOGY IN

COUNTERING TERRORISM

There is no technological fix for terrorism. It will

never be possible to prevent all random, or nearly

random, acts of murder and mayhem against innocent individuals or institutions, whether in the name

of political or religious ideals or for any other cause.

A frequently expressed viewpoint holds that

terrorism can only end when its root causes are dealt

with. This point of view is not only defeatist, but

without substance: the root causes of all terrorism

will not be removed for a very long time. There are,

across the world, persistent conflicting political,

social, and economic claims. Moreover, there will

probably always exist frustrated and unstable individuals, delighted to devise an ideological or theological excuse to commit unconscionable acts.

Further, there are many instances where terrorism is

employed on both sides of an issue. Ending the root

causes of terrorism on one side could well aggravate

the root causes on the other. In addition, for some

states, terrorism has become a useful alternative way

of doing business. These states have an interest in

seeing terrorism continue.

These arguments do not deny the wisdom or

legitimacy of efforts to satisfy real grievances

among different groups of people in the world. But

we should harbor no illusions of total and permanent

success in ending terrorism by resolving political

grievances, particularly in the near term. Meanwhile, common sense and common decency dictate

a search for ways to defend the innocent from the

depredations of the enraged.

It maybe impossible to end terrorism, but we can

try to reduce our vulnerabilities (and, thereby, the

likely number of terrorist incidents) to the greatest

degree possible, consonant with the requirement to

maintain a free and open society. Many terrorist acts,

particularly those against transportation systems and

against visible freed sites (e.g., embassies, military

bases) can be deterred, prevented, or mitigated by

judicious use of technological tools, when employed

in conjunction with antiterrorist and anticriminal

methods. Although not a fix, technology is and will

continue to be a highly useful tool in the ongoing

battle. It will probably play a far greater role in the

future than it does today.

This report elucidates some of the means by

which technology may be brought to bear on the

problem of terrorism and provides some options for

Congress to help facilitate the effort.

OUTLINE OF THIS STUDY

This OTA report is the first of two deliverables of

this assessment. It includes, inter alia, a review of

many relevant Federal activities and provides some

details on the state-of-the-art for a number of fields

of research. It also discusses the near-term prospects

for deployment of useful tools in some of the better

known areas of counterterrorist technology. It is,

however, by no means complete. This study contains

a detailed discussion of only a selected list of

technical topics, although an outline of a good part

of the Federal research is given.

Chapter 3 discusses terrorism in the world and in

the United States from a historical perspective, to

provide a basis for extrapolating the likely threat that

will appear in the near and more distant future. As

well as accounting for the progressive improvements

that may be expected in technical sophistication of

terrorist groups, particularly those with state sponsorship, decisionmakers must also allow for the very

real possibility of qualitative changes in the terrorists’ scope of activities.

While little, if any, terrorist activity has yet been

manifest in the chemical or biological arenas, most

observers agree that the technical capability for

designing weapons based on these agents is not

beyond the abilities of a large number of currently

active terrorist organizations.l Given the availability

of these weapons in the Middle East, there is the

l~e use and production of chemical weapons by several states in the Middle East has been frequently reported in the press an4 in P= by

intermtional observers, over the past few years. Such weapons were used by both sides, especially Iraq, in the recent Iran-Iraq War. In one case, Halabja

in 1988, the Iraqis apparently were responsible for the deaths of thousands of Iraqi civilians by means of chemical agents. Another example of developing

capability is the famous Rabta ‘phrumaceutical” complex in Libya, revealed by the U.S. Government in 1988, and the object of renewed international

focus in March 1990.

–13–
14 ● Technology Against Terrorism: The Federal Effort

possibility of a terrorist attack employing chemical

or biological weapons in the near future. In fact,

counterterrorist research is being undertaken by the

Technical Support Working Group (see apps. D and

E) to deal with this possible future threat. Chapter 3

discusses the topic briefly and the final report will

examine the matter further.

Chapter 4 outlines many of the specific lines of

research being pursued and discusses the prospects

of near-term success for a number of technologies,

particularly those dealing with detection of explosives. While not exhaustive, this section of chapter

4 provides a fairly comprehensive picture of the

various possibilities for useful detection and the

likelihoods of success for several approaches.

This chapter also discusses some work that has

been done in the area of countering chemical and

biological terrorism, both in the realm of early

detection and portable protection and decontamination. An outline of ongoing work in several other

areas is also included, such as barriers and alarms,

weapons detectors, weapons neutralization, and data

dissemination. There is also a discussion of efforts

in the area of integrated airport security systems,

which includes some of the technical topics discussed above as well as efforts to design effective

systems from the technological components.

Chapter 5 presents some conclusions on research

and development relevant to explosives detection,

especially in the context of airport security.

The bulk of the technical analysis in this report is

contained in appendixes A through D, which deal

with explosives detectors, their variety, current

capabilities, and the institutional, financial, and

technical barriers to their immediate widespread

deployment at airports around the world.

Appendix E presents an overview of Federal

research in the counterterrorist area, from the

perspectives of both individual agencies and interagency cooperation. It provides a quick look at the

level of spending on R&D, giving the reader an

overview of where most of the effort is going, both

in terms of technology and agency. This view is not

complete, in part due to the refusal of the Central

Intelligence Agency to provide OTA with data and

in part due to time constraints. However, it does

provide a general picture of the level of intensity of

related work and of the agencies involved.

There are two threats that will not be dealt with by

either part of this assessment in great detail. One is

nuclear terrorism, that is, terrorism that relies on the

threat or use of either nuclear weapons or the

dispersal of toxic radioactive agents. Since this topic

has been widely analyzed in the last few years, and

since research in this area (mostly funded by the

Department of Energy and the Defense Nuclear

Agency) has been very active and productive for

well over a decade, this study will only touch on it.

The other is attacks against computer systems. The

matter of computer security against disabling attacks

has not been considered a counterterrorist item until

recently. There are many activities in this area, both

in government and in the private sector. This topic

is markedly different from other forms of terrorism

and is being widely examined elsewhere. It is also a

crime against property, rather than against persons

(with some rare possible exceptions, such as attacks

on hospital databases). Therefore, beyond a short

mention, it will be considered beyond the scope of

this assessment and will not be handled here.

Several technical and other topics are not covered

in this report, but will be discussed in the subsequent

one. One such topic includes the use of human

factors studies and related sciences. Human factors

have potential applications in:

. screening passengers at airports;

● motivating and assisting security personnel;

. dealing with crises, such as hostage-taking; and

. helping predict future activities of terrorists.

Another topic to be dealt with in more detail in the

next report is the set of technologies useful in

protecting freed sites, such as embassies, from

attack. This includes barriers and access control

technologies and techniques, and also the design and

engineering of buildings and grounds to discourage

attacks and mitigate them if they do occur. Yet other

topics for further discussion in the final report

include hardening technologies to protect aircraft

and more exotic techniques (other than standard

firearms and other usual weapons) for responding to

hostage-holding incidents.
Chapter 3

The Terrorist Threat

INTRODUCTION

Political developments in 1989 and early 1990

throughout the world have led to a kind of euphoria

that Americans have not known since the end of

World War II. The tearing down of the Berlin Wall,

the democratization of East European countries, and

the decline of communism have been much welcomed by Americans of most political persuasions.

In addition to the developments in the communist

world have been the recent changes towards democracy in other countries, such as the toppling of the

Marcos dictatorship in the Philippines, the progressive installation of democratically elected governments in Latin America, and the winds of change in

South Africa symbolized by the release of Nelson

Mandela, the leader of the African National Congress (ANC), and the relegalization of the ANC and

other anti-apartheid groups.

However, terrorism remains a vital threat to the

security of the United States as well as other powers,

large and small. The recent changes in the world

have not diminished the dangers of terrorism—

including new dangers created by the forces of

extreme nationalism. Since the late summer of 1990,

Iraq and its allied subnational groups have reminded

us graphically of this.

This chapter presents perspectives on the nature,

scope, and intensity of the terrorist threat affecting

contemporary society and U.S. security interests.

A DEFINITIONAL FOCUS1

Many governments and peoples of the free world

have failed to appreciate the magnitude and implications of the terrorist threat. Some democracies tend

to regard terrorism as a minor nuisance or irritant. As

a result, a large number of pluralist societies have not

developed a strong commitment to deal effectively

with the problem of terrorism.

A major reason for this failure is a definitional and

moral confusion over what constitutes terrorism.

The media, as the most critical instrument reflecting

the perspectives of the perpetrators and opponents of

terrorist acts, reinforce the confusion about terrorism.

It is prudent to distinguish among terms used to

describe terrorism. Terrorism is perceived differently by perpetrators and by victims. To the attackers, whoever stands by a just cause cannot possibly

be called a terrorist. . "2 On the other hand, the

diverse origins and semantic justifications of terrorist acts are irrelevant to the victims.

Moreover, the definitional focus of each sovereign government depends frost and foremost on the

nature of its internal and external policies. Every

sovereign state reserves to itself the political and

legal authority to determine what is and what is not

terrorism in the context of domestic and foreign

affairs. For instance, the United Kingdom applies

the term to the Provisional Irish Republican Army

(PIRA), and Israel regards all violent acts by the

Palestine Liberation Organization (PLO) as terrorist.

As a pluralist democracy, the United States speaks

with a bewildering variety of voices on the subject

of terrorism. Under the U.S. Federal system, each

state determines what constitutes an offense under

its criminal or penal code. An increasing number of

States have defined terrorism generically as a crime,

thus evading the need for use of specific statutes

covering other selected criminal acts that are identified as terrorism.3 Also, Congress has, over the past

20 years, held hearings, considered numerous bills,

adopted resolutions, and passed laws on terrorism.4

IFor SoUceS on he deffitio~ i~~ue~ of tem~~m ~~ well ~ for litera~e on the gener~ topic of terrorism, see, for exqle, Yonah Alexander (cd.),

Terrorism: An International Resource File, 1980-85 Index, 1986 Index, 1987 Index, and 1988 Index (Ann Arbor, MI: UMI, 1986-89), and Edward F.

Mikolus with Peter A. Flemming, Terrorism, 1980-1987: A Selectively Annotated Bibliography (Westpo~ (3’: Greenwood Press, 1988). For a specific

treatment of the issue of definition see, for instance, Brian M. Jenkins,“The Study of Terrorism: Definitional Problems” (Santa Monica, CA: RAND

Corp., December 1980).

~asser Arafat at the U.N. General Assembly, 1974, as quoted by Secretary of State George Shultz in a speech in New Yorlq Oct. 25, 1984.

Ssee, for example, Artimas c~ Code, Title 41, Sec. 41-1608, stating that “a person commits the offense of terroristic threatening if with the

purpose of terrorizing another person he threatens to cause death or serious physical injury or substantial property damage to another person.”

dsee, for ~s~nce,H.R. 25o7 (lolst Cong., 1st sess., my 25, 1989), a bill initiated to establish a commission On aViatiOn securiw and terrofism,

seeking to investigate the destruction of Pan Am 103 on Dec. 21, 1988, and KAL 007 on Aug. 31, 1983.

–15–
16 ● Technology Against Terrorism: The Federal Effort

Nevertheless, a comprehensive working definition

that can address the different forms of terrorist

activity has not emerged from the Congress thus far.

Similarly, the executive branch, partly as a result

of the very nature of its jurisdictional diversities, has

not developed a coordinated position on the meaning

of the term. For example, the Federal Bureau of

Investigation (FBI) defines terrorism as ‘the unlawful use of force or violence against persons or

property to intimidate or coerce a government, the

civilian population, or any segment thereof, in

furtherance of political or social objectives. ”5 The

Central Intelligence Agency (CIA), has specified

that:

. . . international terrorism is terrorism conducted

with the support of foreign governments or organizations and/or directed against foreign nations, institutions, or governments.6

In recent years, however, both the Department of

State and the Department of Defense adopted a

definition that has been commonly used by the U.S.

Government and which reflects:

. . . a middle ground within the broad range of expert

opinion, both domestic and international.7

Accordingly, State and Defense see “terrorism” as:

. . . premeditated, politically motivated violence perpetrated against a noncombatant target by subnational groups or clandestine state agents, usually

intended to influence an audience. “International

terrorism’ is terrorism involving the citizens or

territory of more than one country.8

An analysis of these as well as numerous other

definitions indicates that although there is a lack of

consensus in public and private views on the

subject, 9 the following elements are essential in

what can be considered as “terrorism’

1. Nature of the Act: The concept of terrorist

violence or threat of violence clearly embraces

criminal, unlawful, politically subversive, and

2.

3.

4.

5.

6.

anarchic acts-piracy, hijacking of aircraft,

taking of hostages, and other offenses of a

political character.

Perpetrators: States as well as individuals and

private groups may be perpetrators.

Strategic and Other Objectives: State sponsorship of terrorism is often part of a campaign of

geographic expansion of political control.

More recently, some terrorism has had as its

political objectives the furtherance of illicit

business operations. The prime example is the

narcoterrorism waged by drug cartels in Colombia.

Intended Outcomes and Motivations: Fear,

extortion, radical political change, and measures jeopardizing fundamental human freedoms of innocent parties are most often the

expected immediate results. The ultimate goal

usually is the satisfaction of political demands

that the group does not feel able to achieve by

conventional political, economic, or military

actions. Terrorism is often born of such

frustration.

Targets: Human beings and property are both

targets of terrorist acts, with special focus on

heads of states, diplomats, public officials, and

military targets in noncombat or peacekeeping

roles.

Methods: Threats, as well as the actual use of

violence, including kidnapping, hostagetaking, and murder are the common weapons

of terrorists in spreading fear among the

targeted population.10

On the basis of the above components, it is

reasonable to adopt the following as a working

definition of terrorism:

The deliberate employment of violence or the

threat of violence by sovereign states or subnational groups, possibly encouraged or assisted by

sovereign states, to attain strategic or political

objectives by acts in violation of law intended to

5u.s. Department of Justice, FBI, Temon”sm in the UnitedStates J988 (Terrorist Research and Analytical Center, comterte~oti SeCtiO% ~

Investigative Divisio~ Dec. 31, 1988), p. 34.

6“pattem of~temtio~ Terrorism: 1980,’$ a rm~ch paper prepared by the National Foreign Assessment Center, Washington DC, P. ii._

is a Central Intelligence Agency publication and is based on information available as of Dec. 31, 1980.)

~.S. Department of Defense, Terrorist Group Profiles (Washington DC: U.S. Government Printing Office, 1988), p. viii.

g~id. See &W U.S. D~~ent of State, Parterns of GZobuZ Terrorism: 1988 (w@klgtoIL DC: Wch 1989), p. viii.

gsee, for exaple, Alex P. Schm.id, and Albert J. Jongmw, Political Terrorism (Amsterdam: North Holl~d I%blishing CO., 1988), pp. 1-39.

Iomy S. Ctie and yo~~e=nder develo~d thew elements in an unclassified report prepared for the U.S. Army on “state-sponsored Terrorism”

(1985), pp. 22-23.
Chapter 3—The Terrorist Threat ● 17

create a climate of fear in a target population

larger than the civilian or military victims attacked or threatened.ll

Since terrorism represents the use of severe

psychological and physical extra-legal force, typically directed against innocent victims, it is a

violation of fundamental human rights, contrary to

international law, and flouts the letter and spirit of

the U.N. Charter and other relevant multilateral

treaties.

TERRORISM: PAST, PRESENT,

AND FUTURE

Historical Origins

Terrorism, as a cost-effective tool of low-intensity

conflict that projects psychological intimidation and

physical force in violation of law, has ancient roots.

Mostly religious in motivation, terrorists systematically utilized swords and daggers during antiquity

and the Middle Ages in their violent holy campaigns. Examples are the operations of the Jewish

Zealot Sicarii, directed against Roman rule in

occupied Judea as well as Jewish political and social

enemies, and the martyrdom missions of the

Hashashin (assassins), an offspring of the Ismailis,

targeting the Crusaders and Sunni adversaries in

Persia, Syria, and elsewhere in the Middle East. The

former were active for 70 years in the first century

and the latter lasted some 200 years-from the 1lth

to the 13th centuries. Their experience has proven

that terrorism can be attractive, effective, and

durable, even if its tools are rather primitive.12

In subsequent periods, several European maritime

states between the 16th and late 18th centuries

employed pirates, or privateers, to terrorize the seas

for the purpose of advancing foreign policy objectives. By the time of the “reign of terror” (1793-

1794) during the French Revolution, terrorism from

“above’ and ‘‘below’ was commonplace. A variety of European groups nourished by anarchistic

theories, left- and right-wing ideologies, and nationalism, have attained some tactical successes. Resorting to regicide and other terrorist activities such as

bombing, extremists assassinated a considerable

number of European rulers and ministers, including

Tsar Alexander II in 1881. Although not intended by

the perpetrator, the murder of the Austrian Archduke

in Sarajevo drew the powers into World War I.

The period in the 20th century between the World

Wars also witnessed terrorist violence in different

regions of the world, such as Asia and the Middle

East, where nationalist groups fought for liberation

from colonial rule.13

Contemporary Terrorism

In the late 1960s, terrorism became a constant

future of international life. Unique political circumstances led to this development, including the

Six-Day War of 1967 and the rise of Palestinian

terrorism worldwide; the adversarial relationship

and physical proximity of the United States to Cuba,

leading to numerous aircraft hijackings; the Vietnam

War and the universal reaction against it; and the

Paris students’ revolt in 1968. These events, coupled

with rapid developments in modern technology,

communication facilities, and inexpensive and rapid

travel, have contributed to the proliferation of

indigenous and international terrorist groups and to

the intensification of ideological and political violence.14

Another factor contributing to the expansion of

contemporary terrorism is the role of certain states.

A number of nations, such as Iran, Syria, Libya, and

North Korea have sponsored terrorist operations as

a form of secret or undeclared warfare in situations

where overt or declared warfare would be inconvenient. Because modern weapons and all-out wars are

1lIbid., p. 37.

IZSCC, for example, David c. Rappaport and Yonah Alexander (eds.), The Morality of Terrorism: Religious and Secular Justifications (New York

NY: Columbia University Press, 1989).

lssee, for ins~m, w~ter~uew, The Age of Terrorism (Bosto~ MA: Little, Brown& Co., 1987); and Walter Laqueur and Yonah Mexander (eds.),

The Terrorism Reader (New Yorlq NY: New American Library, 1987).

ldFor some genti~ work on contempor~ terrorism see, for example, Yonah Alexander (cd.), International Terrorism: National, Regional, and

GZobal Perspectives (New Yorlq NY: Praeger Publishers, 1976); Yonah Alexander, David Cadto~ and Paul Wilkinson (eds.), Terrorism: Theory and

Practice (Boulder, CO: Westview Press, 1979); Yonah Alexander and Seymour M. Finger (eds.), Terrorism: Interdisciplinq Perspectives

(Maidenhead, England: McGraw Hill, 1978); and Robert Kupperman and Jeff Kamen, Final Warning (New York NY: Doubleday, 1989). For an

exhaustive survey of domestic and international groups see, for instance, Peter Jardce, Guern-Ila and Terron”st organizations: A World Directory and

Bibliography (New York NY: Macmilla~ 1983); and Henry W. Degeti Political Dissent:An International Guide to Dissident, Extra-Parliamentary

Guem”lla and Illegal Political Movements (Detroi4 MI: Gale Research Co., 1983).
18 ● Technology Against Terrorism: The Federal Effort

so expensive and destructive, these states, ideologically inclined to fight nations they perceive as

enemies, may wish to restrict themselves to lowintensity conflict. In this mode, they attack their

adversaries but confine their violence to the lower

end of the spectrum of conflict, well away from the

high-intensity of open, organized military hostilities. Since state sponsors of terrorism can engage in

operations with little risk of being held accountable

for their actions, they are usually not subject to

reprisals by the target states.15

It is these political circumstances and technological and military realities that have led both subnational groups and state actors to employ violence or

the threat of violence to attain political, social, and

economic objectives in violation of law. As perpetrators, they became linked with each other. Many

major terrorist groups around the world have at some

point maintained a director indirect connection with

a state sponsor. Some terrorist organizations appear

to function at the exclusive service of certain states.

In addition, over the past 10 to 15 years, collaboration among ideologically linked bodies and even

among those without a common philosophy or

political orientation has increased substantially.l6

A case in point is the Japanese Red Army (JRA).

JRA broke away from the Japanese Communist

League Red Army Faction and established a distinct

group in 1970. Aiming to form a People’s Republic

in Japan and to support a Marxist-Leninist revolution throughout the world, the JRA maintains ties

with abroad range of movements inside and outside

Japan. It has links with several other groups, such as

the Popular Front for the Liberation of Palestine

(PFLP), and maintains a base under Syrian control

in Lebanon’s Beka’a Valley. It also enjoys the

support of Libya and North Korea and has set up

terrorist cells throughout Asia, including Hong

Kong, Manila, and Singapore.

The JRA has attacked, inter alia, U.S. targets,

including American passengers at Lod Airport in

Israel (1972); U.S. business facilities in Singapore

(1974); U.S. embassies in Jakarta (1986), Rome

(1987) and Madrid (1988); and a USO club in Naples

(1988). Yu Kikumura, a JRA member, was arrested

with explosives on the New Jersey Turnpike in April

1988 and was subsequently sentenced to 30 years

imprisonment.

In addition to the JRA, other groups, acting

independently or as surrogates for some states, have

resorted to pragmatic and symbolic terrorist acts

(e.g., arson, bombing, hostage-taking, kidnapping,

and murder) for the purpose of producing pressures

on governments and people to accede to the demands of the perpetrators. Their attacks have victimized, killed, and maimed large numbers of innocent

civilians.

Terrorist acts have also inflicted considerable

damage on targets other than people. Besides

government offices and police stations, terrorists

have attacked many property targets, usually those

sites that either have many innocent persons present

or have strategic importance (e.g., powerlines or

pipelines) .17

IsSee, for~tmce, Rays. cl~e ~d yo~~exander, Terrorism as State-Sponsored Covert Wu?jare @ti=, VA: HERO Books, 1986); and Yom

Alexander, “State-Sponsored Terrorisq” Harvurd International Review, vol. 7, No. 6, 1986, pp. 21-23.

IsSee, for exmple, Yonah Alexander and Robert A. Kilmi_u_x (eds.), “International Network of Terrorist Movements,” Political Terrorism and

Business (New Yorlq NY: Praeger Publishers, 1979), pp. 34-56; and Claire Sterling, “The Great Bulgarian Cover-Up,” The New Republic 192:21, 1985,

pp. 16-21.

ITChronolo@es of terrorist events US* for this Pawr include a variety of sources, such as press indexes; FBIS; NEXIS; Facts-on-File; U.S.

Government reports such as those published by the FBI, Department of Defense, and Department of State (e.g. Bureau of Diplomatic Security, Signi@nt

Incidents of Political Violence Against Amen-cans, 1988); annuals such as Yonah Alexander (cd.), The 1986 Annual on Terrorism (The Netherlands:

Martinus Nijhoff, 1989); Edward F. Mickolus, Todd Sandier, and Jean M. Murdoclq International Terron”sm in the J980’s: A Chronology of Events,

Vol. ZZ, 1984-1987 (Ames, IA: Iowa State University Press); yearly reporta of terrorist events prepared by the Project on Low Intensity Warfare of the

Jaffe Center for Strategic Studies of Tel Aviv University (JCSS), such as the latest publication INTER: Znternationd Terrorism in 1988 (JerusaJem: The

Jerusalem Post 1989); the chronologies published by theRAND Corp. on different types of terrorism (e.g., Brian M. Jenkins et al., “A Chronology of

Terrorist Attacks and Other CriminalActions Against Maritime Targets, ” (Santa Monica, CA: The RAND Corp., September, 1983); and the information

on terrorist attacks research by the Institute for Studies in International Terrorism, State University of New York.
Chapter .3-The Terrorist Threat . 19

Two Decades of Terrorism:

A Statistical Overview

The statistics of both domestic and international

incidents are startling.18 During the decade of the

1970s, the total number of incidents worldwide was

8,114. There were 4,978 people killed and 6,902

injured. In terms of geographic distribution, Europe

was the most active region, with a total of 3,598

incidents. Latin America followed with 2,252 incidents. The third region affected was the Middle East

with 1,097 incidents. The most targeted victim

during the 1970s was the business community, with

a total of 3,290 incidents recorded.

The next decade was even more intensive in scope

and destructive force. In 1980, 2,755 attacks were

registered and their number increased to a record

high of 4,422 in 1989, a 16-percent increase over the

previous year. The 1980s saw a grand total of 31,426

incidents, with 70,859 killed and 47,849 injured,

reflecting a lethality trend of more attacks designed

to kill random victims. Figure 3-1 contains a

summary of data on terrorist attacks.

Unlike the previous decade, in the 1980s the most

violent terrorist region was Latin America, where

18,173 incidents were recorded. It is followed by

Europe, with 4,613, Asia with 4,302, and the Middle

East with 3,060.

Another approach to survey the nature, scope, and

intensity of terrorism during the past two decades is

to focus on its international character rather than

deal with both domestic and foreign cases. According to the U.S. State Department database that

records terrorist events involving the citizens or

territory of more than one state,l9 the pattern of

operations by subnational groups and state sponsors

underscores a constant global rise in number of

incidents.

In 1970, a total of 309 international operations

were recorded; this figure more than doubled in two

decades, reaching 661 incidents in 1989. overall, in

the 1970s, a total of 4,234 international acts were

perpetrated, with 2,783 killed and 4,799 wounded.20

The primary target was the business community

with 1,011 incidents recorded. Targets also involved

diplomats (967), government officials (255), and the

military (173)?

The decade of the 1980s marked a substantial

increase in the number of international terrorist

incidents and casualties. Overall, 6,501 operations

were registered, with a total of 5,042 killed and

11,702 wounded. Shifting of the regional distribution of international terrorist incidents during the

1980s also occurred. Whereas in the 1970s Europe

led the world in such incidents, the Middle East

became the predominant location of international

terrorist attacks in the 1980s. As in the preceding

decade, the primary target of the 1980s was business

with a total of 1,630 incidents.

Terrorism in the Future

In 1990, both domestic and international terrorism

touched the lives and interests of individuals and

nations in every region of the world. Some examples

underline the diverse nature of recent incidents: a

bomb exploded at the Chilean-U.S. Cultural Institute in Santiago; in Medellin, Colombia, a military

judge was shot (one of very many murders there in

recent years); a former Defense Minister was assassinated in Peru; and in Guatemala, a left-wing union

leader from El Salvador and an activist were killed.

Elsewhere, a 1,000-pound bomb placed in a van

exploded in Northern Ireland demolishing an unmanned police station and damaging 50 houses;

Spanish deputies were shot in a Madrid restaurant;

and a bomb killed two people and wounded two

others in a bus terminal in Agdam, Azerbaijan. Also,

18s~ti~@ ~ntenorismvvwidely, -ydepen~onthedefiitiom employed byrese~chers+ Numerous &tabanks focus undomestic terrorism

intermtiomdterrorism, state terrons~ terrorism in specific countries, etc. Also, interpretation of these statistics differ, depending onthebody organizing

the &ta. A major private statistical source for both domestic and international incidents is the database of Business Risks International (BRI) located

in Arlington VA. It has issued monthly and quarterly reports since 1979, which are sold to subscribers. Some of the statistical material has been reprinted

elsewhere in such publications as Terrorism: An International Journal and the annuals on terrorism, both edited by Yonah Alexander. The statistical

material used in this section is drawn from BRI sources in dealing with both domestic and internatiotuil terrorism. Other statistical databases consulted

for this paper include JCSS and RAND materials.

lgAv~able uncl~sified U.!j. State Depwment figures cover the years 1968-1989. The stat.isticrd information for this period wtis provided by the

Office of the Coordinator for Counterterrorism. Some of the statistical material is available in State Department publications such as Patterns of Global

Terrorism, op.cit., footnote 8, and Significant Incidents of Political Violence Against Americans, op.cit., footnote 17.

~Accordfig to the state Department data, the incident figures may exceed event totals due to overlapping.

211bid.
20 ● Technology Against Terrorism: The Federal Effort

2 0

15

10

5

0

Figure 3-l-Distribution of Categories of International Terrorist Attacks

1970-79 and 1980-89

Thousands

m 1980-1989

m 1970-1979

200

150

-

100

50

nw

L

Hijackings Maimings

Bombings Facility Hijackings

Attacks

SOURCE: U.S. Department of State, 1990.

9 Israelis were killed and 17 were wounded in a

tourist bus ambushed in Egypt; the Mayor of

Nagasaki was wounded by extreme right-wing

assailants; and a British member of Parliament was

murdered by the Provisional IRA (PIRA). Towards

the end of the year, the Speaker of the Egyptian

Parliament was murdered by terrorists, and in 1991,

the PIRA succeeded in launching a mortar attack on

10 Downing Street, disrupting a British cabinet

meeting.

The Gulf War and its preliminary crisis brought

several international terrorist groups together to

offer their services to Iraq. In addition, a large

number of (mostly minor) terrorist incidents occurred throughout the world after the onset of

hostilities in 1991. Many of the latter attacks were

apparently independent of Iraqi control and due to

local, established terrorist groups that wished to

express solidarity with Saddam Hussein and against

the coalition nations.

While it is expected that similar kinds of incidents

will occur in the forseeable future (i.e., terrorists will

use a wide range of conventional weapons—guns,

Kidnappings Maimings Assassinations

bombs, plus more sophisticated weapons, e.g.,

man-portable anti-tank rockets and surface-to-air

missiles), the arsenal of tomorrow’s terrorist might

include instruments of mass destruction as well.

The specter of nuclear terrorism, such as the theft

or detonation of a nuclear bomb, the use of

fissionable material or intensely radioactive waste as

a radioactive poison, or the seizure and sabotage of

nuclear facilities, is seen by many experts as

plausible and by others as inevitable.22 At this time,

however, more likely forms of nuclear terrorism

would include a credible hoax involving a nuclear

device, holding a nuclear facility or a shipment of

highly radioactive material for purposes of political

or economic blackmail, or dispersal of radioactive

medical isotopes.

While the probability of a serious and successful

nuclear terrorist episode remains low, the consequences in terms of mass destruction could be

enormous. For example, if a crude, l-kiloton nuclear

device (one-thirteenth the size of the Hiroshima

bomb) were detonated (having been either stolen or

built by a terrorist group with exceptional resources

~For det~led s~~es S= pad ~ven~~ and Yonah Alexander, Preventing Nuclear Terrorism (Lexhgtoq MA: bxington Press, 1987); ad pad

Leventhal and Yonah Alexander, Nuc/ear Terrorism: Dejining the Threat (McIx!aQ VA: Pergarnon-Brassey ’s, 1986).
Chapter 3--The Terrorist Threat .21

and talent) in a major city, it could cause more than

100,000 fatalities and damage totaling billions of

dollars. The human, physical, and psychological

consequences of such an incident would be far more

catastrophic than those of Three Mile Island (where

there was no detectable loss of life but considerable

financial damage) and the Chernobyl accident

(which was caused by operators who overrode safety

systems in a negligent, but not malicious reamer)

which killed several dozen people outright, injured,

or killed thousands of others, and caused severe

property losses and untold damage to the environment.

Most experts agree, however, that it is easier to

acquire the technical capability to produce chemical

or biological weapons than it would be to produce or

steal nuclear weapons. These weapons, like nuclear

ones, are capable of producing enormous numbers of

casualties in a single incident (perhaps up to several

hundred thousand fatalities in a worst case, considering biological agents) and causing governmental and

societal disruption of major proportions and widespread public panic.23 Biological and chemical

weapons have many advantages for terrorists. They

include low cost as well as ease and speed of

production; further, these weapons can, in principle,

be developed by individuals with no more than a

college-level education in the relevant field and with

limited facilities. Weapons development requires

only a minimum amount of tools and space, and

equipment can be improvised or purchased without

arousing suspicion.24

Further, many states are known to have chemical

or biological weapons programs. The existence of

the Libyan chemical weapons plant at Rabta has

become common knowledge, especially since the

fire at the site that at first was thought to have caused

its destruction.25 Besides this well-known chemical

plant, chemical and biological weapons facilities

exist in Iraq and chemical facilities have been

reported in Iran. The development of such capabilities has been confirmed by leaders of both nations.

The United States has developed chemical weapons,

but decided to abandon the development of biological weapons.

Iraq and Iran have actually used chemical weapons on the battlefield.26 Sixteen nations are known

to have chemical warfare agents and another 10 are

alleged to possess them.

27 According to publicly

reported information, some 10 to 15 nations also

possess an offensive biological warfare program.

Will terrorist organizations acquire chemical or

biological weapons, either on their own or from

some state sponsor? According to some experts, the

odds are perhaps even or slightly higher that such an

attack will eventually occur.28

Terrorist organizations with a few skilled technicians (available to some terrorist groups for another

task—bomb design) could easily amass the requisite

capability in short order. Biological weapons are

probably easier to develop technically and are more

effective than chemical weapons. Because many

biological agents persist and (if living agents) may

multiply and spread, they can cause far-reaching

epidemics. Thus, they should be considered to be a

much greater potential threat than chemical agents.

A recent report prepared for the U.S. Armed

Forces Medical Intelligence Center by the RAND

Corp. discusses arguments for and against the

likelihood of terrorist use of biological weapons.29

In it, the technological barriers to use were not found

Zsee, for fi~ce,Brian M. Jeti and ~edp. Rub~ “New Vulnerabilities and the Acquisition of Nw W~POnS by NoWov~~~t ~ouPss”

in Alona E. Evans and John l?. Murphy (eds.), Lega/Aspects of International Terrorism (Lexingtoq MA: Lexington Books, 1978) pp. 221-276; David

Carltonand Carlo Schaerf, The Dynamics of the Arms Race (London: Croom Hehq 1975), pp. 170-93; and Jeremiah Denton, “International Terrorism:

The Nuclear Dimension” paper presented at a Conference on Nuclear Terrorisu Washington, DC, June 25, 1985.

~See, for e~ple, Richard Dean McCarthy, The Ultimate jolly: War by Pestilence, Asphyxiation andDefoZiarion (New York NY: Random House,

1969); and Stockhohn International Peace Research Institute, The Rise of CB Weapons: The Problem of Chemical andBiological Wa?fare, vol. 1 @Jew

York, NY: Humanities Press, 1971).

25~ter ~po~s ~ve cat doubt on tie effects of tie f~e and even on whe~er the fie VVaS real or a subtefige that did 1itie aCt@ damage.

26see Seti Cms, The Genie Unleashed: Iraq’s Chem”cal andBiological Jveaponsproducfi”on(was~g@~Dc: The wd)k@onhlStihlte for Near

East Policy, 1989)

ZTU.S. General Accounting office, “Chemical Warfare: Progress and Problems in Defensive Capability,” a report to the Chairman of House of

Representatives Foreign Affairs Committee, GAO PEMD-86-11, July 1986.

XE. HW-W@ ‘TerrOriStS and Chemical/Biological Weapons,” Naval War College Review, 35:36-40, 1982; and H.J. McGeurge, “The Deadly

Mixture: Bugs, Gas, and Terrorists, “ NBC Defense and Technology International 1:56-61, 1986.

29jefieyD. SfiomTenori$t$a&the potential use ofBiological weapon~ Discussion ofpossibilitiesR-3771.mc,(Santa Monica, CA: The

RAND Corp., December 1989).
22 ● Technology Against Terrorism: The Federal Effort

to be ‘‘insurmountable. The main problem to

evaluate was the potential willingness to use such

weapons, given their heinousness and the possible

adverse reaction of the terrorists’ own support base.

Further, the employment of biological weapons is

not as subject to user control as most other weapons

and would require the terrorists to become familiar

with a weapon technology that is substantially

different from what they may be used to.

The RAND report concluded that some of the

negative aspects of the use of biological weapons

(from the terrorist perspective) might be becoming

less important. The trend of mass killings through

terrorist acts has been recently observed in multiple

airline bombings, and one might foresee a reduced

reluctance on the part of terrorists to take the lives of

thousands of innocents since it has been demonstrably acceptable for them to take the lives of hundreds.

The use of chemical and biological agents by

terrorists is not without precedent. For example, in

1978, a group identifying itself as the Arab Revolutionary Army Palestinian Commandos claimed they

injected Israeli citrus fruit with mercury. An indication of the interest of at least one terrorist group in

biological warfare was the factory for making

botulinum toxin found in a raid on a hideout of the

Red Army Faction in Paris in 1980.30 Even in the

United States, there have been incidents. One of the

better known was allegedly perpetrated by a senior

member of the Rajneesh cult in Antelope, Oregon in

1985, when among other similar incidents, bacteria

were apparently used in an attempt to poison the

food of a public official. And a few years ago, an

extreme right-wing group, the Order of the Rising

Sun, in St. Louis, MO, attempted to acquire the

biological agent that causes typhus.

Biological weapons are, in some aspects, well

suited to terrorist activities. They are small, easily

concealed and transported, and readily activated.

Some relatively crude forms are easily obtainable

such as the common food poisons of salmonella,

shigella, and staphylococcus, which can be procured

from local clinical laboratories. They are readily

grown in batches and can be dispersed in water. The

extensive food and water hygiene and inspection

practices of most industrialized countries might,

however, complicate their effective use in food and

water. Some agents can be dispersed as aerosols, but

this requires greater skills on the part of the attacker.

State-sponsored terrorist organizations would appear to be the most likely to resort to biological

warfare agents. They might have easier access to

them; they could have the skills for handling and

dispersing them and might wish to attack those

targets most susceptible to such weapons, i.e., large

populations in distant places, public buildings, or

embassies. As noted above, several terroristsponsoring states have R&D programs in this

domain. Of particular concern is a statement made

by Iranian President H. Rafsanjani in a speech to

“Islamic Fighters:”

We should fully equip ourselves both in the

offensive and defensive use of chemical, bacteriological, and radiological weapons. From now on,

you should make use of the opportunity and perform

this task.31

The examples of the attempted terrorist use of

chemical and biological weapons in the past, statements on the part of leaders in some countries that

are state sponsors of terrorism regarding the development of such weapons, and independent evidence

on R&D efforts in some of those same countries, all

indicate that the use of such weapons of mass

destruction by terrorists in the future must be

considered.

Although possession of such weapons by states

that sponsor terrorism does not guarantee that

the weapons or technology would be given to the

terrorists, the possibility of such a technology

transfer, whether intentional or not, cannot be

excluded and should raise serious concerns. The

recent example of the transfer of chemical weapons

technologies from the Federal Republic of Germany

to Libya indicates that such occurrences are possible

even in a well-structured society with laws forbidding such behavior. Such transfers might be more

difficult to prevent in less stable societies.

%oreign Broadcaat Information Service, Da. 19, 1980, p. 8.

qlForei@ Broadc~t ~omation SeNice, Oct. 7, 1988, attributed to Tehran Domestic Rdio Service, oct. 6, 1988.
Chapter 3-The Terrorist Threat ● 23

THE THREAT TO THE

UNITED STATES

Domestic Terrorism

There have been occasional outbreaks of terrorism in the United States during the past 200 years

perpetrated by both domestic and foreign groups.

Some of the earliest “home-grown” groups include

the vigilantes, originally organized to keep law and

order in the lawless Western frontier; the Ku Klux

Klan during the post-Civil War period; and the

Molly Maguires, whose primary interest was vengeance against the anti-Irish-Catholic Scotch, Ulster, Welsh, and English Protestants in Pennsylvania

during the 1870s.32

In the turbulent 1960s a proliferation of radical

groups with violent tendencies occurred.33 The

Weather Underground, the New World Liberation

Front, the George Jackson Brigade, the Symbionese

Liberation Army, the Black Liberation Army, and

the Black Panther Party, were among the most active

of such left-wing groups in the United States during

the late 1960s and 1970s. During the same period

ethnic and nationalist groups (e.g., the Jewish

Defense League, Armenian movements, Puerto

Rican Armed Forces of National Liberation, Omega

7-Cuban Nationalist Movement, and the Cuban

National Liberation Front) operated within the

United States and Puerto Rico.

Although these groups have proved to be less

professional and successful than their counterparts

in other regions around the world during the 1970s,

terrorist campaigns in the United States targeted the

police, military, business, and other victims in over

600 attacks.34 In justifying their operations, terrorists have communicated a multitude of rationalizations. For instance, in a statement claiming credit for

the bombing of the Gulf Oil Building in Pittsburgh

in June 1974, the Weather Underground explained

that the attack was to punish the corporation for

“financing the Portuguese in Angola, stealing from

the poor in the U. S., and exploiting the people and

resources of 70 countries. ” The Jewish Defense

League targeted Soviet facilities, residences, and

vehicles as well as commercial firms or the installations of Eastern European countries in the New York

area to protest the policies of the Soviet Bloc toward

their Jewish minorities and Israel.

In addition to terrorism perpetrated by indigenous

groups in the 1970s, foreign nationalist groups were

also active in the United States. For instance, the

Croatian group Otpor (Resistance) hijacked a TWA

Boeing 727 from New York to Paris in 1976 to

attract attention to its separatist goal of independence from Yugoslavia and took over the West

German Consulate in Chicago in 1978 to demand the

release of a Croatian leader in Cologne. The Secret

Army for the Liberation of Armenia, seeking revenge for Turkey’s genocide against Armenians

during World War I, assassinated Turkish consular

officials in Los Angeles during 1973. Also, the

Black September Organization, operating within the

framework of Fatah, the main group of the Palestine

Liberation Organization (PLO) headed by Yasser

Arafat, killed an Israeli air attache in Washington,

DC, in 1973.

During the 1980s, the United States experienced

fewer terrorist incidents domestically than abroad.

According to FBI data, terrorist acts within the

United States declined drastically after the first few

years of the decade.35 The total number of terrorist

activities, both of indigenous and foreign origin,

reached an estimated 220, approximately one-third

that of the previous decade. The highest number of

incidents were committed between 1980 and 1982

(122). Conversely, in 1989, only six cases were

investigated as terrorist incidents, the lowest number

in any given year during two decades of violence. A

major reason for this encouraging trend has been the

success of the proactive operations of the FBI and its

32see, for ~xaple, Hu@ Davis Grti and T~ R~bertG~, violence in America: Historical and comparative perspectives (NeW YOr~ NY:

Bantam Books, 1970).

33see, for fi~nc.,Regiom[RiskA~se~~ment:No~hAmerica (Wexandria, VA: Risks ~ternatioti,kc., Augllst 1979); ‘ ‘Report of tie PoliCy Shldy

Group on Terrorism” (New York State: The Criminal Justice Institute, November 1985); and Brian M. Jenkins, “Terrorism in the United States,” TVZ

Journtd, vol. 5, No. 1, 1984, pp. 14.

34rbid. See ~so Disorders ad Terrori~m, Repofi of tie Task Force on Disorders and Terrorism (was-ton, DC: Natioti Adviso~ (.%m.m.ittee On

Criminal Justice Standards and Goals, 1976).

35 See r)ep~ment of Justice, ~1, Tewori~~ in the unitedstate~ 1988, Op<cit., footnote 5, p. 11. see also statement by OMver B. Revell, ASSOCiate

Deputy Director-Investigations, FBI, before an open session of the Committee on Government Affairs, U.S. Senate, Sept. 11, 1989. For an overview

of the domestic and international terrorist threat to the United States, see ‘‘Public Report of the Vice President’s Task Force on Combatting Terrorism, ”

February 1986.
24 ● Technology Against Terrorism: The Federal Effort

effective cooperation with other law enforcement

agencies in the United States and abroad. Prosecution of terrorists, such as the 1986 indictment by a

Federal jury in Boston of eight radicals involved in

a 9-year series of bombings, bank robberies and

murder, has also been a contributing factor in the

decline of domestic terrorism. Another factor has

been a social phenomenon—the general loss of

revolutionary fervor in the United States during this

period.

To be sure, some of the terrorist groups operating

in the 1970s were also active to some extent during

the 1980s. There were left-wing groups such as the

Weather Underground and the Black Panther Party,

both involved in the Brinks armored car robbery in

1981 in Nyack, New York; the Armed Forces of

National Liberation claimed 11 bombings in 1982.

Also, the Jewish Defense League was active, engaging in violence against its perceived enemies.

In addition to these and other domestic groups, a

variety of new bodies committed to ideological and

political violence emerged during the 1980s. The

most recent example of a group of terrorist attacks in

the United States has been the series of letter bombs

addressed to various lawyers and court officials in

the southeastern United States at the end of 1989. A

note claiming credit for the bombings implied racist

motivations. Other examples of recent U.S. terrorism include reactionary right-wing movements advancing anti-Semitic and white supremacist causes

as well as antigovernment and antitax beliefs (e.g.,

Aryan Nations) and the Evan Mecham Eco-Terrorist

International Conspiracy (EMETIC), desiring to

preserve the ecological systems by attacking perceived despoilers of the ecology through acts of

sabotage (“ecotage”). Another example is the

Animal Liberation Front (ALF) and related groups,

dedicated to the elimination of animal use in medical

research and industry. Animal rights groups in the

United States have usually confined attacks to

destruction of property, rather than humans. An

exception, however, was the attempted murder of the

president of U.S. Surgical Corp. by means of a

bomb. In the United Kingdom, two animal rights

bombings recently occurred-in one, a young child

passing by was seriously injured.

Foreign groups have also continued their operations in the United States during the past decade. For

example, the PIRA maintained a gun-running ring in

1982, and Sikh terrorists were prevented from

destroying an Air India aircraft at Kennedy Airport

in 1986 (although they had succeeded in Canada the

year before). In addition, there is some evidence that

foreign governments, such as Libya and Iran, have

put in place in the United States an infrastructure to

aid in carrying out terrorist acts. One possible

example was the 1989 San Diego pipebomb attack

on the car of the wife of Capt. Will Rogers, the

commanding officer of the USS Vincennes, which

had inadvertently shot down a civilian Iranian

airliner with massive loss of life in 1988.

In short, although the general level of domestic

terrorist activity has been reduced to relatively low

proportions during the past decade, the potential for

future attacks by both domestic and foreign bodies

remains intact. One reason for this situation is the

fact that many of the root causes of terrorism are

perceived by potential perpetrators as being unresolved. Another factor is the inevitable emergence of

new political, economic, and social problems that

will encourage terrorism.

There is no evidence available to indicate that any

U.S.-based terrorists have the intention or the

capability to mount large-scale operations. Nevertheless, there are circumstances under which terrorism might escalate considerably within this country.

For example, were the United States to intensify its

war against the narco traffickers at home and abroad,

terrorist acts in the United States could ensue.

International Terrorism

U.S. citizens and interests have been more affected by ideological and political violence abroad

than they have at home. Indeed, during the past two

decades, the United States has become a major target

of acts of terrorism throughout the world. There are

many factors contributing to this situation, including

the fact that the United States maintains an extensive

cultural, political, economic, and military presence

abroad and that a considerable number of foreign

groups and governments oppose American values,

policies, and actions. This reality, coupled with

other global developments such as technological

advancements in weaponry and communications,

has resulted in the expansion of international terrorist activities against the United States.
Chapter 3—The Terrorist Threat . 25

Statistical Data

Available statistics indicate the magnitude of the

challenge to the United States. According to one

nongovernmental database, the total number of

international terrorist incidents directed against the

United States during the past two decades was 1,617

(1970s—738; 1980s—879), with 915 killed

(1970s—215; 1980s—700), and 1,149 wounded

(1970s—314; 1980s—835).36 The U.S. State Department’s more extensive database offers a different set of figures.

37 According to it, during the same

period, the total number of attacks against U.S.

citizens and interests abroad reached 3,458 (1970s—

1,705; 1980s—1,753), killings-722 (1970s—151;

1980s—571) and woundings-764 (1970s—227;

1980s—537) persons. According to the breakdown

of U.S. victimization, the business community has

been the primary target with 1,114 incidents registered, followed by the diplomatic community with

562 incidents, and the military with 438 incidents.

Table 3-1 shows the number of attacks as a function

of location; these data are also displayed in figures

3-2 and 3-3.

While the number of attacks has fluctuated, the

overall percentage of the number of attacks against

U.S. targets has risen sharply since 1975. For

example, in the period 1975-79, attacks against U.S.

interests abroad accounted for only 8.5 percent of the

world total of terrorist incidents. In 1983, the

percentage reached 35 percent of the world total,

dropping to 26 percent in 1986, and slightly lower

than 20 percent in the past 2 years.38

Targets and Tactics

An analysis of American victimization in international terrorist attacks in the past two decades

demonstrates a wide range of civilian and military

targets. For instance, every kind of U.S. business

activity abroad has been affected, including financial (e.g., Merrill Lynch), banking (e.g., Bank of

America), energy (e.g., Texaco), chemicals (e.g.,

Union Carbide), automobiles (e.g., Ford), communication (e.g., International Telephone & Telegraph),

computers (e.g., International Business Machines),

Table 3-l—Regional Distribution of Attacks Against

U.S. Citizens and Interests 1970-89

Attacks

Region 1970-79 1980-89 Total

Latin America . . . . . . . . 520 769 1,289

Western Europe . . . . . . 598 583 1,181

Middle East . . . . . . . . . 274 148 422

Asia . . . . . . . . . . . . . . . . 138 172 310

North America . . . . . . . 130 25 155

Africa. . . . . . . . . . ./. . . 42 52 94

Eastern Europe . . . . . . 3 4 7

SOURCE: U.S. Department of State, 1989.

travel (e.g., American Express), and many others. In

addition, every segment of the U.S. military abroad

has been affected. The personnel, facilities, and

operations of the Army, Air Force, and Navy have

become a continuing target.

The tactics and tools utilized by terrorists in their

attacks against U.S. targets overseas also varied

widely in their nature. The following examples are

typical:39 incendiary devices (e.g., U.S. Government

employees’ cars in Greece, January 1973); mid-air

explosion (e.g., Pan Am 103, Lockerbie, December

1988); car bomb (e.g., Occidental Petroleum,

Bogota, February 1988); suicide truck bombing

(e.g., U.S. Embassy Annex in East Beirut, September 1984); kidnapping (e.g., Lt. Col. William Higgins in Lebanon, February 1988); hostage-taking

(e.g., U.S. Embassy in Tehran, November 1979);

assassination (e.g., Assistant U.S. Army attache,

Paris, January 1982); and hijacking (e.g., TWA 847,

June 1985).

From these examples as well as from numerous

other cases,40 it is seen that terrorists attacking U.S.

targets overseas have employed weapons and tactics

ranging from primitive to sophisticated and modern.

As far as the technological aspects of bombing are

concerned, the devices ranged from home-made to

advanced. For instance, at the primitive end of the

scale, the components in an incendiary device

employed in an attack on the American Cultural

Center in South Korea in February 1988 included a

plastic container, a desk clock, 9-volt batteries, and

a chemical substance.

sGBusiness R&S International annual reports, 1970-1989.

sTS~te r)ep~ent Statistics provided by the Oftlce of the Coordinator fOr Comteflenofism.

38see J~es p. Woottew c~Terrori~t ~cidents ~volv~g us. Citi=ns or property 1981-1989: A chrono@y,” CRS Issue Brief, Aug. 11, 1989.

s~id.s= alSO footnote 17.

~~omation for these cases are derived from a variety of sources such as those cited in footnote 8, 17, ~d19.

292-884 0 - 91 -- 2 : QL 3
26 ● Technology Against Terrorism: The Federal Effort

Figure 3-2-Geographical Distribution of Terrorist Attacks Against

U.S. Citizens and Interests, 1970-79

.

100 Attacks

&

SOURCE: U.S. Department of State, 1990.

L

Such primitive devices, however, are increasingly

being replaced by high-explosive bombs, often

utilizing SEMTEX, a high explosive of Czechoslovak manufacture, or PETN, or other plastic explosives,41 as starkly demonstrated in the downing of

Pan Am 103 over Scotland in December 1988.

Although current remote and timed detonator technology has advanced beyond the capability of some

terrorist groups, many others have demonstrated the

know-how to utilize sophisticated electronics to this 1. end. Moreover, the probability is that more and more

terrorist groups, both independent subnational and

state-sponsored agents, will be employing sophisticated electronics in the near future.

\Q +(-&

a ‘v (?

It is also important to guard against the possibility

of terrorists using such levels of technical capability

in the near future, but in the realm of chemical or

biological weapons rather than explosives and

timers. 2.

Perpetrators and Capabilities

Since the late 1960s, hundreds of subnational

groups, acting independently or as proxies of state

sponsors, have targeted the United States throughout 3.

the world. Some groups emerged for single-issue

concerns such as the Frente de Liberation National

de Vietnam del Sur in Argentina. Most of these are

now defunct. Others, with broader goals, such as the

Red Brigades of Italy, are still operational, though

weakened.

The following is a selection of terrorist groups

that have been active in recent years and have

attacked U.S. citizens and interests:42

Latin America: Fuerza Zarate Willca (Bolivia); Simon Bolivar Command (Bolivia);

Manuel Rodriguez Patriotic Front (Chile);

M-19 (Colombia); Farabundo Marti National

Liberation Forces (El Salvador); Guerrilla

Army of the Poor (Guatemala); Shining Path

(Peru); the Nicaraguan Contras; and unidentified elements within the military or security

forces of El Salvador.

Europe: Red Army Faction (Federal Republic

of Germany); Direct Action (France); Red

Brigades (Italy); November 17 Organization

(Greece); ETA or Basque Homeland and

Liberty (Spain).

The Middle East: Al Daawa (Iran); Palestine

Liberation Front (operating against Israel from

dlsee ch. 4 for a discussion of types Of explosives.

dzsee foo~otes 17 and 19 for sowes. See also Janke, op. cit., footnote 14, and DegenhardL op. cit., footnote 14 for detils on most of ~ese

organizations.
Chapter 3--The Terrorist Threat . 27

Figure 3-3-Geographical Distribution of Terrorist Attacks Against

U.S. Citizens and Interests, 1980-89

4.

a100 Attack s

SOURCE: U.S. Department of State, 1990.

bases in the Middle East); Hizbollah (Lebanon); Islamic Jihad Organization (Lebanon);

Popular Front for the Liberation of PalestineGeneral Command (Syria); Abu Nidal Organization (Libya); Abu Ibrahim (15 May) Organization (Iraq).

Asia: Japanese Red Army (Japan); New People’s Army (Philippines).

Terrorist groups often seek each other’s support.

For example, the PLO, through its affiliate members,

such as Fatah, the Popular Front for the Liberation

of Palestine (PFLP), the Democratic Front for the

Liberation of Palestine (DFLP), Sa’iqa, and the

Palestine Liberation Front (PLF), collaborated with

numerous non-Arab groups, including the German

Baader-Meinhof Group, the Italian Red Brigades,

the Provisional Irish Republican Army, and the

Japanese Red Army.

Individual members of the PLO have also been

linked with Arab and non-Arab states. Thus, the PLF

(headed by Abu’1 Abbas, who masterminded the

1985 attack on the Achille Lauro cruise ship, in

which Leon Klinghoffer, an American citizen, was

murdered) has received aid from Libya and Iraq.

And the Fatah established a strong link with the

communist bloc in an effort to create a vast

infrastructure for undertaking

throughout the world.

‘Y (?

terrorist activities

The latest shift in PLO policies, as expressed in

the December 1988 renunciation of terrorism and the

recognition of Israel, does not assure a complete

disintegration of this network as long as forces

opposed to PLO leader Yassir Arafat are committed

to the “armed struggle” strategy. The recent abortive attack (which aimed at civilian targets) on

Israeli beaches by Abu’l Abbas’ Palestine Liberation

Front provides a clear example of the persistence of

terrorism from this quarter.43

The Hizbollah (also known by other names, such

as Islamic Jihad), supported primarily by Iran, also

maintains some ties with Syria, Libya, and the PLO.

It has been responsible for some of the most

spectacular terrorist attacks, including the bombing

of the U.S. Marine barracks in Beirut in 1983, the

hijackings of TWA 847 in 1985, and the kidnapping

of most of the U.S. hostages in Lebanon.

The informal and formal relationship among

various anti-U.S. terrorist groups and state sponsors

has resulted in a machinery for terror on national,

regional, and global levels. This framework has

operated in many ways: ideological alliances, propaganda support, diplomatic assistance, geographic

43c&e, for ~xmple, yo~ ~exander ad J~sh~a s~,Te~orism: The PLO Connection (New York NY: Crane RUSS* 1989).
28 ● Technology Against Terrorism: The Federal Effort

sanctuary, financial help, training, organizational

assistance, intelligence, weapons supply, and operations. 44

A multitude of subnational groups and state

sponsors have both the motivations and capabilities

to continue to strike at U.S. interests abroad in the

foreseeable future. In addition, the possibility also

exists that foreign terrorist groups may try to attack

U.S. interests even on U.S. soil, looking for targets

that are among the less well defended. What is a

particularly disturbing development is the trend

in the instruments of terrorist warfare—from

primitive arsenals into high-technology conventional and perhaps ultimately even unconventional (i.e., chemical, biological, or radiological)

weaponry.

OBSERVATIONS AND

CONCLUSION S

In light of the record of the past two decades, the

following observations and conclusions are offered:

First, terrorism poses a variety of threats to

contemporary society. It has had a substantial impact

on the way Americans live, work, and travel abroad.

There is also an effect on the way Americans live at

home. If there are attacks on U.S. soil (if, e.g.,

Kikumura had not been arrested by an observant

State trooper on the New Jersey Turnpike and had

succeeded in bombing populated sites in Manhattan), impacts will be far greater, particularly on the

U.S. psyche.

Second, terrorism has become an integral part of

the struggle-for-power process as a form of surrogate

warfare, whereby small groups, with direct and

indirect state support, are able to conduct political

warfare at the national level, and ultimately may

even succeed in altering the balance of power on an

international level through, for example, the control

of strategic resources in the Third World.

Third, terrorists operating today are better organized, more professional and better equipped than

their predecessors of the past two decades. In the

1990s, it appears likely that they will be prepared to

undertake greater operational risks. There is a very

real possibility of attacks using chemical or

biological weapons of mass destruction in the

near future. This is of special concern since the

technology does not require a high level of

education or training, and, in fact, such capabilities are possessed by a number of countries that

sponsor terrorist activities.

Fourth, a proliferation of subnational groups will

continue to seek ideologically-based or single-issue

goals. Their attacks in the future will be characterized by both continuity and change. Groups that

are small and unsophisticated can be expected to

continue to rely mostly on bombings. Those with

enhanced skills and an international network will

carry out more complex operations, such as

kidnappings, assassinations, and attacks on facilities closely associated with governments or

companies whose policies the terrorists oppose.

Fifth, a few of the more sophisticated terrorist

groups will use increasingly high-leverage tactics to

achieve massive disruption or political turmoil.

Extremists will continue to operate as proxies or

surrogates for particular governments such as Iran,

Libya, and Syria. The techniques used will include

more and more sophisticated technologies, particularly in the area of electronics, such as those used to

provide sophisticated initiators, including remotecontrolled ones, for bombs.

Sixth, as some targets become more difficult for

terrorists to attack, we can expect terrorist

countermeasures to try to overcome added security systems as well as a redirection of effort

towards less secure targets. For example, there

may be attempts to use surface-to-air missiles to

attack aircraft when other means become too difficult to accomplish. Another possibility, again, could

be the use of chemical or biological weapons.

Seventh, there are no simplistic or complete

solutions to the dangers of terrorism. As the tactics

utilized to challenge the authority of the state are and

continue to be novel, so, too, must be the response

by the instruments of the state. We must also be

cautious to avoid the kinds of overreaction that could

lead to repression and the ultimate weakening of the

democratic institutions that we seek to protect.

Eighth, having achieved considerable tactical

success during the 1970s and 1980s, terrorists

sometimes find it politically expedient to restrain the

level of political violence. These self-imposed

restraints will not persist indefinitely, and future

~See Te~o~”st Groups profiles, op.cit., footnote 7, and Patterns of Global Terrorism, op.cit., foo~ote 8.
Chapter 3--The Terrorist Threat ● 29

incidents may continue to be costly in terms of

human lives and property. Certain conditions, such

as religious extremism or perceptions that the

“cause” is lost, could provide terrorists with an

incentive to escalate their attacks dramatically.

And finally, the vulnerability of modern society

and its infrastructure, coupled with the opportunities

for the utilization of sophisticated high-leverage

conventional and unconventional weaponry, requires the United States both unilaterally and in

concert with other like-minded nations to develop

credible response capabilities, including the creation of adequate technological tools to minimize

future threats.45

45FoI a discussion of a particular case of vulnerability, that of U.S. domestic power grids, see U.S. Congress, Oftlce of Technology Assessment

Physical Vulnerability of Electric Systems to Natural Disasters and Sabotage, OTA-E-453 (Washington, DC: U.S. Government Printing Office, June

1990).
Chapter 4

Research and Development

INTRODUCTION

This chapter provides an overview of current

research and development in technologies relevant

to counterterrorism. The technologies are divided

into

s

●

●

●

●

several fields:

detection of explosives and other weapons;

detection of and protection against chemical

and biological agents;

physical protection (e.g., alarms, barriers, access control);

incident response; and

data dissemination.

Each of these functions is briefly discussed in this

introduction and is detailed at greater length later in

the appropriate section of this chapter.

Explosives Detection

One of the most important types of detector is the

explosives detector, of great utility not only for

airline security but also for the protection of fixed

facilities, such as embassies, nuclear plants, or other

sensitive buildings. The last 2 years have witnessed

significant progress in explosives detection, both in

commercially available (or nearly available) products and in R&D efforts. Another type of detector is

the weapon detector, usually thought of as a metal

detector (although this perception may change if

other, nonmetallic weapons become available in the

future). This report will not address weapon detection, which will be taken up in the final report of this

assessment.

Explosives detector designs are based on a number

of physical, chemical, and mechanical properties.

One class of detectors is the “bulk’ detector, which

measures some of the physical or chemical properties of the object to be examined. Some detectors

employ ionizing radiation to accomplish this: examples are detectors utilizing x rays, garoma rays,

l 

or

neutrons. Radiation is used to penetrate the object

and the detector measures the outgoing radiation,

which contains information on the details of the

contents. This type of detector is limited in that,

although it can be used on baggage, it cannot be

applied to people because of the harmful effects of

ionizing radiation at the intensities required by the

widely available techniques. Recent progress in

imaging objects using ‘‘microdoses’ of x rays may

change

l

is assessment. However, even if it could be

rigorous y shown that human exposure to microdose

equipment would have negligible health effects,

there would still be a severe problem in overcoming

public skepticism toward the use of this type of

equipment.

Another type of bulk detector uses nonionizing

electromagnetic (EM) radiation in the form of radio

waves. This includes high-resolution millimeterwave radars that can search baggage or clothing for

objects, such as explosives, that would scatter the

microwaves. Also included are nuclear magnetic

resonance (NMR) and nuclear quadruple resonance

(NQR) spectrometers. These devices expose the

volume to be searched to a pulsed radiofrequency

EM field and then “listen” for pulse echoes

characteristic of particular explosive compounds.

Such detectors might be useful for consensual

searches of persons for concealed explosives if the

EM fields employed are sufficiently weak.

The vapor detector, or “sniffer,” is a different

class of detector. In this type of device, air samples

are taken and examined by rapid chemical analysis

techniques for the presence of molecules of explosive compounds. This class of detectors may well be

used to search people as well as baggage.

The original vapor-based explosives detector is,

of course, the dog, which is very effective for some

purposes, but which has some serious “canine

factors” limitations. Dogs, while very sensitive

detectors, have limited attention spans, must be

integrated as a team with a particular trainer to be

most effective (thus generating high operating

costs), and are often not consistent from day to day.

They are still the best explosives detectors available

for a wide variety of uses, such as a sweep of a

well-defined area in the wake of a bomb threat.

However, for many purposes, such as routine

IGaroma rays are, like x rays, elec~magnetic radiation characterized by very short wavelengths, but unlike x rays, they are generated by nuclear,

rather than atomic interactions. Gamma- ray wavelengths are generally shorter (equivalently, of higher energy) than x-ray wavelengths, but there is an

overlap between the two types.

–31–
32 ● Technology Against Terrorism: The Federal Effort

baggage inspection on airlines, dogs are not appropriate.

A host of factors, such as temperature, soak time

(time between the placement of the bomb in the

container and the attempted detection), amount of

ventilation, and operator expertise, dramatically

affect the performance of sniffers. Defining uniform,

consistent, and realistic threat scenarios is critical to

the development of minimum performance standards and objective evaluation criteria for vapor

detectors.

Remote (or, in military jargon, “stand-off”)

detection of vapors is quite a challenging task. It

could be particularly useful for examining, at a

distance, vehicles suspected of containing a large

amount of explosives. A laser beam, tuned to the

correct wavelength, can be used to stimulate the

molecules of a particular species of chemical vapor,

for example, an explosive. These molecules then

may absorb or emit light at well-defined wavelengths. These phenomena could form the basis of a

remote detection scheme. The characteristic wavelengths of explosive chemical compounds would

have to be systematically measured to provide a

database for the detector. This type of technology is

being developed for the detection of chemical

warfare agents (see app. D). However, a relatively

large amount of vapor would be needed in order to

make explosives detection feasible. While the potential theoretically exists for applying this technology

to the remote detection of explosives, small bombs

in suitcases would not likely be easily detectable

unless observed at very short range. However, there

are other cases in which remote detection by laser

absorption or excitation might be a possibility.

Another explosives detection mission, for different scenarios, is to look for buried explosives. Work

is proceeding on the development of groundpenetrating radar that could find buried objects. This

capability would have useful applications for a

number of counterterrorist tasks, from finding buried

arms caches to detecting mines.

Chemical and Biological Agents

A terrorist attack using chemical or biological

(CB) agents has not yet occurred, but might happen

in the near future (see ch. 3). The fact that such

attacks have not yet taken place at a serious level (in

a terrorist context) may explain the low priority

given to efforts to analyze and deal with such

eventualities. One exception to the general low

priority given to this topic is the work undertaken by

the interagency Technical Support Working Group

(TSWG).

Sometimes referred to as “poor man’s atom

bombs,’ chemical or biological munitions require

far less technical sophistication than nuclear weapons. However, they, too, can qualify as weapons of

mass destruction. It should be noted that classical

chemical munitions and delivery technology were

used effectively in World War I, some 75 years ago,

and were further developed by several nations by the

time of World War II. Some biological weapons

technology is available, in principle, to any nation

that can brew beer. Chemical or biological agents

could be ideal for attacking targets such as embassies, perhaps through water or air supply systems.

Defense against terrorist CB attacks requires a

combination of early detection and diagnosis, evacuation of endangered individuals, appropriate vaccines for preventing spread of infectious agents,

antibiotics and antidotes for treatment, means of

protection, and decontamination. An important element of defense against CB attack would be the

ability to learn rapidly of the approach of such

agents, either through air or water. Laser-based

systems show some promise for early detection.

Other areas of interest lie in the development of

portable or miniaturized means of protection. There

is some, but not much, activity in this area in the

Federal sector. Some attempts to develop detection

and protective capabilities applicable to terrorism

have been made, notably by the TSWG.

Physical Protection

Physical protection includes the timely detection

of attacks, delays forced on attackers (including

armor and hardening of targets), and the response to

attacks.2 This section discusses alarms, barriers,

access control to sensitive areas, blast protection,

and hardening against projectiles. Detection and

response are covered in other sections.

For example, physical protection for commercial

airline security can include access control, applied

zSan&a Natio~ ~boratories, Designing the Physical Protection System, vol. II of Physical Protection of Nuclear Facilities ati Mate~”ak, me

Ninth Intermtional Training Course (Albuquerque, NM: Sandia National Laboratones, 1989).
-.

Chapter 4--Research and Development 33

both to passengers and site workers (this could

amount to as little as a few locked doors with a

security force able to respond rapidly); metal detectors; and, possibly, explosives detectors. A fully

integrated system would also include perimeter

design; division of the airport into different security

areas, each with its own access control; closed

circuit TV; various types of alarms; and barriers. In

addition, aircraft could be modified or retrofitted to

mitigate the effects of inflight explosion. Finally,

human factors technology and related psychological

research data could be employed, along with the

mechanical components and defined system procedures.

General fixed-site security includes incorporating

resistance to explosive blasts in architecture and

engineering design, stand-off pedestrian barriers,

and well-designed vehicle barriers. Further, as with

airports, entrance procedures and access control for

the public and on-site workers can present obstacles

to a terrorist trying to introduce explosives into a

building. In addition, external and internal barriers

and protection devices are options for preventing

overt assaults on a building.

Incident Response

Incident response covers those technologies useful in dealing with hostage-taking, an assault on a

freed site, or other criminal undertakings that maybe

interrupted by appropriate response force actions.

Incident response includes disruption of the attack;

defending targets, where possible; aiding the injured; protecting or evacuating those endangered;

rescuing hostages; and apprehending the attackers.

Coordinating different response forces (which may

be from different agencies for a domestic incident or

from different countries for an international case) is

a key aspect of incident response.

There are many areas where technology or social

science can help resolve the problem. For example,

in some scenarios, pre-positioned sensors would be

helpful in aiding rescue attempts. Human factors

techniques, particularly applied to hostage negotiations, are vital in dealing with ongoing terrorist

incidents. And software, ranging from checklists to

sophisticated decision aides, would help. Incapacitating agents, riot control agents, or weapons that

disable but do not permanently damage exposed

individuals, might be of use in some cases. Possible

techniques might involve chemical agents or exotic

weapons using other physical principles.

The development of technology to aid various

incident response tasks will be discussed in greater

detail in the final report of this assessment.

Data Dissemination

Institutional and, occasionally, legal barriers prevent the free flow of information among Federal

agencies, and among Federal, State and local law

enforcement officials. This difficulty applies even

where terrorist threats and time-critical information

on terrorist activities are concerned. There are also

some technical barriers to the rapid and secure

diffusion of such information. On another level, it

appears that even up-to-date R&D information is not

always easily available to agencies that need it.

Resolving this problem often requires modifying the

behavior of institutions, although some technical

developments could be useful in mitigating the situation.

This chapter deals with all of the above issues. In

general, the information contained is not exhaustive,

but provides an overview of the relevant technical

work underway, along with an estimate of how near

to field deployment the more promising technologies are. More details will be provided in the

comprehensive final report of this study.

DETECTING EXPLOSIVES

Introduction

The detection of small quantities of explosives is

often difficult but is by no means impossible.

Advanced nuclear techniques and vapor detectors,

as well as those based on other principles, have been

refined to a point where simple detection is no longer

the key issue: the question is rather whether the

stringent demands of many applications can be met.

For example, there are several difficulties related

to explosives detection for protecting commercial

aviation. First, for screening baggage, the rate and

volume of the load to be processed are daunting.

U.S. airlines handle close to a billion pieces of

baggage a year, and U.S. passenger traffic is over 40

percent of the total world volume. Therefore, the

detection system must have a high throughput. The

Federal Aviation Administration (FAA) requires a

minimum rate of 600 bags/hour (6 seconds/bag) for

an explosives detection system, but airlines would
34 ● Technology Against Terrorism: The Federal Effort

like a screening rate at twice that speed for a given

flight (a Boeing 747 typically ingests approximately

700 to 800 pieces of checked luggage). The ideal

placement of a detection system for checked luggage

would be at the check-in counter, where the passenger and bag are together, and where significantly

more than 6 to 12 seconds are needed anyway for

ticket processing.

Second, the threat is so diffuse. In 1989, only six

baggage bombs were placed aboard aircraft (unless

there were others that went undetected). It is not

currently possible to err on the safe side by increasing detector sensitivity because too many false

alarms would result, and the delays involved in

resolving them would snarl the whole air traffic

system.

Finally, many believe that explosives detection

equipment must be automated (i.e., the decision to

select a suspicious bag for further investigation is

performed without human intervention), because

inspecting many pieces is a repetitive and boring

task of which humans (and even dogs) quickly tire,

becoming inefficient. Still, in the end, the effectiveness of even the most highly automated security

system will depend on the training and motivation of

human beings-those individuals who perform further investigations.

While airline security involves searches of handheld bags or packages, checked baggage, mail, and

materials carried by individuals, other applications

for explosives detection have different requirements. Inspection of vehicles, as well as packages or

cargo, is a prime concern for other secure locations,

such as U.S. embassies abroad. Searches must be

rapid, cost effective, noninvasive, and nondestructive. There are a variety of techniques that can meet

at least some of these criteria for some types of

searches and produce a usable signal when encountering explosives.

Many techniques utilize ionizing radiation that

penetrates the item to be searched. The radiation

interacts with the nuclei of the examined object to

produce absorption, secondary radiation, or both.

These effects are then detected. Recent attention has

focused on detection of nitrogen nuclei through

nuclear techniques: nitrogen is found in high proportion in most explosives. There are various advanced

versions of the common airport x-ray systems, as

well as some chemical sniffers, each of which has

specific capabilities and shortcomings. There are

also techniques being investigated that utilize laser

detection, infrared radiation, ultrasound, microwaves, and other methods that are not yet sufficiently developed to evaluate realistically.

This raises an important factor that differentiates

among detection concepts: the relative state of their

development. Experimental measurements have

been made for a large number of different concepts.

Laboratory systems based on some of these concepts

have been used to demonstrate feasibility. A still

smaller number have advanced to the prototype

stage and have undergone actual airport experience.

There are also some devices that are modifications

of commercially available hardware systems and

have new capabilities. Each of these categories must

be viewed from a different vantage point with

respect to their utility for the detection problem.

In general, devices that are in the research stage

will be 5 to 10 years away from commercial availability, especially if they are based on new, complex

technology. Worse yet, even this sluggish pace is

premised on the assumption that adequate levels of

federal support are forthcoming. A 2- to 3-year

period may be expected for a successful research

phase; a feasibility demonstration may well take 2

more years; a prototype program can easily last 2 to

3 more years; and, finally, any test at a customer site

can take another 2 years.3 Consequently, the status

of each development program must be looked at

carefully to assess where the concept stands in the

development cycle. Hardware based on modifications of previously utilized products, which is

sometimes possible with devices or systems used in

other industries for other purposes, may shorten this

cycle. As a rule, the simpler the device, the shorter

the development time.

The Explosive Threat

There are literally hundreds of different types of

explosives, varying from black powder used in pipe

bombs (still a favorite of domestic bombers), to

dynamite sticks, and from blocks of TNT to plastic

explosives that can be molded into diverse forms,

including thin sheets. A dozen or so of the most

notable explosives, including most of those used by

3For example, the current thermal neutron analysis (TNA) technology is approximately 10 years old, with early research at Westinghouse Pr*t~g

the 1985-90 Scientific Applications International Corp. (SAIC) TNA program.
Chapter 4--Research and Development ● 35

terrorists, are described in table 4-1. Of particular

note are the explosives RDX and PETN which,

together with

many plastic

SEMTEX.

plastic and other fillers, compose

explosives such as Detasheet and

History

Efforts to detect explosive materials have been

ongoing for many years. Before applications for

airline security were considered important, other

applications (e.g., military security, security at

nuclear weapons and nuclear power plants, security

at the U.K. Houses of Parliament) stimulated interest

in the development of explosives detection techniques. The use of dogs to sniff explosives has been

common for over a decade, but there has been a

simultaneous desire in the law enforcement community to find technical means of doing what dogs can

do, doing it better, and doing it more consistently

without the difficulties arising from canine factors,

such as boredom, distraction, chemical maskers,

mood, etc. Dogs as sniffers will be discussed further

in the final report.

In general, detection techniques can be divided

into two main categories: vapor detectors (relying on

accurate identification of trace airborne samples of

explosives) and bulk detectors (relying on an interaction between some kind of penetrating radiation

and the hidden explosive). A list of various types of

explosives detection strategies is presented in table

4-2 and a more detailed discussion is provided both

later in this chapter and in appendixes A through C.

A brief history of the development of these applications is presented below.

The first noncanine explosives detector, designed

to sense dynamite vapor, was developed in the early

1970s by Analytical Instruments of the United

Kingdom and its affiliate, Ion Track Instruments of

Burlington, MA. In the two decades since then,

progress has been great, and many competing

techniques have been developed.

Interest in applying explosive vapor detectors to

protecting commercial aviation increased after several terrorist incidents in the early 1980s, and FAA

began sponsoring more research into sniffers in

1982. In 1984, the FAA funded Thermedics, Inc. of

Woburn, MA to develop vapor detection technology

in a direction that could prove useful for airport

security. This work was aimed at producing a

walk-through portal monitor. In 1986, the State

Department also funded work at Thermedics to

develop similar technology to detect explosives in

packages. Earlier sniffer technologies were able to

detect only those explosives with higher vapor

pressures (1 to 100 parts per million), such as

dynamite and nitroglycerine. Some manufacturers

now claim that their products have been refined to

the point where it is possible to detect TNT under

realistic conditions. However, at least until recently,

plastic explosives, which have far lower vapor

pressures (as low as parts per trillion), were beyond

detection by vapor means under conditions that

would prevail in the field (i.e., at security portals or

in airports). This situation has changed.

Researchers realized that detection of low vapor

pressure explosives by sniffing techniques would be

extremely difficult. Therefore, the FAA also funded

efforts in researching nuclear techniques of detection, beginning with Westinghouse in the late 1970s

and then, in 1985, also with a contract to Science

Applications International Corp. (SAIC). This latter

work led to the development of the Thermal Neutron

Analysis (TNA) device that is currently the subject

of much interest and controversy. The principal

contract with SAIC on TNA was concluded in 1987

and 1988 with a series of ‘acceptance’ tests at the

San Francisco and Los Angeles airports; SAIC was

then awarded a contract to build five (later increased

to six) TNA machines for installation and testing at

various airports.

The TNA device is intended only for inspection of

checked baggage, since it involves irradiating a test

object with an intense “bath” of neutrons. In

principle, it could also be applied to carry-on

baggage, but, so far, cost and size problems, already

a serious difficulty for the checked baggage application, have been cited as arguments against utilizing

TNA for inspecting hand-carried baggage. In at least

one foreign country, however, the feasibility of

using smaller, less accurate, but cheaper TNA

devices for this purpose is being explored.4

The problem of developing useful explosives

detectors for commercial aviation security has increased in urgency and political visibility in the

4SiII@ c~+n bags USually have less mass than checked baggage, it should be easier for a bulk detector, such as TNA, to see a small explOSive in

a carry-on item amidst the background generated by the rest of the luggage.
36 ● Technology Against Terrorism: The Federal Effort

Table 4-l—Some Common Explosivesa

TRADE OF POPULAR CHEMICAL NAME, FORMULA, COMMENTS

NAME(S) AND STRUCTURE

AN, Ammo-Nite Ammonium nitrate

(NHJ (N03)-

Black powder

Composition B

Dynamite

EGDN

HMX,

Octogen

Nitrocellulose,

gun cottonb

Ethylene glycol

H2C– ONO2

H2C– ON02

dinitrate

Cyclotetra-methylene tetranitramine;

1,3,5,7-Tetranit ro-1 ,3,5,7-

tetrazacyclooctane

N 02

I

N — C H2

/ \

CHZ N— NOZ

I

OZN — N CHP

\

C H2— N

/

N 02

0 2N 0 O N 02

I I — iH C[ CH —.

\ 7H 0

CH o

I

CHZ — ONOZ

Also commonly used as a fertilizer. Frequently

mixed with fuel oil to make explosive called

ANFO.

Mixture of potassium or sodium nitrate, sulfur,

and charcoal. Explosive most commonly used

in terrorist bombs in the United States.

60:40:1 mixture of RDX:TNT:wax

Compositions have varied over the years. The

explosive components of modern dynamites are

principally EGDN and NG absorbed onto

combustible pulp (e.g., wood meal, starch, rye

f I our),

One of the main components of dynamite.

Quite volatile, making detection by “sniffers”

relatively easy.

A military plastic explosive.

Main component of smokeless powder.

n
Chapter 4--Research and Development ● 37

NG

Nitroglycerine

PETN

Picric Acid

RDX,

Research Division X,

Formula X, Cyclonite

Hexogen

SEMTEX

Table 4-1--Some Common Explosivesa--Continued

Glycerol trinitrate

H#-0N02

H! CONOZ

HZC– ON02

Pentaerythritol tetranitrate

0 2 NOC H2 — C- CHZON02

Trinitrophenol

OH

02N

o

\

N02

/

N02

A plastic explosive available in bulk form or,

with modifications, in sheet form under tradename

“Detasheet.”

Unusually low nitrogen density for a plastic

explosive: 18 percent by weight (compare with RDX).

Cyclotrimethylenetrinitramine; Primary ingredient of military plastic explosives

1,3,5-Trinitro-l ,3,5-triazacyclohexane known as C-3 and C-4. 38 percent nitrogen by weight.

N02

I

/ N \

C H2 CHZ

I I o2N”N\ /N~N02

CHZ

A Czechoslovakian-made explosive composed of

a mixture of varying proportions of RDX and

PETN along with binder and plasticizer.
38 ● Technology Against Terrorism: The Federal Effort

Tetryl, Tetralite

TNT

Table 4-l-Some Common Explosivesa--Continued

2,4,6, N-Tetranitro-N-methylanaline; Most common military booster.

2,4,6-TrinitrophenyI-methyl nitramine

CH3 N02

\#

02N&‘ N02

y

N02

Trinitrotoluene A castable explosive.

CH3

02N

N02

NOTES:

wake of the Lockerbie crash, in December 1988.

There had been previous bombings of aircraft, but

most attacks on U.S. airliners, although causing

some fatalities, had not brought down an aircraft.

There had been several bombings that had destroyed

non-U.S. commercial aircraft, the best known being

the 1985 bombing on an Air India flight from

Montreal to London, in which 329 were killed.

However, none of these had the impact on the

American public and Congress that the Lockerbie

crash did. Table 4-3 shows major commercial

aircraft bombings since 1980.

Following Lockerbie severe pressure was brought

on the U.S. Government to take immediate action to

prevent repetitions of this tragedy. The FAA, by

virtue of its responsibilities and mission, bore the

brunt of criticism and pressure for action. In

addition, the media, some elected officials, and

various private groups, such as the Victims of Pan

Am 103, expressed the opinion that information

constituting a sufficiently specific prior warning had

been made available to some personnel in government agencies, while being concealed from the

traveling public. This resulted in much public

criticism of both the FAA and the Department of

State.

Methods of Explosives Detection

All detection techniques depend on sensing properties that are shared by explosive compounds and

are relatively unique to them. Fortunately, there are

several physical, nuclear, and chemical characteristics of common explosives that are helpful to this

end. Unfortunately, these compounds also share

properties that make their detection difficult. The

challenge to the designers of detection equipment is

to create a system that can make use of the helpful

properties and compensate for those that cause

difficulties.
Chapter 4--Research and Development ● 39

Table 4-2—Explosives Detection Technologies

Bulk detectors:

Using ionizing radiation

Nuclear

—Thermal Neutron Analysis

—Fast Neutron Analysis

—Nuclear Resonance Absorption of Gamma Rays

—Associated Particle Production

—Pulsed Fast Neutron Analysis

—Pulsed Fast Neutron Backscatter

-Nitrogen-1 3 Production with Positron Emission

Tomography

X-ray

—Transmission

-Backscatter

—Dual- or Multi-Energy

-Computerized Tomography

Using non-ionizing radiation

Nuclear Magnetic Resonance

Electron Spin Resonance

Nuclear Quadrupole Resonance

Vapor or residue detectors:

Dogs

Gas Chromatography (GC)/Chemiluminescence

GC/Electron Capture

Ion Mobility Spectrometry

Mass Spectrometry (two-stage)

Bioluminescence

SOURCE: Office of Technology Assessment, 1991.

The characteristics generally common to explosive

●

●

●

●

●

●

●

●

●

compounds are:

high nitrogen content and nitrogen density;

the frequent presence of nitrogen as a nitro

(-NO2

) group;

high oxygen content, low carbon and hydrogen

content;

relatively high density (about 1.5 times the

density of water);

extremely low vapor pressure;5

high polarity (also called electronegativity);6

low thermal stability;7

frangibility; 8 and

adsorptivity.

Some nonexplosive materials have similar densities or percentage nitrogen content, but only a very

small subset of materials has the high nitrogen

density of explosives. Almost no nonexplosive

materials have both the high nitrogen and oxygen

densities that characterize most explosives.9 A

system that could reliably measure the nitrogen

density distribution in a bag with good spatial

resolution (probably one or two centimeters in each

dimension or better), should be able to detect most

explosives with few false alarms. One that could

measure the distribution of nitrogen, oxygen, and

carbon within a bag should provide detection with

almost no false alarms.

Figures 4-1 through 4-4 illustrate this. Density

alone, which is what the simple x-ray scanner

measures, does not distinguish explosives from

plastics and other common materials (see figure

4-l). Because certain fabrics contain a large weight

fraction of nitrogen, the fraction of a bag’s contents

that is nitrogen is also not a good indicator of

explosives (see figure 4-2). However, figure 4-3

shows that if the nitrogen density distribution can be

measured locally within a bag, then only a very few

materials will mimic explosives. Unfortunately,

among these materials are melamine, leather, and

solid nylon, none of which is particularly rare. These

substances can cause false alarms if only nitrogen

density is measured. Figure 4-4 shows how explosives could be identified uniquely by adding an

oxygen measurement. Explosive detectors using

nuclear techniques all utilize the above hierarchy of

phenomena.

Nuclear Methods of Explosives Detection

One family of explosives detection devices depends on ionizing radiation, such as neutrons or

high-energy photons (gamma or x rays), to penetrate

the object to be inspected. The interaction of these

penetrating types of radiation with the elements in

the luggage produces signatures that can identify an

explosive: the degree of uniqueness depends on the

particular technique. The level of specificity of the

5~ ~ lmge ~omt of liq~d or ~~lid is pl~~~ ~ a ~lose.d con~er, the ~t~ will evapo~te UII~ WI ~lditium (dSo kIIOWll aS SahKdiOIl) h

established. Thereafter, the rate at which molecules escape into the gas phase will be equal to the rate at which molecules in the gas phase return to the

condensed phase. The pressure generated by the gas phase molecules under these conditions is characteristic of the material and varies only with

temperature. The more reluctant a substance is to evaporate, the lower tbe vapor pressure.

6Even ~ou~ a molec~e my ~, ovm~, elec~c~y neu~~, atom or ~oups of atoms wi~tie molecule may be electidly polti~d ~d have

the power to attract electrons. This is called electronegativity. The -NOZ groups typic~ of modem explosives possess ~s ProW~.

7This meatittie molecules easily breakup when their temperature is raised.

8Fr@bili~ is tie tendency of a mol~tie to break apart when it SldCeS Or iS hit by ano~er obj=t.

%ere area few non-nitrogen-based explosives, such as perchlorates. These, however, are relatively unstable and run the danger of exploding when

the terrorist would rather they did not. To date, these have not been widely used in attacks on aircraft although there is the possibility that if authorities

were able to detect the nitrogen-based compounds, terrorists might turn to some of them.
40 ● Technology Against Terrorism: The Federal Effort

Table 4-3--Airline Crashes Caused by Terrorist Bombs, 1982-89

Date Airline/aircraft type Route Deaths

September 1983 Gulf Air/737 Karachi to Abu Dhabi 112

June 1985 Air lndia/747 Montreal to London 329

November 1987 Korean Airlines/707 Baghdad to Seoul 115

March 1988 BOP Air (South Africa)/ Phalaborwa to Johannesburg, South

Bandeirante Africa 17

December 1988 Pan Am/747 London to New York 270

September 1989 UTA/DC-10 Ndjamena, Chad to Paris 171

November 1989 Avianca/727 Bogota to Cali 101

SOURCE: Federal Aviation Adminietration, The Washington Post Counter-Terrorism and Sewity Intelligence, Report

of the President’s Commission on Aidine SeoMtyand Twrotism, 1990.

identification is an inherent limitation on the usefulness of the concept. Other limits are the level of

engineering development and the projected cost.

The net utility of each method depends on its

statistical probability of detecting hidden explosives

of all sorts and on its potential for false alarms,

which must be kept at a very low level (preferably

less than 5 percent) to avoid disruption of normal

operations.

TNA is unquestionably the most advanced of the

current generation of Explosives Detection Systems

(EDS), and, by virtue of the experience being gained

at various airports, will also be the most tested.

Nevertheless, the current SAIC TNA system, the

only operational one, is, at best, a marginal EDS. It

measures the presence of nitrogen by means of the

interaction of thermalized neutrons (from a radioactive californium source) with the nitrogen nuclei.

This interaction produces high-energy gamma radiation of a characteristic energy that is then detected.

The numbers for detection probability and falsealarm rate vary, depending on several alternative

details of the integrated detection system. Adding an

x-ray device to TNA (utilizing and correlating

information from both systems) and retrying suspect

bags both change performance. Performance also

varies with the type of baggage (defined by season,

destination, and originating airport) being inspected.

Its performance for detecting lesser quantities of

explosives is poorer: the probability of detection is

lower and the false-alarm rate higher. The FAA

arranged for an outside group of experts to retest the

SAIC TNA at more sensitive detection limits in

early May 1990. See appendix A for a discussion of

this test.

Checked baggage normally contains a wide range

of nitrogen. The problem is to identify as suspicious

only those bags with an excess of nitrogen-in an

amount corresponding to the nitrogen content of a

small plastic explosive-in the presence of this

varying background. Attempting to detect smaller

amounts of excess nitrogen would cause a large

false-alarm rate. One possibility to resolve this

problem would be to identify the location within a

bag of any nitrogen excess. The current TNA has a

limited spatial resolution, capable of giving only a

vague idea of wherein a bag a suspiciously elevated

nitrogen content is found, so its capacity for false

alarm reduction is similarly limited. If TNA were to

be applied to carry-on baggage, which usually has

less mass than checked baggage, the background

would be less and presumably the false-alarm rate

for a given detection probability would be lower.

One of the unique features of TNA is that it is an

automated system, i.e., one with no operator in the

go/no go decision process. The system has some

operational problems in that it does require significant shielding (built into the system) it is large and

heavy, and is very expensive (about $1 million

each). A more detailed discussion of the TNA

concept is given in appendix A.

Beyond TNA, there are a number of nuclear-based

systems that are in the laboratory demonstration

stage. Several hold the promise of improving on

some of TNA’s shortcomings. One avenue of

approach is to use faster neutrons, which allows the

detection of elements other than nitrogen, such as

oxygen and carbon, thus potentially reducing falsealarm rates considerably. The measurement of all

three elements simultaneously would produce an

effective and specific explosives discrimination

process, as discussed above. Both steady and pulsed

beam versions of Fast Neutron Analysis (FNA) are

under investigation. Some concepts would greatly

improve spatial resolution, as well as yield information on several elemental constituents of explosives.

More energetic neutron systems require more complex sources, such as accelerators, which are not
Chapter 4--Research and Development . 41

c

(a

,

,

,

,

I

,

,

,

,

,

,

,

,

I

,

a(j

a>

‘ns

I

-r

c-0

<

z

,

,

,

I

,

,

I

,

,

,

,

,

$

I —

—

N

o
Figure 4-2—Nitrogen Percentage of Various Materials

-1 Common plastics

+----------------------------------------------------- -------------------------------------------- ----

///~//////////H////////////~/////// A

///////////////////////////4

/////////////////////////&

I I

Clothing

---- ----- ----- . . . . . ----- -

Explosives

---- ----- ----

0 1 0 20 3 0 40 50 60

Percent nitrogen, by weight

SOURCE: L. Grodzins, 1990.
Figure 4-3—Nitrogen Density of Various Materials

k////A

A few common mater iais

._. ..-_ -__-------- .. ----- . -------------- —-------

Common plastics

F~//////////zZZ3

////////////////////////////////////////////~//////H~/////~////////////////////-

/////////// 2

------------------------------------------------------------------------

i

------------------------------------------------------------------------

-----------------------------------------

Clot h i ng,

Density of 0.2 g/cm 3

/////////2z2z%z/////

////////////////////////////A

/////////%/22//////2

Ex p Ios i ves

/////2332//////==

///////H/////////////#////////////////////HY///Y/~/////////4

/////////id/3z///// z

//////////~/////////////m

I

o 0 . 2 0 . 4 0 . 6 0 . 8 1

Density of nitrogen, in glcma

SOURCE: L. Grodzins, 1990.
44 ● Technology Against Terrorism: The Federal Effort

Figure 4-4-Correlation Between Oxygen and Nitrogen Densities in Explosives and Other Materials

c’ al

a

*

x

o

1.5 “

1.4

1.3

1.2

‘1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Sand

EXPLOSIVES

❑ PETN

❑ Nitroglycerine

Ammonium nitrate

❑

Water ❑

o ❑

Sugar

❑

Dynamite ❑

TNT

❑

❑

I ❑ Black powder

HMX

❑

C-3 o ❑ C-4

❑ Polyurethane

Cocaine

D Nylon, Solid

Silk

❑

❑ Melamine

~

I I I I I 1 I

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Density of the nitrogen, g/cm3

SOURCE: L. Grodzins, 1990,

available commercially and require development.

Such devices will probably be larger, more expensive, and require more shielding than TNA. Appendix A discusses the FNA systems.

A somewhat different approach, based on the

phenomenon of resonance absorption of garoma rays

in nitrogen, has been explored and demonstrated in

the laboratory and is now at the prototype development stage. In this approach, gamma rays (created

through the absorption of a proton beam by a carbon

target) are utilized to produce a gamma-ray absorption image that is specific to nitrogen content. The

process has fairly good spatial resolution and is

sensitive to small amounts of nitrogen, both advantages over the current TNA. However, OTA estimates that this concept is at least 3 years away from

a prototype demonstration (if fully funded) of the

sort currently being done for TNA. This approach is

also described in more detail in appendix A.

There are several other nuclear-based explosives

detection schemes, some of which are discussed in

appendix A; a few other similar ones are not specifically mentioned. These concepts are all in the

laboratory research stage.
Chapter 4--Research and Development . 45

Accelerator Technology

All nuclear techniques have a common problem in

that they require means of generating neutrons or

other energetic particles in order to produce the

penetrating radiation with which they probe objects

to be examined. All of the proposed techniques, with

the exception of the current SAIC TNA machine that

employs a radioactive californium source,10 require

some form of accelerator. Some general discussion

of accelerator technology is thus useful to emphasize

their common advantages and problems.

Although accelerator technology is a welladvanced science, work in accelerators has been

primarily in support of laboratory experiments. Both

small and very large machines are operated throughout the world, but generally by highly trained

scientists, usually physicists or electrical engineers.

An exception to this generality is in the area of

semiconductor processing and medicine, where

accelerators have been employed in industrial processes and where some success has been achieved in

reducing their complexity and their costs of operation and maintenance. Fortunately, the accelerators

needed for explosives detection are similar to those

exploited for these applications.

Accelerators have common characteristics that

complicate their use in industrial applications. First,

they are complex, highly sophisticated machines,

involving very high voltages (100,000 to 1,000,000

volts). Second, they are relatively large and take up

a significant volume. Third, many produce neutrons,

which must be stopped by shielding; further, most

materials used to attenuate or isolate these neutrons

are also activated and require their own shielding.

The higher the energy and intensities of the produced neutrons, the greater the activation and

shielding problem.

Another problem is that all accelerators require

some source of ions or electrons, and these sources

wear out. In general, the high current requirement

and prolonged continuous operation of explosives

detector applications tax the state of the art of these

sources. Finally, all accelerator concepts that have

been suggested for explosives detection will be

considerably more expensive than the isotopic

sources; accelerators would usually cost $100,000

and more.

Several different types of accelerators have been

built or tested with an eye to eventual use for

explosives detection. Early SAIC experiments for

the FAA used a sealed source produced for industrial

applications. This source was based on the D-D

reaction, i.e., it accelerated a heavy hydrogen

isotope, deuterium, to collide with a deuterium

target. This source had a very poor lifetime (of the

order of 100 hours). Later, under FAA sponsorship,

an electrostatic accelerator was built (by National

Electrostatic Corp.) and used at SAIC to replace the

Cf-252 source in the TNA. It was judged too big,

complex, and expensive ($200,000) by comparison

with the isotopic source, but it has been successfully

demonstrated as an alternative TNA source.ll

The FAA and TSWG have also sponsored the

development of another type of accelerator, the radio

frequency quadruple (RFQ), which is currently

under test by ACCSYS Technology, Inc. This

system is a development based on Los Alamos

National Laboratory technology (that had been

advanced through funding under the Strategic Defense Initiative). The system was transferred to a

small private company, which is continuing this

research via a Small Business Innovative Research

grant. Like all accelerators, the RFQ has the

advantage of being switchable (i.e., it can be turned

on and off at will). However, it is a pulsed system,

which creates some electronic problems for TNA. It

is unlikely that the RFQ accelerator can compete

with the isotope source in cost, size, or simplicity.

Nuclear systems other than TNA require more

energetic particles. Fast neutron analysis requires

energetic neutrons. These are, in practice, usually of

14 MeV energy, generated from D-T reactions (in

this case the deuterium target is replaced by a tritium

one--tritium is a radioactive isotope of hydrogen).

Although so-called electronic tubes to produce these

reactions have been available for scientific and some

industrial applications (e.g., for well-logging in the

oil industry) for years, their development for explosives detection is still in prototype testing stages

l~ec~iforfim.252 somce@in he SAIC TNA WaS a judicio~ choice horn several points of view: it is used extensively in the medid field

and in other industrial applications; it is well developed and industrially qualifix highly tested models are available; it is ve~ small compared to most

accelerators; its shielding requirements are well know and it is relatively inexpensive ($10,000 to $20,000). However, its radioactivity introduces its

own set of problems and concerns, which have been discussed.

1lw. WW, FM Techni~ Center, personal comrnticatio~ 1990.
46 ● Technology Against Terrorism: The Federal Effort

(e.g., at SODERN in France). The operating characteristics of such devices have not yet been assessed.

Such systems are being developed to support both

the continuous and pulsed version of fast neutron

analysis.

Other techniques, such as nuclear resonance absorption (NRA) of garoma rays, have special accelerator

requirements. In the NRA case, a relatively low

energy (1.75 MeV) proton beam is required. This

eases the shielding requirements because few nuclei

will be rendered radioactive by such a low energy

proton beam. However, the systems requirements,

particularly in terms of beam current (the number of

protons produced per second), do strain the state of

the art of this type of accelerator. Electrostatic

accelerators, similar to laboratory Van de Graaff

high-voltage machines, can support early NRA

experiments by extending the present currentcarrying performance of the systems and sources by

a factor of 2 to 5 (to about 0.5 milliamperes (mA)).

It is believed that a final system would require

currents beyond this capability (2 to 5 mA). Other

accelerator candidates are available, based on concepts that have been used in industrial ion implantation machines, but the development and industrialization of such accelerators has been a timeconsuming, multimillion dollar program.

Still another class of accelerator under consideration is the electron accelerator needed for the

Nitrogen-13 production concept. In this case, a

radiofrequency (RF) linear accelerator (LINAC) is

the prime candidate. Production of a 13.15 MeV RF

LINAC of sufficient current is not a great challenge

to the technology. The issue is one of size, shielding,

industrialization, and cost. From current experience,

it is not likely that such a system will be small, easy

to shield with minimal structure, or cheap.

X-Ray Technologies

Existing commercial x-ray scanners are capable

of giving high resolution images of the interior of

objects. They have been used for many years to

check hand-carried baggage and, more recently,

checked luggage. During the last 5 years, major

strides have been made in x-ray technology. New

models are far more capable than those in general

use at airports today. Some of these new systems can

now differentiate between materials composed of

light or heavy elements, and some have very good

resolution with three-dimensional imaging capability. However, so far, no x-ray system has been

automated to make autonomous decisions (in order

to satisfy FAA requirements for acceptable explosives detection systems), although several vendors

are working on such modifications. In general, x-ray

systems are under development by large- or midsized established commercial manufacturers and

these systems are modifications of their current

products. New x-ray systems can therefore be

brought to the market much more rapidly than most

of the other devices discussed earlier in this section.

The most important new developments in x-ray

systems are in the areas of dual- or multi-energy

systems, backscattered x rays, and computerized

x-ray tomography (CT). Dual- or multi-energy

systems are able to distinguish between low and high

Z (or atomic number-the number of protons in a

given nucleus) elements to a degree and can present

the viewer with two or more images that emphasize

the different materials (e.g., by color differentiation). Commercial devices with this capability are

produced by EG&G Astrophysics and SiemensHeimann.

A somewhat different approaches the Z-Technology

(a trademark), or back-scatter x-ray system developed by American Science& Engineering (AS&E).

In this case, the low Z image is created by a different

process, i.e., detection of Compton backscatter

radiation. Commercial Z-Scan systems exist and the

manufacturer is now attempting to develop an

automated pattern recognition approach that will

meet the FAA's EDS requirements. Discrimination

between high and low Z, although useful, does not

specifically and uniquely identify explosives.

Another x-ray system under development is based

on the application of medical computerized tomography (CT) technology to explosives detection.

One company, Imatron, is close to having a prototype unit on the market able to produce threedimensional images of suspicious items within a

suitcase using CT processing. Through analysis of

the data, they claim to be able to determine density

to a high degree of precision. This provides a strong

clue for detecting explosives. The demanding computing requirements of this system limit the speed at

which it can operate, thus affecting throughput. All

the above x-ray systems are discussed in appendix B.
Chapter 4--Research and Development ● 47

Explosives Detection by Magnetic Resonance and

Nuclear Quadruple Resonance

Bulk explosives may also be detected by magnetic

resonance methods-both nuclear magnetic resonance (NMR) and electron spin resonance (ESR).

The general technique is to place a sample in a

uniform magnetic field and to expose it to a radiofrequency (RF) electromagnetic field. Then, the

procedure requires varying the frequency (or the

magnetic field strength) and noting the frequencies

(or magnetic field strengths) at which the sample

absorbs or emits RF energy.

The nuclear quadruple resonance (NQR) method

employs a similar procedure but does not require a

uniform magnetic field. It has been used to detect

both non-nitrogenous and nitrogenous explosives in

the laboratory.

The feasibility of detecting bulk explosives by

NMR, ESR, and NQR in operational contexts has

been studied for several years in the United States

and the United Kingdom. For detecting sheet explosives containing nitrogen or chlorine, NQR appears

especially promising. The final report of this assessment will discuss in greater detail the detection of

bulk explosives by these three techniques.

Vapor Detection by Chemical Means

Man-made vapor detectors must perform three

general steps. First, a sufficiently large sample of

molecules must be collected. Second, interfering

materials and impurities must be removed, the

sample must be concentrated, or both. Finally, the

remaining material must be tested in a way that will

respond uniquely to the presence of explosive

compounds.

The extremely low vapor pressure of many of the

materials listed in table 4-1 makes the first step--

collection of an adequately large sample of molecules-a serious challenge (see figure 4-5). EGDN

has the highest vapor pressure among the common

explosives and will be present in a saturated volume

of room temperature air at the relatively high

concentration of 1 part per 10,000. Chemically,

EGDN is similar to the antifreeze commonly used in

automobiles, differing only in that it contains two

nitro (-NO2) groups. Like its antifreeze cousin, bulk

quantities of EGDN exposed to the air are rather

easily detected even by that relatively insensitive

detection device, the human nose.

A saturated vapor of DNT (dinitrotoluene, a

common contaminant in TNT--trinitrotoluene) or

nitroglycerine (NG) will contain about one molecule

of target compound per million molecules of diluent.

Ammonium nitrate (AN) and TNT itself will be

present at a concentration of about 1 part in 100

million (108). The plastic explosives RDX and

PETN are even less volatile, being present in a

saturated volume of air at standard temperature and

pressure at a concentration of one part in one million

million (or trillion—1012). This concentration is

comparable to one shot glass of whiskey in Loch

Ness, about 30 cents out of the national debt or

1 second out of 32,000 years.12 HMX is, by a factor

of about 60, even less volatile. These concentrations

represent saturation, a condition unlikely to be

encountered in the field. Thus, in all likelihood,

substantially less material than suggested here will

be available for capture.

In addition to the vapor pressure of the pure

compound, several factors affect the concentration

of detectable vapor in the vicinity of an explosive. If

an explosive device is contained within a more or

less enclosed small. volume, after an extended time

(on the order of hours or days) the concentration of

explosive molecules within the enclosed space will

build up towards equilibrium conditions. Air from

such a suitcase or drawer or other container would

contain near the maximum possible number of

molecules. If the nearly saturated air could then be

released and sampled, the probability of detection

would be enhanced.

Another factor is the presence or absence of

relatively higher vapor pressure contaminants,

which are often introduced or created during the

manufacturing process. While in many cases these

contaminants have not even been identified, they

nevertheless will cause some of the detectors to

alarm. The concentration of these contamin ants in

the air surrounding a sample of explosive is a

function of their concentration on the surface of the

piece. Thus, they are most easily detected around a

freshly broken piece. As they evaporate from the

surface, their concentration near the explosive’s

surface declines. Molecules of the contaminant will,

over time, diffuse to the surface from within the bulk

l~o~e~ of Frank Conrad, Sandia National Laboratory.
48 ● Technology Against Terrorism: The Federal Effort

Figure 4-5-Relative Volatilities of Some Common Explosives

c.-

1 in 1015

1 in 1014

1 in 1013

1 in 1012

1 in 1011

1 in 1010

1 in 109

1 in 108

1 in 107

1 in 108

1 in 105

1 in 104

1 in 103

1 in 102

1 in 101

o

HMX

●

. ——— — — — —— — — —— — — —— —— — — — ————— —

1 ppt

RDX

●

1 ppb

TNT

.— — ————— —— ——— — — —— — — ● —— —— — ——— - — — — —

N H4N 03

●

1 ppm

I I I

DNT

●

NG

●

EGDN

●

I I I

100 200 300

Molecular weight of explosive

SOURCE: Sandia National Laboratories, 1990.
Chapter 4--Research and Development ● 49

of the explosive but this is a relatively slow process.

Therefore, while such contaminants can be a benefit

to the detection process, their presence cannot be

relied on.

Finally, the presence or absence of physical

carriers will have a profound effect on the motility

of explosives molecules. Many researchers now

suspect that most sniffers are not responding to

molecules of the explosive compound in the pure

vapor state, but rather to molecules attached to small

carriers such as dust specks.

The relatively high electronegativity of these

explosive compounds is a mixed blessing. It causes

the molecules to be “sticky,” rather in the way that

static electricity makes balloons cling to a wall. This

electronegativity is helpful for detection in that it

makes the explosive compounds rather unique

among organic molecules in their ability to attract

and retain electrons, thereby forming negatively

charged species (anions). The formation of anions is

used by several detection schemes in testing for the

presence of explosive in a sample. But this same

property also causes difficulties for detection because the molecules bind to surfaces so strongly that

shaking them loose in order to sweep them into a

detector is not easy. Further, this affinity of the

molecules for surfaces further depletes their concentration in the air sample. These twin effects form

both the basis and the bane of many devices used to

increase the concentration and number of molecules

at the detector part of a sniffer.

The first stage of a sniffer will usually sample the

incoming air by drawing it over a surface onto which

the sticky explosive molecules attach themselves. In

this manner, the molecules contained in a large

volume of air maybe captured. Later, on heating the

surface, the molecules are driven off. By performing

this heating step in a stream of gas of much smaller

volume than the originally sampled air stream, the

concentration of the explosive molecules is enhanced. Unfortunately, not all (or even most) of the

molecules are actually shaken loose from the adsorptive surface by the heating step. Thus, while the

resulting stream contains a greater concentration of

explosive molecules, there is, nevertheless, a decrease in the absolute number of molecules available

for detection.

The thermal instability of these compounds is a

problem because the same aggressive efforts @eating) sometimes needed to separate a sample of the

explosive from a substrate, so that it may be

channeled to a detector, can also cause the compound to degrade into smaller fragments that go

unrecognized by the detection equipment.

On the other hand, some detection techniques

actually depend on a related property, the frangibility (fragmentation) of these compounds. On impact

with the proper targets (70 eV electrons or atoms of

an inert gas, for example), these molecules will

fragment. Under the right conditions, the kind and

number of fragments into which the explosive

molecules break down is predictable. In this manner,

the presence of an explosive compound in the tested

vapor may be confirmed. The two-stage massspectroscopy device described in appendix C takes

advantage of this property.

The capture of a sufficiently large number of

molecules of the explosive compounds probably

constitutes the most difficult step for the sniffers.

The explosive compounds do not shed many molecules into the air on account of their low volatility,

and, consequently, successful vapor detectors must

be sensitive to the presence of pico- or even

femtogram quantities of material (10-12 and 10-15

gram respectively). The performance of vapor detectors can also be degraded by the presence of

interfering materials and impurities, which can both

trigger false alarms and lower the sensitivity of the

equipment to real explosives. Finally, the effectiveness of the system is dependent on matching the

detection strategy to the properties of the specific

explosive compound present.

In the United States, until very recently, tests

conducted on sniffers did not yield very favorable

results. In March 1988, the FBI examined the

performance of four commercially available explosives vapor detectors under realistic conditions.

While most of the instruments could easily and

reliably detect pure samples of the higher vapor

pressure materials (EGDN and NG) under laboratory

conditions, results in real world scenarios, including

searches of suitcases and cars, were disappointing.

The authors concluded:

13’ ‘Explosive Detector Evaluation%’ FBI Laboratory, Forensic Science Research amd Training Center, FBI Academy, Mar. 21-24, 1988, p. 65.

A limited distribution report. Registered copies for ofllcial use are available by writing on letterhead to the FBI Academy, Quant.ice, VA 22135.
50 ● Technology Against Terrorism: The Federal Effort

[T]he challenge still remains to find a small handheld detector able to reliably detect inorganic and

plastic-based explosives in operational scenarios.13

In tests conducted by the FAA in 1989, another kind

of sniffer, a chemiluminescent device (see app. C),

also did not perform well. Results of this test have

not been published. On the other hand, several

foreign countries have found considerable promise

in more advanced chemiluminescent units recently

tested in a number of applications, including some

baggage screening for airline security. In late 1990,

the FAA ran tests on several vapor detection devices.

The results of these tests have not yet been made

public.

Vapor detection schemes do have certain advantages. They seem to be more amenable to automation

because the typical output of the machine is a fairly

simple electronic signal that can be satisfactorily

interpreted by a microprocessor. No complicated

pattern recognition is involved. Further, by generally avoiding the use of large radioactive sources and

their attendant public relations problems, shipping

and exporting these machines is a simpler matter.

For the same reason, unlike detectors using large

amounts of ionizing radiation, they can be used to

screen radiation-sensitive subjects, such as humans.

Also, because they generally do not require any

shielding, they can be smaller and more portable and

thereby more versatile than bulk detectors. For

example, they are available as hand-held units that

can be carried around a test object by a single person.

They are much cheaper, usually by a factor of 10 and

sometimes even by a factor of 50 or more, than

nuclear-based devices. Finally, techniques are being

developed to compensate for the low volatility of the

explosive compounds. For example, some experts

have had success using a swab to wipe down a

suspected person or object, then testing the swab for

residues. These detectors are being used in a variety

of search scenarios.

A discussion of some of the different techniques

and devices under development for explosives vapor

detection may be found in appendix C.

Taggants

Given the difficulties in detecting small but

deadly amounts of explosives, either by vapor

detection or nuclear techniques, alternative possibilities need to be explored. A suggestion to this end,

which has been discussed for years, is to place some

agent in the explosive during manufacture that

would make detection far easier. In the past, the

principal goal of tagging explosives was for forensic

purposes, that is, to try to aid in discovering the

manufacturing origin and procurement path of an

exploded bomb by careful examination of the

residues of the explosive at the scene. Many

possibilities were suggested and analyzed in an OTA

report in 1980.14 Suggestions for incorporating

taggants in explosives were strongly opposed by

manufacturers and by the National Rifle Association

for several cited reasons: unacceptable added cost,

complication to the manufacturing process, reduced

performance (particularly of ammunition), and lack

of effectiveness for detection, since foreign or clandestine manufacturers would not use the taggants.

However, in response to recent terrorist attacks on

civil aviation, there has been a renewal of international interest in adding taggants to explosives. The

International Civil Aviation Organization (ICAO)

has organized a technical group to study this matter,

and research is centering on a small number of

possible chemical additives. Of particular interest is

the fact that former Eastern bloc countries, including

Czechoslovakia, have expressed strong interest in

cooperating in this endeavor, doing so even prior to

the recent accession of President Havel and a

noncommunist government. The cooperation of

Czechoslovakia would be particularly valuable because it is the manufacturer of SEMTEX, a favorite

plastic explosive of Middle Eastern terrorists that

was apparently used in the downing of Pan Am 103.

Further, Czechoslovakia and the United Kingdom

have cooperated in a joint United Nations effort to

develop an international agreement on tagging. The

likelihood of an international convention that mandates the inclusion of a chemical taggant during

manufacture of all plastic and sheet explosives

appears far more promising than it did some years

ago.

13~~Explosive Detector EvdtMtioQ’ FBI Laboratory, Forensic Science Research amd Training Center, FBI Academy, Mar. 21-24, 1988, p. 65.

A limited distribution report. Registered copies for official use are available by writing on letterhead to the FBI Academy, Quantico, VA 22135.

14u.s. Conmss, Ofim of T~~olo~ Assessment T’ggant~ in Explosives, OTA.ISC-116 (Sprin@eld, VA: Natior@ Technieal r.UfOImtitiOn

Service, 1980).
Chapter 4--Research and Development ● 51

The principle of a chemical taggant is to introduce

into all manufactured explosives a particular type of

molecule that is easily detectable by vapor detectors.

There are several requirements for such a taggant. It

must be cheap and usable in small amounts, not

unduly complicate the manufacturing process, and

be easily available, nontoxic, safe, and easily

detectable. A multinational working group is investigating several compounds. All are explosives

themselves with relatively high vapor pressures,

which would aid detection with sniffers. Other

compounds are also being investigated. The feeling

among the participating officials is that the international group may agree on a single compound in the

near future. Efforts would then be made to arrive at

an international manufacturing convention.

The only United States participation in tagging

research is being carried out under a small contract

with the U.S. Army Armament Development Command at Picatinny Arsenal in New Jersey (about

$35,000 in fiscal year 1989 and a like amount in

fiscal year 1990) with funding provided by the

TSWG.

Another approach, pursued only on a theoretical

level thus far, has been suggested. The concept

considers the possibility of doping all explosives

during manufacture with a minute amount of a

radioactive isotope. Taggant concentrations as low

as 10-12 grams per kilogram of explosive should

allow one to detect a signal above ambient, natural

radioactive background. Passengers and baggage

would be screened by detectors that look for the

characteristic radioactive emission at entry-ways in

airports, similarly to current practice with x rays for

carry-on baggage and with metal detectors for

passengers. Unlike the chemical additives case,

detection would not rely on the presence of vapor.

Attempts by a terrorist to shield the gamma rays

would be detected because of the large amount of

heavy metal required.

The radioactive content of a bomb composed of

the doped explosive would be less than that in a

human body. Consequently, health hazards would

be essentially zero. Many more orders of magnitude

of radioactive exposure would be received by an

airline crew and passengers from exposure to the

natural background during a flight than by being

surrounded for hours by explosives doped with this

taggant.

One problem with this latter approach is the

potential public opposition to anything radioactive,

even if the quantities involved were so small that

exposure to a passenger carrying the explosive on

his body would be much lower than he would

receive, for example, from sitting next to another

person (industrial exposures would also be insignificant). Measurements in support of this concept have

yet to be made. If background levels turn out to be

higher than anticipated in an operational airport

situation, more of the taggant might be needed

(although the concentrations would still be far less

than should occasion any health concerns).

However, there are two serious problems with

tagging of any kind. The first is the large amount

of explosives already in the hands of terrorists

and their state sponsors. 15 lt would take years,

perhaps 5 to 10 or more, before this material would

become unreliable. Nevertheless, one can argue that

one should start at some time to tag explosives,

because eventually the material in the current world

inventory will run out.

But there is a more difficult objection, namely

that some terrorist groups now have the ability,

possibly as individual groups or else through

contacts with their state sponsors, to make their

own plastic high explosives. These illegitimate

manufacturers will, of course, not tag their explosives, and no international accord could guarantee

that they would. Therefore, tagging would only

raise serious difficulties for terrorists who have

no access to illegitimate, nontagged sources and,

even for them, probably not until some years in

the future.

DEFENSE AGAINST CHEMICAL

AND BIOLOGICAL WARFARE

(CBW) AGENTS

Although few overt and no major events have yet

taken place, there is a consensus that a chemical or

biological (CB) terrorist threat exists. A brief

discussion of the threat was given in chapter 3. The

level of technological sophistication required to

mount a terrorist attack of this type is not particularly

Issee, for exanlple, The Washington ZJo~t, Mar. 23, 1990 forthereport by President Havel of Czechoslovakia% who announced tit tie previous W@e

had sold 1,000 tonnes of SEMTEX to Libya and further amounts to other terrorist-sponsoring states, such as North Kore~ Syria, IrarL and Iraq.
52 . Technology Against Terrorism: The Federal Effort

high. In fact, for some scenarios, it may be lower

than was the case for some of the sophisticated

bombs that have been used against civilian aircraft.

Further, the ability of Libya, Iraq, and Iran to

produce chemical weapons has been known from

open sources for some time, and all of these

countries have sponsored active terrorist groups that

have attacked civilian populations with the aim of

producing many deaths.

However, in the absence of actual examples of

terrorist attacks employing chemical or biological

agents, it is extremely difficult to substantiate or

even define the threat accurately. In lieu of concrete

evidence, and armed with some intelligence data,

planners have found it necessary to look to U.S.

military programs (which are, however, designed for

battlefield applications) as a guide for devising

responses to such events.

Research and development into the problem of

detecting CB agents, either on the battlefield or in a

terrorist situation, is not very advanced. Detection of

biological agents and subsequent (or, frequently,

concurrent) diagnosis of the agent causing the

symptoms is relatively undeveloped. As a point of

reference (that is, admittedly, 15 years old), in 1976,

it took the full resources of the U.S. Government

7 months to isolate the Legionnaires’ disease Legionella pneumophila bacterium when it was discovered.

l6 17

The U.S. Army has primary responsibility for

detection of chemical and biological agents. It has a

modest research program and a few field detector

systems under current development. The Army also

maintains related intelligence activities that continually assess the chemical and biological threat,

including the likelihood of their use by terrorists.

Biological agents are powerful; very small quantities can produce serious and widespread injury.

They may be divided into three classes: those that

infect those immediately exposed, but do not easily

contaminate others who come into contact with the

victims; those that are highly contagious and may

cause epidemics; and those that are not living

organisms or viruses, but are chemicals produced by

organisms and only affect those exposed to them. An

example of the first type is anthrax; the second type

may be exemplified by Yersinia pestis, the bacteria

that causes plague; the third type is comprised of

toxins, such as botulinum toxin.

Table 4-4 gives some typical detection goals set

by the U.S. Army for several of the most common

chemical and biological agents envisioned as possible threats. The quantities cited give an idea of their

effectiveness. United Nations experts have estimated that a person drinkin g 100 milliliters (less

than a half cup) of untreated water from a 5 million

liter reservoir would become severely sick and

perhaps die if the reservoir had been contaminated

by l/z kg of Salmonella typhi (the causative Organism of typhoid fever), 5 kg of botulinum toxin (a

plausible toxin warfare agent), or 7 kg of staphylococcal toxin (another plausible warfare toxin). By

contrast, it would require 10 tons of potassium

cyanide (a chemical warfare agent) to contaminate

the reservoir to the same toxicity.

Chemical and Biological Agents—Point and

Remote Detection

Preparation for such an ill-defined, amorphous

threat is obviously a problem. Very little work

directly aimed at the terrorist threat has been done;

more research has been aimed at the battlefield

threat. However, some of the detection research

being conducted by the Army for its chemical and

biological warfare defense program has direct applications to counterterrorism. There is also some

research specifically directed at CBW counterterrorism that is being conducted at the Army Chemical

Research, Development and Engineering Center.

The battlefield situation differs from the terrorist

situation in some aspects. In the battlefield, airborne

agents would be the main, although not the only

concern. The role of technology is aimed at first,

early detection to permit doming of protective gear;

second, assessment of potentially contaminated

areas to determine if, indeed, there is contamination,

and, if so, what kind there is; and third, decontamination of contaminated areas.

In the terrorist case, large concentrations of

people or high-profile fixed facilities (e.g., embassies) could be targeted. Also, agents might be placed

in water supplies as well as transmitted through the

16Re@o~wtive@, res~hers have establish~ that this microorganism did cause recorded disease as MIY as 1943.

IT~ere is r=ent evidence tit ~pabflities w significantly improved: the Army recently rapidly identifkd a 5* of Ebola vfis in a colonY of

monkeys to be used for medical research in Reston, VA.
Chapter 4--Research and Development ● 53

Table 4-4-Chemical and Biological Agent

Detection Goals

Chemical agents Detection goals in air

GB (Sarin) . . . . . . . . . . . . . . . 0.05 mg/m3

GD (Soman). . . . . . . . . . . . . 0.05 mg/m3

VX . . . . . . . . . . . . . . . . . . . . . 0.002 mg/m3

HD (a Mustard Gas) . . . . . . . 5.0 mg/m3

L (Lewisite) . . . . . . . . . . . . . . 5.0 mg/m3

SOURCE: U.S. Army, 1990.

air in aerosol form. Early detection is of importance,

but to allow timely evacuation to safe locations, not

(unless the targeted population has been prepared

and is in a high state of alert) for donning protective

clothing or masks. Further, large areas may have to

be monitored for long periods of time. For monitoring airborne agents, this would demand long-range,

automated detectors with low maintenance problems for adequate early warning protection. The

requirements for assessment and decontamination

after an attack would demand similar technologies to

the battlefield case. However, in the terrorist case,

time scales for action would be longer than in the

battlefield. Moreover, the areas to be covered might

be much larger.

There are three generic types of systems under

investigation for detecting CB agents: point detectors for early but relatively unspecific warning in the

field, assay systems for specific identification of the

agents involved but not necessarily intended for

field use, and stand-off detectors that can monitor

clouds-of chemicals or, perhaps, biological agents,

from some distance. In contrast to explosives

detection for airline security, there is no welldefined requirement that mandates exactly how

detection systems might be used. Much of the

current research is aimed primarily at producing

detection or assay capability that could be available

in Army field situations and in selected special

locations, such as U.S. Army chemical and biological warfare laboratories or Public Health Service

laboratories. Beyond detection systems, there is

some portable protection equipment being developed for emergency use in special highly critical

situations.

A major difficulty in the detection of a chemical

or biological attack is the variety of possible agents

and the need to search for (often specific) known

agent signatures. This immediately limits the detection process to those substances known to the

defender. A new, previously unknown substance

might well go undetected, at least for a while.

Unfortunately, there are no general characteristics of

agents that one can look for. Point detection systems

are generally based on introduction of antibodies for

the specific agents, and the subsequent detection of

the antibody/antigen reaction or resulting compound. The detection goals vary with the agent, as

seen in table 4-4, depending on human sensitivity

levels. Generally, these goals are set at less than a

milligram per cubic meter, with chemical agents

requiring fractional milligram sensitivity and biological agents usually requiring higher levels, but

with great variety. The declared battlefield requirement for detection of botulinum toxin, for instance,

demands the ability to find quantities as low as

0.0007 mg/m3

. Instruments usually consist of a

sample acquisition system (e.g., a vacuum cleaner),

a sample preparation step where the antigen is

introduced, and a sensor system, which is supported

by computing equipment that displays the result or

provides an alarm.

For stand-off (remote) detection, most concepts

employ passive optical and laser technologies. This

field has benefited from research performed in the

related field of environmental and atmospheric

monitoring. Optical and laser radar technologies are

also under development for a wide variety of other

applications, including various Department of Defense missions. The search for counterterrorist

technology in this domain often involves applications or adaptation of technological developments

from other fields.

Stand-off detection equipment should be small

enough to be mounted on a mobile platform, such as

a van or helicopter (although there are also some

freed site applications for guarding a point site or

perimeter). The goal is to observe an area with a

radius (stand-off distance) usually on the order of

1 to 10 km. Presumably, this range would give the

intended victims enough warning time to react and

try to protect themselves. The instrument should be

able to scan the critical area, detect the presence of

a cloud of dangerous vapor, determine its location,

and discern its critical agents. Some of the optical

and laser systems are also called onto detect ground
54 ● Technology Against Terrorism: The Federal Effort

contamination. Both stand-off detectors and point

detectors need to know just what agents to look for.

For remote optical detection, the emission or absorption spectrum of the agent must be known in advance.

Appendix D provides a discussion of research

projects aimed at developing detection of or protection against terrorist attacks using chemical and

biological agents.

PHYSICAL PROTECTION

In this section, and for the rest of the chapter, the

bulk of the discussion will be generic rather than

specific. However, a few illustrative projects will be

discussed in order to give a flavor of interesting

avenues of research that may be appropriate and

promising.

Rather than provide a compendium of detailed

barrier information, this section describes briefly a

number of well-known, available technologies, and

refers to some documentation for further information. Development efforts in this area are usually

engineering refinements rather than efforts to develop radically new technologies or techniques.

Physical protection encompasses a wide variety

of technologies that have been aggressively developed for several decades. First, the military has long

had an interest in providing physical protection for

its bases and facilities, at home and abroad, during

war and peace. Further, since the advent of nuclear

weapons, the Atomic Energy Commission and its

successor agencies, most recently the Department of

Energy, have devoted considerable effort to the vital

task of protecting and maintaining control of nuclear

weapons and the special nuclear material (enriched

uranium and plutonium) that fuels them. Both the

Department of Energy and the Department of

Defense have active research programs to improve

levels of physical protection around both freed and

mobile sites. The Nuclear Regulatory Commission

oversees an active program of protection of civilian

nuclear facilities, including specific regulatory

standards for such equipment. Finally, private corporations, often being the targets of terrorist attacks,

have pursued physical security for many years,

resulting in a thriving industry that furnishes protective devices for their needs.

Much of the purely military effort takes place at

Fort Belvoir, at its Research, Engineering, and

Development Center; most of the physical protection research for the nation’s nuclear weapons

complex is directed by Sandia National Laboratory.

Also, considerable efforts are funded by the Defense

Nuclear Agency. Many of the technologies (e.g.,

advanced barriers, perimeter detection systems,

alarms) that have been developed by these agencies

are applicable in a number of counterterrorist contexts.

In the counterterrorist context, physical protection

is a function of likely target type. There are domestic

freed sites, such as government buildings, military

bases, and airports; there are overseas sites, such as

embassies and, again, military bases. Buildings

belonging to private U.S. corporations, both in the

United States and abroad, may also be targets, as

might gathering places for U.S. citizens, such as

particular bars or theaters. Plants associated with the

nuclear weapons complex are an obvious target for

nuclear terrorism. Mobile targets may be military,

but they may also be civilian aircraft. It is of interest

to investigate whether one might harden aircraft

against internal explosions, or protect them

against missiles while in flight.

Concerning airline security, there currently are

programs to design security systems for airports that

would make both hijacking and sabotage more

difficult. In this field, lessons learned in designing

security systems for other facilities, such as plants in

the U.S. nuclear weapons complex, may prove

useful in assembling integrated systems for airports.

Of course, changes must be made in system details,

but design methods and many individual technologies (e.g., weapons and explosives detectors) employed in the nuclear security effort maybe of use.

A key question, however, is the eventual cost of such

systems.

Sandia National Laboratory has been given the

role of lead laboratory for research and development

in physical security for the Department of Energy.

For several decades, it has performed work in

developing, testing, and evaluating barriers, sensors,

alarm systems, and delaying techniques.18 Many

component technologies are already commercially

available. Originally aimed at developing the best

possible protection for nuclear weapons, whether

lsFor~er~dde~~ discussion of many sensor and barrier technologies, see Sandia National Laboratory, SAND87-1924 to sm87-1929, JulY

1989.
Chapter 4--Research and Development ● 55

under transport or at fixed sites, whether in the

United States or abroad, Sandia’s mandate has more

recently extended to assisting other agencies, such as

the Department of State, the Secret Service, and the

Bureau of Engraving and Printing. Safeguards

engineering research at Sandia, under which aegis

most nuclear weapons protection work is done, is

funded at about $60 million for fiscal year 1990.

Most of this work is not oriented towards counterterrorism, but the results may often be useful for this

purpose.

The principle invoked in designing security systems for many physical protection problems is to

divide the defense’s task into three parts: detection,

delay, and response. The first part deals with

detecting an intrusion or an attack by a malefactor,

and, impossible, identifying and assessing the nature

of the intrusion. The second part covers barriers of

diverse sorts that are either in place or can be

deployed rapidly (within seconds) to respond to the

intrusion. The last of these three parts refers to the

arrival of a military or police force to respond

effectively to an attack. Detailed discussion of this

topic is beyond the scope of the present study,

although mention of technologies for assisting

specific response scenarios is made in the following

sections. Technologies for carrying out the first two

tasks are of interest here. Most of these technologies

are well developed. The task of systems designers is

to integrate the parts into an operationally useful and

economically affordable system. In the area of

nuclear terrorism, this has been done, although

upgrades are continuing.

Detectors and Alarms

Detection may be accomplished by many methods, most of which are commercially available for

domestic or commercial security systems. Alarms

and detectors may be deployed along a perimeter

around a site or in isolated rooms that are normally

unoccupied. Microwave sensors emit microwave

radiation and operate either by observing the blocking of a beam by an intruder (bistatic mode, with a

separate transmitter and receiver) or by receiving the

reflected radiation of a transmitted beam from an

intruder by means of a receiver that is collocated

with the transmitter. Similar techniques can be used

at wavelengths shorter than radar, namely in the

infrared regime. Also, since most living objects of

interest are warm (about 310 K), they emit infrared

radiation at wavelengths between about 10 and 30

micrometers. Passive infrared detectors use this fact

to detect living objects in a protected zone. Passive

infrared detectors are being developed by the

Defense Nuclear Agency and the U.S. Army as well

as by Sandia for specific military needs. Other types

of detectors, seismic sensors, pick up the small

vibrations generated when a human or animal is

simply walking nearby. Still others detect variations

in electrical fields when a passing intruder’s body

changes the average dielectric constant in his

vicinity. One potential application of alarm technology would be to place sensors around unattended

commercial aircraft so that persons attempting

unauthorized access would be detected and, if

possible, identified.

Each of these techniques can, in principle, be

defeated by a variety of countermeasures. A cleverly

designed security system makes use of several

techniques together so that countering all of them

becomes an extremely cumbersome and complicated

task for a would-be terrorist. Another consideration

in designing a system, particularly one for outdoor

use, is to employ methods and combinations of

technologies to prevent stray animals, wind, or

naturally occurring events from triggering alarms.

No system is useful when the false-alarm rate is

high.

Another useful detector is the closed-circuit TV

camera. Sophisticated electronic and software additions have been developed that can make a mundane

security system far more effective. By comparing,

for example, a current image with an earlier one,

scene changes may be highlighted or, by using

clever algorithms, the system may trigger an alarm

when scene changes corresponding to a serious

threat occur. The software may detect changes from

scene to scene (perhaps only seconds apart in time)

that indicate a human- or vehicle-sized object moving

toward a protected zone at a rate consistent with the

expected speed of an intruder.

Barriers

Barriers may range from simple high fences (not

a very good delaying technique for a determined

adversary) to very thick reinforced concrete walls.

Barriers may be alarmed as well. Barrier design is

chosen to be applicable to the specific site. A mobile

military site may have a simple fence and rely on

distant perimeter alarms to protect a central zone. An

embassy may have stand-off barriers, such as high
56 ● Technology Against Terrorism: The Federal Effort

fences or walls that are difficult to scale. One may

emplace high berms (to deflect pressure waves from

a blast and to block shrapnel) and vehicle barriers

scores of meters from the defended site to help

protect against car bombs. Very sensitive items,

such as nuclear weapons, maybe protected in a vault

shielded by reinforced concrete.

Delaying techniques have been developed by

Sandia for use inside buildings. The range of

technologies is diverse and impressive, not always

relying on radically new, high technology engineering. These may run from smoke- and liquid-foam

generating devices that can effectively impede and

slow down intruders to coils of razor wire that may

be dropped from a ceiling to fill a room.

Building Hardening

Architectural design and mechanical engineering

are two disciplines of particular use to the State

Department and would be of use to any entity

wishing to protect its buildings against catastrophic

collapse induced by explosions. One may design or

(less desirably) retrofit buildings to make them more

resistant to explosions, either nearby or within.

Following the attacks on U.S. Embassies in Beirut

and Kuwait in the early 1980s, the State Department

instituted a program to spend several billion dollars

on improving security and blast resistance at its

overseas sites. Features that should be avoided

include unreinforced masonry, wood frames, cantilevered elements, and heavy concrete buildings

supported by thin columns. In general, low buildings

with closely spaced ties above and below floor slabs

and with relatively short unsupported spans are more

resistant. Many engineering practices useful in

earthquake-resistant design are also applicable in

defending against explosions. There is little that is

new here, but there is a challenge in designing

buildings that are esthetically pleasing, that retain an

openness that the United States wishes to maintain

in its public buildings, and that still provide some

protection against serious sabotage. Modifying existing structures to have such features is more

difficult and expensive than incorporating them

from the beginning.

Aircraft Hardening

An area receiving new interest is the possibility of

hardening parts of aircraft to prevent, impede, or

mitigate terrorist acts. If appropriate lightweight

armor could be found that would, for example,

protect the flight deck from gunfire, this would be

helpful in controlling attacks on the crew. Such

attacks are infrequent, but do occur, as in the case of

a PSA flight in 1987, when a disgruntled exemployee shot the crew and caused the aircraft to

crash, killing all aboard. Areas that might be

protected could include crew seats, the bulkhead

separating cabin from flight deck, and the cabin

door.

Another promising topic being investigated is

whether baggage containers could be constructed of

lightweight, protective material that could partially

contain an explosion, venting it in a semi-controlled

manner. Possibly, blow-out panels could be built

into aircraft fuselages at positions corresponding to

venting points of the containers. These might

prevent propagation of holes or tears in the aircraft

skin that could lead to catastrophic failure. Thus, the

integrity of an aircraft might be protected during

flight. Of course, a large enough explosive would be

able to breach any containment one might design,

since the containment mass would have to be limited

in an aircraft. However, if the required size of an

explosive were driven up significantly, this would

greatly facilitate the task of explosives detectors of

all types in preventing such items from being

brought on board.

As an example, one corporation, QSI, Inc., has

developed a lightweight armor, designated QX-90,

which is composed of laminates of various composites. Originally designed for body armor, and

successful at stopping 7.62 mm armor-piercing

ammunition in a 7

/32 inch layer, this product is being

examined for such an application.

Further, the FAA Technical Center has a program

to examine means of reducing and mitigating the

vulnerability of aircraft to explosions in flight. These

would appear to be useful lines of research to pursue,

since payoff could be very high, and (at least initial)

research costs in materials research would be

relatively low. Our subsequent report will examine

this topic further.

Access Control

Control of ingress to and egress from protected

areas is a necessary part of physical security for

many applications. In general, the facility’s security

plan requires individuals who wish to pass a secure

portal to be screened for access. Usually, the

individual will be an employee who requires access
Chapter 4--Research and Development ● 57

to the area in order to perform his or her job. Also,

this process permits a control center to keep track of

who is where in the facility by means of a

continually updated database.

A potential area of utilization is airport protection.

It is necessary to prevent unauthorized persons from

gaining access to critical zones, for example, those

in which aircraft are located. In busy airports, there

are thousands of employees and hundreds or even

thousands of portals. Airports are now required by

the FAA to control access to air operation areas in

order to prevent the entry of unauthorized persons

and ground vehicles.19 Practical implementation of

this rule is currently underway. About half the

Nation’s major airports have submitted access

control and airport security plans. Some difficulties

have arisen: now that specific standards are being

addressed and described, objections from airport

operations authorities have developed, particularly

regarding cost and operational questions.

The problem of maintaining adequate entry control is complex. A successful system requires

sophisticated computer control and system design as

well as devices that can automatically grant access

to legitimate requesters. More sophisticated versions

will add the ability to grant different levels of access

to persons with different levels of authorization.

Some areas might be accessible to all employees and

other more protected areas to only a few.

The technology to support access control is

well-developed and commercially available. The

most common and simplest technique uses an

identity card combined with a Personal Identification Number (PIN) for each authorized individual.

However, direct measurements of unalterable characteristics of the individual provide surer identification. Among more advanced technologies are four of

interest: voice pattern recognition, fingerprint examination, hand profile measurements (in which several dimensions of an individual’s hand are automatically measured), and retinal pattern identification.

One could also simply use a TV camera-a remotely

located security officer could compare the image

with a photograph. Automating this process is a

technology that requires further work to achieve cost

reductions.

The four more advanced identification technologies noted above have been evaluated by Sandia

Laboratory and all were found practical. The quickest among the evaluated models was the hand profile

monitor, which required less than 5 seconds for

examination and had very low rates of false positives

and false negatives (less than 1 percent).

An identification technique now in the early

research stage examines the pattern of an individual’s iris. This is done with a TV camera that is

linked to a computer employing appropriate software algorithms. The iris pattern of an individual

appears to be a highly specific identifier. A computer

can be taught to recognize distinctive features of the

iris in a TV image and then express them in a digital

code, which is then stored in a computer or on an

identification card. In possible border-control applications, irises of those seeking entry would be

imaged by a TV camera, computer-coded, and

matched by computer against the iris patterns of

those (e.g., criminals or terrorists) on watch lists. A

central problem in this application is obtaining

detailed images of the irises of undesirables. In any

case, many matches may have to be attempted before

one is found, so the matching algorithms and the

computer need to be fast.

In a more typical access-control application, irises

of those seeking entry may be matched against the

irises of those authorized access.

Baltimore-Washington International (BWI)

Airport Project

Sandia National Laboratory is conducting a study,

funded by the FAA Technical Center, to investigate

how security might be upgraded at typical airports.

This multiyear project, called the Enhanced Security

Demonstration Project, is underway, using Piers A

and B at Baltimore-Washington International Airport as a test-bed. Sandia is applying to airport

security those design techniques developed over

decades for protecting nuclear installations. Much of

the planning is done by experts who have been

working on physical security for years. But the effort

also uses computer programs to model the physical

security system of the airport in an effort to find and

close paths that malefactor might use for hijacking

or sabotage.

Currently, airports can defend themselves well

against one or a few disorganized hijackers. The goal

of the project is to design an airport security system

1914 CFR 107.13, F* Regulations.

292-884 0 - 91 -- 3 : QL 3
58 ● Technology Against Terrorism: The Federal Effort

that would protect the airport and aircraft against an

organized group attempting to hijack or sabotage

aircraft, including the case in which there is an

‘‘insider’ with access to restricted areas of the

airport who colludes with the terrorists.

One technique is the use of a computer model

developed by Sandia National Laboratories, called

ASSESS, that tries to discern all paths by which

terrorists might introduce weapons or bombs aboard

aircraft. The number of paths increases geometrically with the number of portals or potential points

of access that one must defend. If one includes the

case of colluding insiders, the situation becomes that

much more complex. A computer can use its

enormous calculating power to find subtle vulnerabilities not always apparent to human security

experts.

The Sandia project is studying all aspects of

security upgrading, from selection of optimal explosives and metal detectors to means such as installation of one-way revolving doors at passenger concourses to ensure that all individuals pass portals

only in the authorized direction. Other concerns are

the installation of optimally placed closed-circuit

TV cameras at portals, employee screening at

employee access portals, and duress alarms at

portals, so that security personnel may surreptitiously indicate to a command post that a serious

problem has arisen. Close attention is being paid to

the layout of the facility. If, for example, public

parking lots are close to areas where aircraft are

found, detectors and barriers should be installed to

prevent someone from throwing a weapon or bomb

over a fence to a waiting conspirator with immediate

access to aircraft. In addition, human factors are

being investigated. These include motivating security personnel, making their tasks easier, and monitoring their activities.20

Sandia intends to implement upgrades at Baltimore in the 1991 to 1992 timeframe that would

protect against a sophisticated hijacker threat.21

Following this, further upgrades will be aimed at

preventing well-organized terrorists from introducing bombs aboard aircraft. It remains to be seen

when this latter aspect of the project will be finished,

and what capital costs would be required to upgrade

the security system accordingly at a typical airport.

Efforts to develop similar systems to design

security upgrades for airports are also being considered by private firms. For example, Ameritec of

Alexandria, VA is trying to adapt techniques they

have developed for designing protective systems for

embassies and other fixed sites. Another firm,

Aerospace Services International, of Herndon, VA,

is actively engaged in the design of security upgrades at Dunes International Airport and in the

design of security systems at the new Denver airport.

INCIDENT RESPONSE

This section deals with technologies that could be

used to deal with terrorist actions that last for a

significant length of time rather than occurring

essentially instantaneously (e.g., an explosion

aboard an aircraft or a car bombing). The type of

incident that is of interest is a hostage holding

situation on an aircraft, in another vehicle, or at a

freed site. There are at least two types of tools that

would be of great potential use. One would be a

detector that would allow authorities to monitor

what was going on inside an enclosed area in which

hostages were held, so that an assault might be

planned most effectively. In the aircraft case, it

would be useful to know, for example, where the

terrorists were located, especially at the moment of

assault, how they were armed, or whether any

hostages were injured.

Another useful device would be a less-than-lethal

weapon that would allow authorities to disable

terrorists during an assault while not permanently or

seriously harming them or the hostages. A dose of an

agent could be administered either through inhalation or through percutaneous (through the skin)

penetration. Such a hypothetical agent could be

introduced into a confined area where hostages are

held to disable the terrorists but not harm the

%ecently, United Airlines installed “high-tech’ security systems at O’Hare International Airport in Chicago and Denver’s Stapleton International

Airport. As well as employing the latest inx-rayluggage scanners, United has looked closely at improving personnel performance throughmanagement

techniques. One example is the practice of rewarding positive performance by both monetary and professional means. Good performers are offered the

possibility of employment directly with the airline instead of remainingas “rent-a-cops” with a contracting security agency. Another example is the

open microphone at passenger entry points that permit supervisors to monitor conversations among the security persomel. Reportedly, since installation

of the new system, the number of detected contraband items has signiilcantly increased. A similar system has also recently been installed at Dunes Akport

in Washington.

Zlmt is, awell-org~~d gTOUp of hijack~s with advanced technical knowledge, unlike the primitive threats faced in the United S@teS tithe 1970S.
Chapter 4--Research and Development ● 59

hostages. The rescue team could then free the

hostages without risking lives.

There are some difficulties with this scenario. For

example, a terrorist might wire explosives to a

“dead man’s switch,” which he or she would then

hold. After being disabled, the terrorist would then

let go and set off an explosion. This tactic has been

used, but very infrequently. Another difficulty, more

general and more serious in developing such agents,

is that the average dose required to incapacitate

might not be sufficiently less than the average fatal

dose. The very young and very old, and those with

serious cardiovascular or cardiopulmonary problems would then be particularly at risk. Nevertheless, one can imagine many scenarios in which it

would be very useful to have the option of using such

agents (e.g., after the elderly and infirm have been

released), provided the ratio of incapacitating dose

to lethal dose were high enough.

Many classes of incapacitating agents have been

investigated in the past, from LSD and THC (the

active ingredient in marijuana) to glycolates and

tranquilizers, such as chlorpromazine. Some have

been dropped because of safety questions (e.g., rapid

depression of blood pressure or respiration rate) and

others because of lack of predictability in effect (e.g.,

LSD). Ideally, one would wish an onset within a few

seconds or, at most, a minute, with effects that last

for many minutes or a few hours.

Tests on some candidate compositions have been

carried out on animals, but not on humans. One

problem is extrapolating effects from animals to

man. Unfortunately, it appears that as one proceeds

to examine effects on higher species, the ratio of

fatal to incapacitating dose appears to drop. Ratios

of hundreds or thousands (which one would like) in

mice and rats drop to 10s in primates, and are

estimated to be on the order of 10 or less in man.

Work is continuing in this area, not directly under

counterterrorist research, but having clear application thereto. Interest also comes from the National

Institute of Justice, which is looking for incapacitating agents for law enforcement use in lieu of firearms.

DATA DISSEMINATION

Communication among law enforcement, intelligence, and military authorities, both domestically

and internationally, is a vital part of counterterrorist

actions. There are two broad kinds of communicaions that are of interest. One deals with information

and databases on terrorists and terrorism, and the

other concerns information on progress in research

and development of new counterterrorist tools. The

latter sort of communication has been greatly aided

by the existence of the TSWG, although much

information is still not rapidly transferred. For

example, attempts to compose a database on R&D

progress have not yet succeeded, in part due to lack

of funding.

Improvements in some facets of counterterrorist

communications can be achieved through technologies. For instance, data exchange may be improved

through technical means, such as encrypted communications and satellite links. In general, these goals

may be accomplished without developing radically

new technologies; it is usually a matter of designing

and engineering the solution to a well-defined communications problem.

However, since some impediments to information

transfer are a result of classification of information,

turf battles, and legal constraints (e.g., on intelligence information that might be shared among

agencies with external jurisdiction and those with

internal law enforcement responsibilities), improvements in these areas will usually require addressing

policy issues.

There have been some efforts to improve communications among the agencies that have overlapping

authority in the counterterrorist field. Members of

cognizant interagency committees are supposed to

keep each other abreast of their own agencies’

information in the field. Among other things, the

exchange of R&D information is meant to avoid

unnecessary duplication of research efforts by the

interagency group. OTA has not yet assessed the

degree of coordination that this process achieves,

and will report on this in the future.

Another example of interagency data exchange is

the use of a “flash board” system, essentially an

electronic bulletin board among Federal intelligence, military, and law enforcement agencies that

allows time-urgent information to be exchanged on

secure lines in near-real time.

One major technical effort in the data dissemination area about which OTA has so far received

detailed information is a large computer software

and networking effort intended to assemble, update,

and correlate all known information on terrorist
60 ● Technology Against Terrorism: The Federal Effort

groups. One eventual goal is to achieve a rough

predictive capability of terrorist attacks--obviously

not a precise prediction of target, date, and time, but

rather an ability to issue plausible alerts over periods

when attacks might be expected. Another aim would

be to attempt to assess the nature of a specific threat.

The fundamental concept is to arrange information by terrorist group. Information may come from

intelligence sources or simply from an open source

such as press reports. It may include items such as

movements of group members, money transfers,

movement of equipment, or group dynamics and

politics. One important systems aspect is developing

appropriate protocols and formatting to input the

information in an efficient way.

The eventual goal would be to provide general

warnings such as that a given group appears to be

planning an action, with general ideas of the type of

target one might anticipate as the object of attack,

and a timeframe for maintaining an alert.
Chapter 5

Conclusions Regarding Current Research and

Development Into Detection of Explosives

A large number of detection systems are currently

being developed. In addition to SAIC (developers of

the thermal neutron analysis [TNA] method), several vendors have produced prototypes that, they

claim, can usefully detect small quantities of plastic

explosives. Some of these use vapor detection and

some use x-ray imaging techniques. Among the

vendors making such claims are Barringer, Inc.

(vapor), Ion Track Instruments (vapor), Thermedics,

Inc. (vapor), AS&E (backscatter x-ray), and Imatron

(x-ray, using computerized tomography). The x-ray

and vapor systems are significantly smaller and

cheaper than the current TNA device. Further, other

companies, such as EG&G Astrophysics and

Siemann-Heimann, have commercial x-ray systems

available that they claim are useful for explosives

detection at airports.

After reviewing the current state-of-the-art, OTA

sees no evidence that any device, currently at the

prototype stage, is capable by itself of reliablyl

detecting small quantities of plastic explosives in

checked baggage. There are many technologies,

including TNA, that have limited capabilities; however, all have serious flaws. Table 5-1 provides a

summary of the qualities of the principal types of

detectors.

Since each device has serious weaknesses, the

best solution for a security system would be a

combination of different technologies, if this could

be made economically and operationally feasible.

This would exploit the advantages of each technique

while compensating for its weaknesses. As a hypothetical example (not a definitive prescription), a

first step in screening might sequentially employ

vapor detection and x-ray imaging devices, which

are smaller and less expensive than TNA. Those

bags that produced alarms in both systems would go

to TNA and computerized tomography for a further

look. This would reduce the number of heavy,

expensive detectors at each airport, and, if falsealarm rates in the frost step were low enough, the cost

and operational feasibility could be practical.2

Greater attention should be paid to passenger

screening, which could provide a filter that would

greatly reduce the number of bags that the

technical tools would have to examine. If, say, 90

percent of passengers could be eliminated as likely

carriers of explosives through a combination of

profiles, interviews, and matching of passengers

with baggage, the number of bags that required

inspection would be reduced by a factor of 10. This

would reduce the requirements for the explosives

detection equipment with regard to number, size,

and speed of throughput. This “human factors”-

oriented security approach is highly labor-intensive,

but has been used in Israel and by El Al Airlines

worldwide to provide security with a good measure

of success.

Many have criticized the suggestion that this

approach be applied to the United States, on the

grounds that the size of El Al’s operation is minute

compared to U.S. traffic. However, it would be a

mistake to conclude that none of these techniques

and procedures can be adapted from the Israeli

experience for application on U.S. carriers. Further,

where machines are used to aid human decisionmaking, there may be economies of scale in the

United States.3

l~tis, With ah.igh (at least 90 percent) detection probability and a low (at most 5 percent and preferably much less) false-alarrnrate. A Siplcantly

lower detection probability may not be sufllcient to deter attacks by terrorists who are willing to risk the arrest of several operatives in order to achieve

one spectacular success. Regarding false-alarrnrates, at least one foreign country has found that intensive scrutiny of about 3 percent of checked baggage

is feasible without introducing more than a 2-hour delay between check-in and departure. This implies that a false-alarm rate of this order may be

acceptable, at least in some settings.

%thefmt step had a false-alarm rate of, say, 2 percent only 1 bag in 50 would have to be examined by the following step. Then, instead of mquirhg

that eachTNA machine handle a flow of 600 bags per hour, as is currently specified in the FAA rule, published in September 1989 (see below), it would

only be necessary for it to handle 12 bags per hour. This would mean that the number of TNA devices needed at a large airport would be 1 or 2, rather

than 10 to 20.

30ur *repofi will examine this issue further.

-61 –
62 ● Technology Against Terrorism: The Federal Effort

Table 5-l-Advantages and Disadvantages of Available (or nearly available) Explosives Detection Techniques

Type Advantages Disadvantages

Chemiluminescence Cost; size; sees plastics; specificity (determines molecular Slow; needs vapor or residues.

compounds with low rate of misidentification).

Electron capture Cost very low; size;, may see plastics. Slow; no specificity; needs vapor or

residues

Ion mobility Cost; size; may see plastics. Needs substantial development;

needs vapor or residues.

TNA Sees plastics; prototype exists and being tested in airports; Large; expensive; sensitivity currently

automated. No vapor needed. inadequate; false-alarm rates high.

X-ray, dual energy, or In commercial production; high spatial resolution; may see sheets or Not specific to explosives; sensitivity

backscatter. small quantities of explosives; does some discrimination on atomic to small or thin quantities uncertain;

number, but only roughly; cost and size relatively small; can see not yet automated.

other weapons; vapor not an issue.

Computerized Very high 3-D spatial resolution, good for small quantities of Only looks at density; not specific to

tomography explosives or other contraband; prototype exists. Vapor not an explosives; slow; large; expensive.

issue.

SOURCE: Office of Technology Assessment, 1991.

TESTING AND EVALUATION

With a potential market that could reach hundreds

of millions of dollars within the next few years, it is

to be expected that there will be a multitude of

conflicting and highly optimistic claims made on

behalf of many different products. Consequently, a

credible, objective, official evaluation and certification procedure is badly needed. For this function, the

government may wish to turn to an independent

agency or body that is widely respected for integrity,

scientific and technical expertise, and neutrality.

An independent testing authority, outside the

Federal Aviation Administration (FAA), is urgently needed to provide a neutral testing protocol and to carry out such evaluations. It would be

useful, if not essential, if this were to be accomplished and potential devices certified before

rules requiring massive and expensive purchases

of equipment are established. The FAA is on

record as welcoming the establishment of such a

body.4 Following criticism from public officials and

the Victims of Pan Am 103 organization, the FAA

has also recently constituted an independent advisory panel that is to provide outside recommendations on testing protocols. The TNA equipment

should be retested using new protocols.

Establishment of an independent testing panel

would help the FAA avoid future allegations of

conflict of interest. Some observers have criticized

the agency for a perceived lack of objectivity in the

past. These accusations were based primarily on two

facts. First, specific technologies have been funded

by the FAA for several years, creating the possibility

of institutional bias in favor of those approaches.

Second, serious questions were raised about the

procedures used in the San Francisco Airport and

Los Angeles Airport testing of the TNA device.

One possible agency for testing is the National

Institute of Science and Technology (NIST), formerly the National Bureau of Standards. Not having

participated to any important degree in the development of explosives detectors (although it recently

tested a number of vapor detectors for the National

Institute of Justice), it has no perceived “axe to

grind”; it has a well-deserved reputation for scientific and engineering competence, and has performed, as part of its mission, evaluations of a

multitude of engineering and measuring devices.

Another institution with much experience is Sandia

National Laboratory, which has worked in this area

for over a decade. However, Sandia might be

handicapped by the fact that it has worked assiduously on a few technical approaches for a number of

years, and thus may be perceived as having a stake

in developing them at the expense of others. Another

possibility, the National Research Council of the

National Academy of Sciences (NAS), which has

concluded a study of the problem of explosives

detectors for the FAA, is a respected body with the

required technical capability. However, the NAS is

not interested in being a testing laboratory, and,

indeed, is not setup to perform this sort of task.

dTestirnony of Monte Belger before the President’s Commission on Airline Security and Terrorim, Feb. 2, W90.
Chapter Conclusions Regarding Current Research and Development Into Detection of Explosives ● 63

Any of the above institutions, however, would be

excellent choices to develop appropriate protocols

for the testing and evaluation of explosives detection

equipment. In fact, the FAA has contracted with the

National Research Council to develop some testing

protocols for nuclear-based explosives detection

methods.

A further alternative would be to contract with

other outside sources, such as academic institutions,

military laboratories, or private laboratories, to write

protocols and perform the testing. In all cases, it

would be useful to establish an advisory board,

consisting of technical experts from several government agencies (e.g., the FAA, the Departments of

Defense, State, and Energy), academia, and, possibly, the private sector, to oversee the testing and

evaluation process.

MANAGING RESEARCH

Cooperation

A few Federal agencies are funding the major

share of research into detectors for explosives. These

include, of course, the FAA, which, in addition to

working on vapor detectors and TNA, is pursuing a

number of advanced technologies, described elsewhere in this chapter and in appendixes A through C.

As another example, the State Department is funding

Thermedics’ chemiluminescent technology for detection of explosives in packages. A small amount of

other work is scattered among other agencies.

Several specific examples have persuaded

OTA staff that coordination among the agencies,

both regarding cooperation and exchange of

information, is in need of improvement. In recent

months there have been signs of better interagency

communication, but more needs to be done.5

Time From Laboratory To Deployment

A major problem is the length of time needed to

go from laboratory work to deployment in the field.

Although many Americans would like to have

immediately a set of new, devastatingly effective

tools to fight terrorism, the reality is that the time

required to research, develop, prototype, and, finally, to field a particular device is often considerable. It can frequently take as long as 10 years to

bring a new, complex technology to the commercial

market. The first 2 or 3 years are usually spent in

research, making fundamental measurements to

determine the feasibility of an idea. Another 2 years

are typically required to demonstrate the feasibility

of a process or equipment. Two more years are often

needed to develop a prototype, and as much as

another 2 to 3 years are frequently spent in so-called

“beta test sites” where the engineered hardware is

rigorously tested in a realistic environment.6 These

lengths of time are rough estimates and not absolute

rules that apply to every case. However, they are

consistent with the experience with TNA.

This process may be shortened somewhat, but

rarely to less than 5 years. The developmental time

depends on the urgency of the project, whether the

initial research is funded sufficiently to allow

concurrent approaches to solutions of problems, the

complexity of the hardware, and, most of all, the

relation of the hardware to other existing, preferably

commercial, equipment.

The time to produce a prototype can be reduced in

the case where only a minor rnodification of existing

commercial hardware, rather than a brand new class,

is required. Modifications of existing commercial

x-ray scanners fall into this category. Another major

advantage of modifying existing hardware is that the

manufacturing capability is likely to exist already.

To maximize the likelihood of success, long-term

research often must incorporate different avenues of

approach. In some cases, it may be advisable to back

different groups working on similar technologies.

Much basic research is a high-risk, high-payoff

procedure. Coupling high-risk research with

small studies that evaluate how a particular

technical approach would fit into an integrated

security system would be a useful approach in

guiding long-range funding decisions and in

determining which technologies to support. One

especially important topic to study would be the

definition of requirements for an integrated

system, as opposed to requirements for component devices.

The FAA is pursuing a dual-track program. On the

one hand, it is looking for devices that, while limited

in effectiveness, have the advantage of being avail-

%rhe final OTA report will discuss this issue in detail.

GFor a &scWsion of why it takes so long to field the results of government-funded R&D, see U.S. Congress, Office of Technology As~~ent,

Holding the Edge: Maintaining the Dejense Technology Base, O’DLISC-420 (Wkshingtoq DC: U.S. Government Printing Office, April 1989), ch. 8.
64 ● Technology Against Terrorism: The Federal Effort

able soon. On the other hand, it sponsors technology

that is not yet mature, but has the promise of

producing superior equipment in the long run. The

FAA’s funding has increased substantially in the last

2 years, as Congress has urged increased research

efforts in hopes of providing a near-term solution.

The FAA's work in sponsoring research appears

to be improving, in part due to increased funding,

which makes it possible to take more research risks.

But there is a need to decide with some firmness on

a date, preferably within 2 years, by which time

competing technologies for near-term application

should provide detectors to be tested in realistic

settings. This would allow the winnowing out of

unpromising lines of research. If testing is successful, a rule requiring widespread acquisition of the

detectors could be promulgated. This action would

presumably stimulate the market to produce more

competing instrumentation of the same type. If

testing in a given area is unsuccessful, this may

indicate that R&D should no longer be actively

supported along that particular direction.

If- such a restriction is not imposed on research

that is on the near-term track, there is a danger that

technologies may continue to develop, but without

ever producing workable prototypes. It is a cliche,

but true, that the better becomes the enemy of the

good.

One difficult task is to formulate a reasonable set

of performance standards to judge the products of

research. The standards will have to be acceptable to

Congress, as guardian of the public interest.7 If this

had been done in the TNA case, much controversy

and many political difficulties could have been

avoided. There are, however, problems in setting

standards, particularly for vapor detectors, because

the performance of the machines is so affectedly the

scenario in which they are used and, thus, a terrorist

scenario must be specified in order to set the

standards. Efforts have been made in developing

such scenarios, e.g., by the American Society for

Testing and Materials, but little in the way of

progress has yet been achieved. Nevertheless, a

logical basis for standards must be developed and set

so that credible testing and evaluation may begin.

Analysis is needed to determine how much effort

should be devoted to developing near-term solutions, how much to longer term technologies, and

how much to accelerating work on the more

promising longer term technologies so that they may

be developed more quickly.

FAA RULEMAKING FOR ●

EXPLOSIVES DETECTION

SYSTEMS

The FAA accepted a TNA prototype in fulfillment

of an R&D contract following a series of tests run in

1987 and 1988 at Los Angeles and San Francisco

Airports. These tests have been criticized by a

number of groups.8 They were not double-blind and

they used explosive simulants equivalent to the

amount then thought required to cause a large

commercial aircraft to crash. Unfortunately, after

Lockerbie, the world discovered that a much smaller

quantity could destroy an aircraft. Further, the

explosives were attached to the outside of test items

of luggage, not a likely geometric configuration to

be found in practice.9

As part of Public Law 101-45, which became

effective on June 30, 1989, Congress ordered FAA

to develop a rule that required:

. . . the use of explosive detection equipment that

meets minimum performance standards requiring

application of technology equivalent to or better than

thermal neutron analysis technology. . . as the Administrator determines that the installation and use of

such equipment is necessary to ensure the safety of

air commerce. The Administrator shall complete

these actions within sixty days of enactment of this

Act. . . .

The FAA then issued a proposed rule, published

in the Federal Register as a Notice of Proposed

Rulemaking, to amend part 108 of the Federal

7~e ~cflc dewpro~bly sho~d be kqt -tfrom the public to avoid tipping Off terrorists ils to the limi@tiOnS of the a~t~SYs-.

SForexample, seethe testimony of Ref. Lee Grodzius before the Presidential Commission on Airline Security and Terrorism, Washington DC, Feb.

9, 1990.

% is another serious defect, since the TNA system is supposed to “l-’ through an artificial intelligence technology Imown as “neuxal

networks,” to detect a bomb in a suitcase through experience in evaluating data (stimulated gamma ray counts horn the suitcase, together with the rough

location of the gamma rays’ origins) and comparing it with the knowledge of whether the suitcase actually had a simulated explosive or not. If the samples

on which the device learned were not ralistic, there would be no guarantee thag when inspecting realistically packed bags containing explosives, the

machine would have the same rate of detection or false alarms.
Chapter 5-Conclusions Regarding Current Research and Development Into Detection of Explosives ● 65

Aviation Regulations to require an explosives detection system (EDS) for screening checked baggage

(but not carry-on baggage) on international (but not

domestic) flights.10 Ironically, TNA might work

better for carry-on than for checked baggage

because the weight of carry-on luggage is generally less than the weight of checked luggage.

Thus, for carry-on luggage, the nitrogen signal

from the explosive would be easier to see above

the background from other nitrogen in the bag

than would be the case for checked luggage.

About half of recent successful airline bombings

have resulted from explosives placed in the passenger compartment, and half from explosives in the

cargo hold.

The EDS was supposed to alarm automatically.

This feature was designed to eliminate reliance on

security personnel for a rapid determination of what

was suspicious and what was not. Many security

personnel are not highly paid, trained, or motivated,

and reliance on their alertness under these constraints was not considered to be reasonable.

The Final Rule was published in early September

1989.

11 The FAA felt that it was feasible to

promulgate and enforce the rule since the tests at the

two airports showed that at least one technology was

available. In the discussion accompanying the Final

Rule, the FAA referred to TNA as “the only

existing, proven system. ’ The goal, as stated in the

Final Rule, was to require 860 such systems by 1999.

An alternative possibility was to install 200 within

3 years and 300 by 1999.

In further tests carried out at JFK Airport in New

York since September 1989, the TNA system has

performed significantly worse than in the earlier

tests. In addition to frequent calibration tests done

with simulated explosives on the outside of luggage,

the JFK tests are also occasionally performed with

explosives placed within bags taken from a set

belonging to the FAA for test purposes. This latter

test is claimed to have been carried out in a

double-blind manner.

Whereas detection probabilities of 95 percent

with false alarm rates of 5 percent were cited from

the earlier tests, more recent results quote significantly higher false alarm rates. Further, at least one

common explosive used by terrorists was not

simulated and used for testing the device. The

false alarm level was reduced by adding a two-beam

x-ray device to the equipment. However, the rate

was still high enough to clog airport operations, if

the device were to be used to screen every piece of

baggage.12 Automated decisionmaking was not used

for the x-ray part of the equipment. In any case, for

a Lockerbie-sized bomb, which was smaller than

equivalent explosive quantities used in the initial

tests, the detection rate is likely to be much worse,

or the false alarm rate higher (or both) than the

figures cited above.

Based on the testing results up to the present,

the TNA device by itself does not currently

appear to be an adequate system for screening

baggage at airports for small but deadly quantities of explosives. On the positive side, the experience gained by installing an explosives detector in

an operational environment has been extremely

valuable and has provided the FAA with important

lessons that will help in developing performance

criteria as well as evaluation standards and procedures for future EDS devices.

Attention should be given to developing means

(TNA-based or other) of screening carry-on

baggage. TNA may work better in this mode than

for checked baggage.

l~~e~ Register, 54, p. 28985, July 101989.

llFede~ R@s@, 54, p. 36938, Sept. 5, 1989.

l~t is diffictit to say without a detailed analysis what an acceptable false-alarrnrate would be. Some estimates, however, my be ~de. A f*-

rate of 5 percent is required by the FM rule. However, even this rate maybe marginal at busy airports, in that long queues maybe generated. A recent

study for the Air Transport Association gives support to this view (Practicability of ScrexmingInternational Checked Baggage forU.S. Airlines, Geoffrey

D. Gosling and MarkM. Han,wm, Institute of Transportation Studies University of California at Berkeley, UCB-ITS-RR-9&14, July 1990). As mentioned

in an earlier footnote, one foreign country has found it possible to operate if about 3 percent of checked baggage is carefully inspected, so a false-alarm

rate of this level would be tolerable”in at least some circumstances.
Appendix A

Nuclear-based Explosives Detection Systems

Thermal Neutron Analysis (TNA)

Sponsor:

Status:

Funding:

Federal Aviation Administration (FAA) Technical Center through contractual relationship

with Science Applications International Corp.

(SAIC).

Testing of one preproduction unit is under way

at JFK Airport, New York, one unit was

recently checked out in Miami, one is at Dunes,

one at Gatwick and two more are to be

delivered to FAA shortly for installation at

selected airports in the United States and

abroad.

$12 to $15 million R&D funding over 4 years

from FAA Technical Center, plus about $5

million private funding, plus $15 million for

the six preproduction units FAA bought for

airport demonstration.

Basic Operating Principle and Goals of Concept

When a neutron strikes a nucleus, there is a certain

probability that it will be absorbed. This process is often

accompanied by the emission of a high energy gamma ray

whose energy is characteristic of the nucleus. The amount

and type of some specific elements present in a sample

inspected by neutron radiation can be inferred from a

measurement of the intensity and energy of these gamma

rays. The TNA concept depends on this principle for the

identification of nitrogen in explosives.

An item of luggage is moved through a “bath” of

thermal (i.e., slow) neutrons generated by a radioactive

source or an electronic neutron generator (particle accelerator). In the current design, the isotope californium-252 is

used. The capture of a neutron in nitrogen results in a

high-energy gamma ray produced through the reaction

The signals from an array of gamma-ray detectors are

analyzed to give a rough spatial distribution of nitrogen.

Figure A-1 demonstrates the principle of operation of

TNA.

The currently tested version of TNA was designed,

following FAA performance specifications, to detect a

minimum mass of nitrogen, equivalent to a certain

quantity of plastic explosives. It has limited spatial

resolution and detects primarily nitrogen, not oxygen or

carbon; although hydrogen, chlorine, and some other

elements could, in principle, be detected to enhance

performance. Because only nitrogen is currently specified

by the device and because of the system’s difficulty in

dealing with nitrogen background from innocent materials, the false-alarm rate is higher than desired. This has

become an important issue for the current TNA hardware.

Further, the sensitivity (probability of detection for a

given quantity of explosives) is limited. Sensitivity can,

indeed, be increased by lowering thresholds, but a

concomitant rise in the false alarm rate results. This

situation can be improved, according to the system’s

designer, by using TNA or other techniques to measure

other elements present and by other system modifications.

Technical Description

The current TNA equipment is represented by engineered preproduction units that are being tested at airport

sites. They are being modified and upgraded in accordance with experience gained in a real operating environment. For instance, an x-ray system has been combined

within the TNA set-up in an attempt to reduce the false

alarm rate. The combined TNA/x-ray system is generally

referred to as the “XENIS’ system.

The californium source is of moderate strength (approximately 80 millicuries or 3 x 109 alpha particles/see

and 3.5 x 108 neutrons/sec l). It is contained in a small,

double-walled capsule of a common industrial design.

The capsule was exposed to a blast from a substantial

explosive charge and maintained its integrity. Radiation

from the shielded system, near its surface, has been

examined and found to be comparable to the natural

background level of radiation exposure. The environmental threat of the system has been assessed by the

Nuclear Regulatory Commission (NRC) and found to be

within Environmental Protection Agency and NRC exposure guidelines.

The source exposes baggage on a conveyor belt to a

“bath’ of neutrons inside a shielded cavity. The baggage

is surrounded by an array of gamma-ray detectors, which

send their data to a computer. The software, in turn,

transforms the data into” a spatial distribution, giving a

rough image of the nitrogen content of the object. The

system also records various other data used as input to

algorithms that distinguish objects that contain explosives

from “clean” ones. The details of the analysis algorithms

have not been examined by OTA. Generally speaking, the

system utilizes artificial intelligence techniques based on

neural networks and permit the system to learn from

experience. Many pieces of baggage, including both items

containing explosives and clean ones, are observed by the

1A c~e is 3.7x 1010 disktegratiom/sec

-67-
68 ● Technology Against Terrorism: The Federal Effort

Figure A-l—Sketch of Apparatus for Thermal Neutron Analysis of Nitrogen

Bath of thermal neutrons

A /

(Y xN 15 + 10.8 MeV ~

specifications. These tests were not done independently,

SOURCE: be Grodzins, 1990.

system in order to learn the distinguishing characteristics

of the “bad” objects.2 There is a continual upgrading

process in refining the decisionmaking algorithms. The

add-on x-ray system is used to reduce the number of false

alarms by determining whether the nitrogen image

(provided by TNA) overlaps with the two-dimensional

image of density (given by the two-view x-ray system

used). The details of the correlation of these data have not

yet been examined by OTA.

Status

The current version of the TNA device was developed

by SAIC under FAA Technical Center sponsorship during

the last 5 years. SAIC was selected by a competitive

procurement process in 1985. The current device was

designed to satisfy performance specifications set down

by FAA at that time. These demanded, among other

things, a baggage handling rate of 10 per minute (6

seconds per bag) and automated detection. The devices

were tested against these criteria at SAIC’s laboratories at

Santa Clara, CA, as well as at San Francisco (SFO) and

Los Angeles (LAX) Airports in 1987 and 1988, where the

system was accepted by the FAA as meeting these

but were designed and conducted jointly by the FAA and

SAIC, in the presence and with the concurrence of FAA

consultants. This test was performed somewhat in the

manner of some Department of Defense weapons acceptance tests, and there is currently considerable controversy over their significance.

Since that time, the FAA has ordered 6 preproduction

units from SAIC for actual airport testing at a cost of about

$15 million. This price includes SAIC’s participation in

operations, maintenance for 1 year, and installation,

including the x-ray adjunct. The last of these units are

scheduled to be delivered to the FAA when their

destinations are determined. Currently, three of these

units are operative, one at Trans World Airlines (TWA)

at JFK Airport in New York, one at Gatwick Airport, near

London, and one at United Airlines at Dunes Airport in

the Washington, DC area. A fourth is being refurbished

after a year’s operation at Miami International Airport at

Pan American Airways. The Kennedy system routinely

operates about 5 hours per day, during which time most

of the foreign flights leave New York. It examines about

2~c ~~~~elation ~gofi~ ~m b~~ on s~c*s lost luggage st~ke ~ter it wss mpWIti by tie experience gained at LDS Angeles ~d S~

Francisco airports. The system is currently using the experience it is gaining at various sites to refine its decisionmaking capability.
Appendix A--Nuclear-based Explosives Detection Systems . 69

350 bags per day, primarily the interline transfer bags

from other flights. This selection was based on logistic

considerations (i.e., where the system could be physically

placed in the TWA baggage handling area), and is the

limiting factor on the testing of the system’s throughput

capacity. The Miami system was located at a baggage

transfer point and the Gatwick and Dunes units are

located in the main concourse in front of the check-in

counters.

The system is tested daily against baggage containing

simulated explosives. Performance data are gathered from

these tests as well as from the false alarms of real

passenger luggage. The current false-alarm rate is running

higher than that achieved in the “acceptance” tests for the

“LAX distribution.’ The XENIS system uses a two-view

x-ray seamer system, built by EG&G Astrophysics

Division, in tandem with the TNA device. With this

combination, the false-alarm rate is lowered significantly.

Any bags that do not pass the TNA/XENIS system and are

still deemed suspicious, following a close examination of

the data by an operator, are turned over to TWA for further

action. It has been claimed by SAIC that by rerunning a

suspect bag, the false-alarm rate can be lowered to a very

few percent. However, SAIC also notes that this decreases

the probability of detection.

The algorithm by which the system either accepts or

rejects a given bag is still under development and is being

modified to include the x-ray information. In the current

operating version, the x-ray/TNA information match is

being performed outside of and independent of the TNA

analysis.

Potential and Shortcomings

The SAIC TNA is the first automated baggage inspection system and the only one that, in the view of the FAA,

meets present FAA guidelines. However, the degree to

which it meets these guidelines is very controversial. The

impartial testing of this baggage handling system is a

complex issue: many variables need to be considered.

Baggage differs among airports, flights, and seasons.

These differences have profound effects on system

performance. Explosives also differ greatly. Various

types present differing degrees of difficulty. Also, human

factors are involved in how the explosives are handled for

any test. Currently, there is no generally acceptable test

protocol that would allow the FAA to certify that a system

is “working properly”, although FAA contracted with

the Department of Energy’s Sandia National Laboratory

to propose one. The National Research Council is also

looking at this issue for the FAA.

The current TNA system also has several severe

shortcomings, including its high cost, which is currently

estimated to be $0.75 to $1.0 million per system

(depending on various assumptions including the savings

due to large-scale production). SAIC claims to be willing

and able to build 30 units per year, but so far has no

committed orders and currently plans to build only a few

beyond the past FAA purchase. The current system is

massive, weighing close to 14 tons and taking up a large

amount of real estate (the footprint for the TNA alone is

about 12 m

2

, and an additional equivalent area would be

needed to add an x-ray system and baggage diverter) in an

area where space is scarce and valuable. Considerable site

preparation was necessary for the JFK installation.

Further, the use of a radioactive source and the resulting

shielding requirements present an acceptance problem. If

an electronic neutron generator were used, the shielding

requirement would not be reduced. To date, foreign

acceptance of TNA systems has been difficult to achieve,

but there are active negotiations between the FAA and

some foreign airports for test systems, and, as noted, a

TNA unit has been installed at Gatwick, near London. 3

The limited sensitivity and the strong dependence of

the false-alarm rate on the lower limit set for detection is

one of the major issues that will determine the utility of

the current version of TNA. The sensitivity, in terms of

the detectable amount of explosive, was set by the FAA

prior to the Pan Am 103 incident at Lockerbie, which is

generally thought to have resulted from a substantially

lesser amount than the original FAA specification. 4 The

publicly available data taken to date on the issue of

threshold sensitivity v. false-alarm rate are sparse.5

3’IIM r~tion ~Pweisme appears to be one of perceptions; the facts do not appear to indicate a serious problem. The operators of the ‘rNA ~1

be shielded to levels that are acceptable for workplace exposure, as defined by Food and Drug Administration standards (at 1 foot from the system the

radiation level is less than the permissible levels allowed for home TV sets). Residual dose rates iiom the baggage are very Iow-O.03 microSv/hr at

the surface immediately after exposure. The radioactivity declines rapidly afterwards. For compariso~ a resident of Leadville, CO experiences an

exposure of 2.8 milliSv/yr, transcontinental airline crews experience 2.80 milliSv/yr in addition to exposures received from normal background (which

amount to about 1.5-3.0 milliSv/yr, depending on location), the average humanreceives 0.2 milliSv/yr from potassium in food. Eating one banana per

&y gives a dose of 0.8 microSv~. From these&@ it would appear that the danger from mdioactivity from TNA is not a real issue.

AHowever, there were seve~ c==myye- prior to ~ckerbie in which lesser ~ounts of explosive were introduced aboard the aircraft Cmhl

and produced significant damage and fatalities.

SAt anNAS s~posi~ on Airline Security and Explosives Detectio~ Feb. 26-27, 1!390, Dr. Gozani of SAIC reported that when the sensitivity wm

raised to maintain a 95 percent detection probability for this reduced amoun~ the false rdarm rate rose to a high level. Since the initial writing of this

report, a significant amount of new testing of the TNA/XENIS systems both at Santa Clara and at JFK has occurred. Some of these tests were run by

SAIC with FAA supervision and overview, some by the FM and the last set by a group of independent consultants hired by the FAA, headed by Dr.

Joseph Navarro of Wackenhut Securities Co., supported by representatives from Sandia National Laboratory, the National Institute for Standards and

Testing, and the University of Georgia.
70 Technology Against Terrorism: The Federal Effort

Although the SAIC TNA system is the only FM-

‘‘accepted’ explosives detector currently at the prototype

stage, there is considerable commercial interest in the

development of more advanced versions of TNA. The

FAA rule, requiring installation of an explosives detection system (EDS) at 40 U.S. airports over a 3-year period

following the issuance of a final ruling, creates considerable incentive to industry to compete with SAIC. At

approximately $1.0 million per unit, this would represent

a $200 to $300 million market over the next several years.

Several domestic and foreign firms (e.g., Gamma-metrics

of San Diego), experienced in building similar inspection

equipment, are seriously eyeing this market and are

engaged in active development work to define their

concepts, and SAIC is working to improve the performance of their system. It is possible that within a year or

two, several such systems may be available for certification, possibly with some advanced features or options.

Another aspect to consider is the potential for TNA as

a detector for explosives in carry-on baggage. Checked

bags contain nitrogen in widely ranging amounts. The

task of finding a small bomb against this varying

background is very challenging. It is necessary to use

information on the spatial distribution of nitrogen density

to reduce the false-alarm rate even to its current high level.

Since carry-on bags tend to have less mass than checked

bags, the background would usually be less and the

detection task easier. It would be useful to pursue this

option, especially because now, only x rays are used to

screen carry-on baggage, and it is extremely difficult,

even for highly trained experts, to find a bomb using only

standard x-ray images.6 Some preliminary studies have

been carried out on this problem by SAIC.

Fast Neutron Analysis (FNA)

Sponsor;

Status:

Funding:

FAA Technical Center is supporting some

work at SAIC; there is some commercial

development.

Pre-prototype development.

$600,000 from FAA to SAIC for basic feasibility demonstration and preliminary conceptual

design.

Basic Operating Principles of the Concept

As an improvement on TNA, more energetic neutrons

can be utilized to give more information. When the slow

neutron source of the TNA is replaced by a more energetic

one, the interaction of the energetic neutrons with the

nuclei of the elements in the object to be examined will

produce gamma rays at different energies, characteristic

of the elements, which can be detected and distinguished.

These are often more copiously produced and thus easier

to see above background than the gamma rays produced

by thermal neutron irradiation. For instance, 14-MeV

neutrons interacting with oxygen, carbon, and nitrogen

will produce 6.1, 4.4, and 5.1 MeV gamma rays respectively. Measurement of each of these separately (see

figure A-2) may yield a rough spatial distribution of the

three elements in a manner similar to the TNA system.

Technical Description

An FNA system is physically similar to the TNA

system, but there are significant differences in the source,

the shielding requirements, and the gamma-ray detection

arrays. A fast neutron source requires an accelerator, not

a radioactive source, and is thus significantly more

expensive from the beginning (at least by $250,000 and

probably considerably more). An FNA system will almost

certainly require more shielding than the TNA, representing another potential increase in cost, size, and weight.

Several different concepts of fast-neutron sources are

under development both in the United States and abroad

(notably France). Many more elements, most importantly

oxygen, can be measured by this technique.

Potential and Shortcomings

The obvious potential of the FNA is that it makes an

essentially unambiguous determination of the presence of

common explosives. It was shown in figure 4-4 that

common explosives display a nearly unique range of

nitrogen density to oxygen density. By being able to

measure both these quantities as well as carbon and

hydrogen density, FNA should greatly improve accurate

identification of a hidden threat.

On the other hand, an obvious shortcoming of the FNA

system is the use of fast neutrons. These neutrons create

a significant background in the gamma-ray detectors,

making it difficult to extract the information. The

feasibility of commercial use of such a source, its

shielding, and consequently, its operational restrictions in

an airport environment have yet to be established, though

a significant body of data from laboratories and from

bore-hole oil-well logging does exist.

Pulsed Fast Neutron Analysis (PFNA)

Sponsor: FAA Technical Center.

Status: Basic R&D and feasibility experiments in

progress under FAA sponsorship.

Funding: $220,000 from FAA to SAIC

G~e de~led r~~ts vw with mmy parameters, but several general characteristics are repeatedly seen. The following statements motid be kept ~

mind when considering TN~NIS test results:

. Detection Probability, P~, is generally given as a weighted average for a specitled selection (usually 5) of different explosives.

. When thresholds are reduced, false alarm rates rise rapidly.

Another adjunct to x rays for screening carry-on baggage could be advanced vapor detection systems, now just coming on the market.
Appendix A-- Nuclear-based Explosives Detection Systems . 71

Figure A-2-Sketch of Apparatus for Fast Neutron Analysis of Nitrogen, Carbon, and Oxygen

Bath of fast neutrons

~

/

4 ‘- --- -k ~--“ --e -

0’ -. -- - - --- - ----“:*L . . /..- -

\- -A-‘-‘- /“ - :::-- - --,’” 4----

/+- \?*8 ------ ‘ 1/

,,

14 MeV n + 0(16) ~

14 MeV n + C(12) ~

14 MeV n + N(14) ~

0(16)’ + 7.9 MeV n

\

0(16) + 6.1 MeV ?’

C(12)* + 9.6 MeV n

\

C(12) + 4.4 MeV Y

N(14)* + 8.9 MeV n

\

‘% N(14) + 5.1 MeV T

SOURCE: be Gradzins, 1990.

Basic Principles of Operation of the Concept

The PFNA concept is similar to the FNA system,

except that a pulsed beam of neutrons is utilized. A

focused, collimated beam is passed through the object,

resulting in the emission of gamma rays of specific

energies, characteristic of elemental constituents of the

sample. This method uses penetrating neutrons at lower

energies than in FNA. At these energies, the probability

for gamma-ray production by nuclear reactions with

oxygen, carbon, chlorine and nitrogen is about the same

as for 14 MeV neutrons; however, the gamma-ray

spectrum is cleaner and shows a much better signal-tonoise ratio. The gamma-rays are detected, as before, by

scintillators that provide gamma-ray energy information

by which the element can be identified. The neutron beam

profile provides the two-dimensional position information required to determine the spatial distribution. The

third dimension, derived by timing and image reconstruction, constitutes a significant improvement over the basic

FNA technique. A schematic view is shown in figure A-3.

Technical Description

Neutrons are generated

precisely timed bursts. The

by a pulsed accelerator in

arrival of the gamma-rays is

also accurately timed. The position of “interaction along

the neutron beam is determined using the time interval

between these pulses and the neutron speed, giving a third

dimension to the element density distribution.

The neutrons are generated by the deuteriumdeuterium (d-d) reaction and produced mainly in the

direction of the deuteron beam. The accelerator is larger

and more expensive than the deuterium-tritium (d-t)

neutron generators used in FNA, due to their higher

voltage.

preliminary studies have demonstrated the feasibility

of determiningg the position of the elemental constituents

of different samples. Better accuracy is expected with the

use of shorter duration deuteron beams and gamma-ray

detectors with better temporal resolution. Pulsed d-t

generators could also be used instead of continuously

operating ones with the main advantage of lower acceler-
72 ● Technology Against Terrorism: The Federal Effort

Figure A-3-Sketch of Apparatus for Pulsed Neutron Beam Analysis

1------>

//// Pulsed, neutron beams scanned from

/

y

bottom to top across the bag

SOURCE: I.se Grodzins, 1990.

ator cost, size, and weight. However, they present a poorer

signal-to-noise ratio and require heavier shielding.7

Potential and Shortcomings

The attraction of the PFNA system is its unambiguous

determination of the elemental composition characteristic

of explosives and the spatial information on the location

of these elemental concentrations. These features make

the PFNA a potentially powerful technique for explosives

detection.

To date, only the basic feasibility of PFNA has been

established. The R&D required for the construction of a

practical, collimated, pulsed energetic neutron beam,

however, is a technological problem, and the requirement

for making it safe and operationally acceptable, as well as

cost-effective, complicates the matter. The PFNA system

represents a considerable research and development

problem, likely requiring 3 to 5 years before its commercial utilization can be assessed. A thorough evaluation of

the operational issues of such a system should precede the

large expenditures-for cost, space, performance and

accelerator safety-that would be required to develop

such a system.

Nuclear Resonance Absorption (NRA) of

Sponsor;

Status:

Funding:

Gamma-Rays

FAA Technical Center is supporting research at

LANL and the Israel Atomic Energy Commission Nuclear Research Center at Soreq.

Feasibility experiments completed in Fall

1989, more research funding is likely.

About $l million in fiscal years 1988 and 1989;

requests for a program of $1 to $3 million per

year for the next 2 to 3 years are under

discussion.

Basic Operating Principles and

Goals of Concept

Physicists at the Soreq Nuclear Research Center of the

Israel Atomic Energy Commission proposed a scheme to

the FAA in 1986 in which the presence of nitrogen would

TThis description owes much to the comments of T. Gomti of s~c.
Appendix A--Nuclear-based Explosives Detection Systems ● 73

be detected by measuring the absorption of gamma rays

traversing a piece of baggage. The probability of absorption of the gamma rays of a particular energy by nitrogen

nuclei is very high. Scintillators would detect the transmitted gamma rays. A dip in the detected gamma rays

would indicate presence of nitrogen in the baggage.

The technique is derived from the existence of a narrow

state of excitation energy in 14N, resulting in a sharp

resonance of the cross section for the reaction 14N(Y,p)13C

producing a proton and a 13C nucleus. The gamma-ray

transition rate from the ground state of 14N to the excited

state is extraordinarily large. This means that gamma rays

of exactly the resonant energy are very strongly absorbed

by ordinary nitrogen nuclei, thus providing a unique and

clear signature of the presence of nitrogen, as opposed to

other elements.

The inverse reaction (protons on a target of 13C nuclei)

can be used to generate the probing beam of gamma rays,

resulting in gamma rays of just the right energy for the

subsequent resonance absorption. The effective size of the

source of these gamma rays can be made very small,

allowing an imaging capability. This technique has been

demonstrated to be capable of detecting nitrogen at levels

similar to FAA’s current requirements. Since the signature is unique and the gamma rays very penetrating, the

technique is impervious to attempts to avoid detection by

shielding the explosives.

Technical Description

The geometry of the NRA technique is very similar to

the familiar x-ray systems used at airports. However,

instead of a fan shaped beam of x rays, one uses a fan

shaped beam of gamma rays at precisely the right energy

to pass through the luggage (see figures A-4 and A-5).

A small electrostatic accelerator produces a proton

beam. When a beam of low energy protons, produced by

a small electrostatic accelerator, hits a 13C target, the

residual 14N is produced in the desired excited state. From

this state, high-energy gamma rays are produced the great

majority of the time (the balance being low-energy

gamma rays). At one particular angle with respect to the

proton beam, the energy of the gamma rays is exactly

what is required by the resonant absorption in nitrogen.

The beam spread depends primarily on the spread of

energy in the proton beam, the quality of its focusing, and

the thickness of the carbon target. The beam spread and

various other parameters of the apparatus have been

measured in the completed feasibility program to determine the practical performance limits of the concept.

In addition to the proton-beam/accelerator, the apparatus consists of a thin, cooled target and a detector array

aligned precisely to intercept the cone of gamma rays

which are emitted at the optimum angle. There are two

choices of detectors under consideration, resonant detectors favored by Soreq investigators and nonresonant

detectors proposed by a group from LANL that has

cooperated with the Soreq group in the program. Each of

the schemes has its advantages and disadvantages and a

clear choice is not obvious at this time. The nonresonant

detector is much more efficient and is commercially

available, but must sort out resonant absorption (specific

to nitrogen) from a nonspecific background. The resonant

detector needs developmental work, has lower inherent

efficiency, but produces a more unambiguous signal.

Measurements have been made, both with a nonresonant detector (a commercial BGO scintillator) and

with a resonant detector array. In both cases, luggage with

simulated explosives was passed through the beam of

gamma rays in front of the detectors. Images were formed

by computer reconstruction of the data from the detectors,

creating an array of pixels. The total nitrogen was

obtained by summing over all the pixels. When the total

nitrogen content was above some critical quantity, an

image was constructed to give the distribution and

location of the nitrogen. Explosive samples were detected

with very small amounts of nitrogen, either in blocks or

sheets and hidden within a radio. Impressive images of

simulated explosives have been obtained, using computer

image-enhancement techniques. The experiments that

were performed have been used to design potential

prototype systems that would be able to handle the FAA

requirements for an airport luggage inspection system.

Potential and Shortcomings

The NRA system may have considerable potential for

the FAA luggage explosive detection system (EDS)

mission. It appears to have the needed sensitivity and

spatial resolution and it measures nitrogen unambiguously. However, like the current version of TNA, it does

not measure anything but nitrogen.

The major choice that needs to be made at this time is

the level of investment in this technology and the program

emphasis for the immediate future. The question is,

should the program be aimed at demonstrating this

technology in the near term with a pre-prototype device,

based on currently available hardware, that can be

operated in an airport environment, or should the program

be aimed at assessing the ultimate potential of this system

(higher sensitivity with low false-alarm rate) in the long

term, or should money be made available for both?

Even if a major program based on this technology were

to be initiated, it would take about 2 years to demonstrate

the technology in the field and another 2 or 3 years before

an optimized system could be made available to the

airlines. At best, this could be cut to 3 years on a fast-track

high-risk (probably greater than about $10 million)

program, directed immediately at an advanced performance system.
74 ● Technology Against Terrorism: The Federal Effort

Figure A-4-Resonant Absorption of Gamma Rays

A

/’/ / /N;/, /

,//’ /’. / / /

Source of resonant

gamma rays

SOURCE: be Grodzins, 1990.

Sheet of resonant

rays

There are no good estimates of the cost, size, weight,

and operating parameters that could be expected from

such a system and a paper study aimed at determining

such parameters under various technology assumptions

could be valuable. In making a cost comparison with the

TNA system, the NRA’s accelerator will most probably

be significantly more expensive than the current isotopic

source for TNA. Some of this increased cost maybe made

up by less expensive shielding (since gamma rays are

easier to shield than neutrons, and the 1.747 MeV protons

have too low an energy to induce much radioactivity in the

apparatus) and a cheaper detector system. The resonant

absorption technique is one of the more promising

advanced technologies and such a study could quantify its

potential.

Associated Particle Production

Sponsor: FAA Technical Center—DOE at Los Alamos

National Laboratory, previously sponsored by

TSWG.

Status: Early Research.

Basic Operating Principles

The technique uses high energy (14 MeV) neutrons and

3 MeV alpha particles from a deuterium-tritium reaction.

The direction and timing of the alpha particles are
Appendix A--Nuclear-based Explosives Detection Systems . 75

Figure A-5-Resonant Absorption of Gamma Rays

II Cone of

9.172 MeV

resonant T rays

II

M/

[-E===V

I

n

Ii\\

l\

l\ Detector

1

SOURCE: Lee Grodzins, 1990.

measured to determine uniquely the direction and timing

of the neutrons. The timing and energy of the gamma rays

that result from the interaction of these neutrons with the

nuclei of the examined object are also measured. By

combining the gamma-ray data with the alpha-particle

and time-of-flight information, a three-dimensional mapping of the carbon, nitrogen, and oxygen in the baggage

may be obtained. The spatial resolution of this system

should be adequate to see small explosives.

This technique is another one that has the potential to

provide an unambiguous and spatial determination and,

consequently, should be highly effective for detection.

Preliminary experiments have been performed at LANL

with promising results, but fielding this technology would

not be likely for many years.

Nitrogen-13 Production-Positron Emission

Tomography

Sponsor: DARPA, in cooperation with Sandia National

Laboratories, supporting Titan Corp. (Spectron

Division).

Status:

Funding;

Funded demonstration program.

$2.83 million over three years, of which $1.78

million went to Titan from DARPA, and $1.05

million went to Titan from Sandia.

Basic Operating Principles:

In this technique, a gamma-ray beam activates the 14N

isotope 8 in explosives to an excited state of a radioactive

isotope of nitrogen (13N). A neutron is also emitted, which

is not important for this application. The reaction is:

gamma-ray + 14N = 13N* + n.

Following activation, the nitrogen-13 isotope decays with

a ten-minute half-life, emitting positrons (the positively

charged antiparticle of an electron). Each positron

immediately annihilates with an electron in the region,

producing two back-to-back 511-keV photons that are

detected by scintillation counters.

The gamma-ray beam is produced by a specifically

designed radio-frequency linear accelerator (RF-LINAC).

81U m~e, over w percent of nitrogen exists ss the isotope 14N with the balance befig 15N.
76 ● Technology Against Terrorism: The Federal Effort

The accelerator first produces an electron beam of about

14 MeV energy. The electrons then strike a tantalum or

tungsten target and produce gamma radiation with a

maximum energy equal to that of the electron beam. The

gamma rays interact with explosives and activate the

nitrogen via the above photonuclear reaction.

One advantage of this approach is that, by tracing back

the paths of the two 511-keV photons, one can achieve

excellent spatial resolution, perhaps on the order of a

centimeter or so in each dimension.9 The ability to image

will be vital in order to eliminate background coming

from those few isotopes that might confuse the picture.10

A final assessment on how well this system can get rid of

background awaits the testing of a prototype.

One of the features of this system is that, because of the

10-minute half-life of the radioactive nitrogen isotope, the

irradiation and detection stations can be separated,

reducing background problems and simplifying detection. Further, it is easy to have multiple detector stations

for each radiation source (the accelerator). It is proposed

to use this system in tandem with standard x-ray seaming

or tomography equipment to achieve high resolution.

Status

This technique, designated by the vendor as Explosive

Detection Using Energetic Photons (EXDEP), has been

experimentally checked in the laboratory for detection of

buried mines. A demonstration system is currently under

construction at Titan for testing in realistic situations. An

aggressive program aimed at the FAA mission would

probably require about 3 to 4 years, and $5 to $10 million.

As with other energetic particle beam concepts, the

accelerator, its cost, size, and shielding requirements are

major issues.

Pulsed Neutron Backscatter (PNB)

Sponsor;

Status:

Funding:

Commercial development to date by PENETRON, InC.

Some laboratory measurements made to verify

concept

Proposal submitted to FAA under Broad

Agency Announcement.

Basic Operating Principles

The PNB concept is based on the fact that fast neutrons

will interact frequently with light nuclei by elastic

collisions (roughly equivalent to billiard balls bouncing

off each other). Since the collisions are elastic, there is no

change in the structure of the nucleus; rather, the neutrons

scatter in particular directions with unique reduced energy

determined by the mass of the nucleus hit. Thus, by

measuring the energy of the scattered neutrons, the

nucleus that had been struck can be identified.

Two physical phenomena are used to detect and

analyze remotely concealed substances, such as explosives and narcotics. One is Neutron Elastic Back Scatter

(NEBS) and the other is Neutron Resonant Elastic Scatter

NRES).

In NEBS, carbon, oxygen, and nitrogen all produce

different back-scatter velocities. The intensity of the

back-scattered signals contains information on the

amounts of an element present, while the ratios between

the signals from various elemental nuclei scatterers

indicate the chemical composition of the substance. The

system is optimized for explosives by its choice of energy.

The back-scattered neutron energy is measured by a

large array of detectors using the neutrons’ “time of

flight” (i.e., the time of arrival of the neutron allows the

device to infer the velocity, which is simply related to its

energy). The measured energy spectrum then produces

characteristic peaks for the specific elemental nuclei.

From a knowledge of the elastic back-scatter cross

sections at a given energy and the relative height of the

peaks, the ratios of the elements are determined. Explosives have unique ratios among their carbon, nitrogen, and

oxygen quantities. These are signatures” by which they

can be distinguished from other materials. Access from

only one side is needed to carry out the examination.

In NRES, the incident neutron energy is varied first to

excite a resonance peak due to nitrogen, and then to a

nonresonant energy. Both energies are in a region where

there are no resonances for either carbon or oxygen. The

use of a resonant technique to highlight the signals from

nitrogen while retaining carbon and oxygen signals has

been demonstrated. Two complementary and simultaneous techniques would then be used to identify target

elements; in combination, high detection probabilities

and low false-alarm rates may be feasible.

The system has some limited capability of separating

signals from different locations along the path of the

neutrons. Signals from different depths will produce

smearing of the time-of-flight spectrum. Time-gating of

the arriving neutrons should produce depth measurements

as well as sharpen the spectrum. The ability to separate

these signals has yet to be established experimentally, but

PENETRON claims that analysis shows that separation

should be achievable.

% the related medical technique of positron emission tomography, resolutions on the order of millimeters are achieved. In the case of explosive

detection in baggage using the proposed system thick NaI crystal detectors, which limit spatial resolution, will be needed for high efllciency.

l%e developers propose to couple this technique with an x-ray system that would give a second resolved image tO tid hl diSWShhlgbem~

nitrogen and the sources of background.
Appendix A--Nuclear-based Explosives Detection Systems ● 77

Laboratory measurements have been made utilizing a

Van de Graaff accelerator at the University of Kentucky,

with typical materials characteristic of explosives, narcotics, and several common materials indicating promising

results. A definitive proof-of-concept demonstration requires the use of a dedicated facility.

Status

Promising laboratory experiments have been performed to verify the proposed scheme. A proof-ofconcept program is needed to determine the difficulty of

making the required measurements in a realistic material,

in which different substances are mixed. This concept

uses relatively low-energy neutrons and, consequently,

the shielding requirement would be moderate. The

accelerator technology also appears to be within sight. It

is claimed that this technology should be amenable to

extrapolation to the large cargo container problem encountered in freight hauling.

This concept is covered by several patents issued to Dr.

Henry Gomberg and Dr. Marcus McEllistrem. The

patents are assigned to PENETRON, Inc., a joint venture

of Ann Arbor Nuclear, Inc. and the Environmental

Research Institute of Michigan.
Appendix B

X-Ray-Based Detection Systems

Sponsor:

Status:

Funding:

Standard X-Ray Scanners

Commercially developed and available from

several vendors, such as EG&G Astrophysics,

Siemens-Heimann, and American Science &

Engineering (AS&E).

In serial production, both domestically and

abroad.

Developed through private funding. Unit cost

approximately $20,000 to $40,000.

Basic Operating Principles

The standard airport hand-baggage scanner has a

fan-shaped or scanning x-ray beam that is transmitted

through the object to be inspected. The absorption of

x-rays is usually measured by a line of detectors, and a

high-resolution image, derived from the degree of absorption of the beam, is produced. The image depends

primarily on the density of objects located in the bag along

the beam of the x-ray. These devices cannot distinguish

between a thin sheet of a strong absorber, such as a metal,

and a thick slab of a weak absorber. Simple x-ray systems

rely on humans to serve as pattern recognition devices; in

the absence of advanced computer pattern recognition

techniques, they are very dependent on human factors,

i.e., the training and quality of the observer.

X-ray scanners come in single- or two-view versions,

with the two views being orthogonal. X-ray scanners

present their images in shades of gray (as many as 80

shades depending on the degree of absorption), or in

“pseudo-color,” where colors are used to produce an

artificially enhanced visual presentation.

Dual- or Multi-energy Scanners

Sponsor:

Status:

Funding:

Commercially developed by several vendors.

Commercially available. Several vendors

make such equipment, such as SiemensHeimann, and EG&G Astrophysics.

Commercially developed, unit cost less than

$1OO,OOO.

Basic Operating Principles

Dual-energy systems are really two x-ray systems,

whose beams are generated by sources that peak at

different energies, producing two independent pictures.

The higher energy view suffers less absorption. While

areas of heavy elements are dark in both views, areas of

light elements are darker in the lower energy view. By

comparing both images, light elements such as carbon,

nitrogen, and oxygen may be emphasized. In this way, it

is possible to determine whether a given object is made of

a light or a heavy element.

Multi-energy systems are essentially the same except

that they have a single x-ray tube that transmits a broad

spectrum of energies. Detectors are used to select specific

energy regions. Both systems produce effectively the

same result.

Technical Description

This technique cannot distinguish among the light

elements (e.g., tell nitrogen from oxygen from carbon).

However, it can overcome the countermeasure of hiding

explosives behind an object made of a heavy element

(unless enough material is present to absorb the entire

beam-corresponding to approximately 8 to 10 mm of

steel), which standard x-ray scanners cannot.

These devices are technically identical to simple x-ray

scanners, except for the dual energy and image feature.

The systems use color to separate the image into organic

(light elements), inorganic (usually heavy elements), and

opaque materials (a lot of heavy element matter). For

instance, the EG&G E-Scan system assigns the color

orange to organic materials, which might include explosives. Some proponents believe that this use of color is a

big help to an operator’s ability to detect explosives.

Sponsor:

Status:

Funding:

Backscatter X-Rays

Commercially developed by AS&E.

Commercially available from AS&E. Computer algorithm currently under development

for automatic detection of explosives.

The Model 1012/10122 systems are available

for $60,000 to $100,000 per unit either as a

single (101Z) or dual (101ZZ) view system.

Basic Operating Principle

The AS&E backscatter system scans a pencil beam of

x-rays across the object and makes two images: the

normal transmission image, created by a single detector

on the opposite side, and a backcatter image, created by

a large area detector on the side of the entering beam. A

single energy x-ray beam is utilized. A two-sided version

of this system with two identical x-ray beam systems

makes backscatter measurements from opposite sides of

the object to enhance the backscatter penetration capability of the system.

The transmitted beam provides a typical x-ray image

showing primarily the absorption by heavy elements. The

–78–
Appendix B--X-Ray-Based Detection Systems ● 79

backscatter signal intensity depends on how much of the

transmitted beam has been absorbed, how much is

backscattered, and how many of the backscattered x-rays

reach the backscatter detectors. The backscatter signal

depends on the competition between photoelectric absorption and Compton scattering. The photoelectric cross

section increases with the atomic number of the object z,

while the Compton cross section is relatively independent

of atomic number. Therefore, the resulting backscatter

signal favors the low Z elements, with particular emphasis

on low Z elements of high density, such as plastic

explosives. Backscatter imaging provides a direct measure of the density of elements with low atomic number.

Technical Description

The AS&E system produces two independent x-ray

images: an x-ray transmission image emphasizing the

high Z elements, and an x-ray backscatter image emphasizing the low Z elements. The system utilizes a proprietary Flying Spot technique, which sweeps a small pencil

beam of x rays across the object to generate each line of

image data.

A single large solid-state. transmission detector measures the x-ray absorption by integrating the detected x-ray

flux over time. The Flying Spot scanning beam technology is required for efficient scatter imaging. Because only

one small area is illuminated by the pencil beam at any

instant of time, all detectable backscatter must come from

that pixel. A large solid-state detector measures the

backscattered x-ray signal, again with time integration of

the detected backscattered flux. By comparing the two

images, the operator can make judgments about the

composition of regions of high density, which may help

detect and identify threatening contents of a bag.

Currently, AS&E is implementing a computer algorithm for automatic detection of explosives with the aim

of achieving a high probability of detection and a low

false alarm rate for explosives. The automatic detection

scheme is based on an algorithm that compares properties

of object bag images against acceptable thresholds. The

system builds a database of acceptable histograms by

observing and “learning” the characteristics of a large

variety of bags. An algorithm sorts and combines the data

for online comparison with acceptable values. The AS&E

system “learns” the characteristics of bags in a manner

similar to the learning part of the TNA system.

Potential and Shortcomings

Implementation of the automatic detection algorithm

has proceeded slowly in the past, supported only by

company funding. However, the FAA has recently funded

the completion of development and initial field testing of

this system. Field testing is scheduled to begin within a

few months. Although the automatic detection of simulated explosives has been demonstrated, to date there have

been no definitive field tests of the effectiveness of the

system. If this scheme is successful, it will be easy to

retrofit to existing AS&E systems. The company states it

can produce these systems at a rate of about 200 to 300 per

year.

Computerized Tomography (CT)

Sponsor:

Status:

Funding:

X-Ray Scanners

Commercial development with some support

from the Army and FAA

Pre-prototype system demonstrated by Imatron, Inc. to FAA in June 1989; Imatron claims

a prototype is being readied for airport testing

in the near future.

The cost of these systems will probably be of

the order of $500,000 to $600,000.

Basic Operating Principles

This system is an adaptation of a compact, fast, mobile

medical CT scanner, which Imatron has developed for the

U.S. Amy. This concept utilizes a conventional x-ray

scan projection to locate areas with sufficient density to

represent a threat. In addition, multiple detectors, placed

on a rotating circumferential element around the object,

measure the transmitted signal from a fan beam that

traverses it (as in standard CT devices). The density at

each location along the path of the beam can be

determined, with the rotating action giving the information to provide a complete two-dimensional slice. The

inspected object is moved through the detector/beam

station by means of a conveyor belt, providing the third

dimension, i.e., multiple slices, for an image that then can

be viewed from all angles by computer projection

techniques. This technique also has very good spatial

resolution (a few millimeters).

Technical Description

This system operates and looks very much like the

medical CAT (computerized axial tomograpy) scanner

from which it was developed. Imatron’s niche in the

medical CAT scan business is the field of very fast

scanners, as well as portable systems designed for army

field use. The explosive detection device was adapted

from this work.

The system first produces an x-ray scan similar to the

conventional airport x-ray scanner. An automated inspection algorithm determines the locations within the baggage where the absorption indicates a suspicious area;

cross-section CT slices then need to be made to determine

the density, texture, mass and shape of the object.

Dual-energy CT, a theoretically possible, although not yet

implemented option, would also provide information on
80 ● Technology Against Terrorism: The Federal Effort

atomic number. If no high-density areas are detected, a

single slice through the bag is made to look for any sheet

explosives that may not have been seen in the projection

scan. Since the CT scan produces true cross section slices,

it is able to identify objects that are surrounded by other

materials or hidden by innocuous objects. When alarms

are encountered, the CT Scan operator can make further

slices to reveal size, shape, mass and make-up of the

suspect object. Three dimensional rendering may also be

applied.

The Imatron CTX 5000 uses color coding to highlight

possible explosives. The spatial resolution may be good

enough to locate wires, detonators, or related bomb

components.

Potential and Shortcomings

The current claim for throughput is 360 bags/hour,

which is too slow for current FAA requirements. This

throughput is calculated assuming an average of 2.5 slices

per bag. Only field experience can establish what the real

requirements will be. Since this limit derives from limits

on speed of computation, it is possible that future

computer improvements (which are coming very rapidly)

will sufficiently increase the speed of the system. The

current aperture diameter is 63 cm, which is too small for

some bags. Future versions will have an 80-cm diameter

aperture, according to the vendor. The ability to resolve

explosives using only density information was investigated at LAX by CT scans of 900 checked bags and 100

bags with simulated explosives in a FAA sponsored test

in 1988. The results were encouraging to the vendor.

However, more precise data, including detection probabilities, false alarm rates, and throughput will have to be

determined through more extensive tests. Unit cost is

estimated by the vendor to be around $500,000 to

$600,000.
Appendix C

Vapor Detection Systems

Sponsor:

Status:

Funding:

Gas Chromatography With

Chemiluminescence

Federal Aviation Administration (FAA) Technical Center; Department of State; both supporting contracts with Thermedics, Inc.

Hand-held unit is in production for U.S.

Department of State and other buyers. Prototype for “walk-in” style of detector for airport

concourse security is being built for FAA but

is not yet formally tested.

Approximately $7 million from the Department of State since 1985 and approximately $5

million from the FAA since 1984, plus some

private funding ($6 million) from Thermo

Electron Corp., the parent of Thermedics.

Basic Operating Principle and Goals of Concept

These devices use gas chromatography, a fully mature

technology, to separate a sample of molecules from a

carrier gas and to isolate molecules of different chemical

compounds from each other. The sample is taken with a

portable hand-held collection unit that heats up the

sampled surface with infrared lamps and sucks air from

near the surface.l Heating is important, since vapor

pressure increases by a factor of 10 for every increase of

10 ‘c.

The sample is then injected into chromatographic

columns, which consist of thin tubes lined with a material

that absorbs or dissolves the molecules of interest, thereby

retarding their passage through the column. Different

molecules are slowed to different degrees. The material

with the least affinity for the column substrate will go

through fastest and those with increasing affinity will

traverse the column in longer times. Residence time

within the column can be adjusted by varying such factors

as column length and temperature. Furthermore, since

different materials are released from the column at

different times, this technique allows mixtures of material

to be resolved. With proper calibration, the residence time

of a given type of molecule within a given column is

predictable and can be used to identify the molecule.

At the termination of the separation process, column

contents are heated to pyrolyze the explosive compounds

into fragments, among them nitric oxide (NO). The

chemiluminescent reaction of nitric oxide with ozone (O3)

is well known2 and yields photons that can be detected by

conventional means3. This signal is analyzed by a

microprocessor to determine if it meets predetermined

criteria for alarm. The timing of photon detection can be

used to identify those explosive compounds present, since

each compound has a characteristic speed of migration

through the column.

While this strategy relies on familiar instruments and

well-known chemical reactions, it is by no means an

insignificant task to perfect the operational parameters so

that minute quantities of material can be successfully and

reliably recognized within a few seconds. Through a

proprietary combination of column lengths and temperature cycles, the manufacturer of this device, Thermedics

Inc. of Woburn, MA, claims to be able to detect plastic

explosives rapidly. Independent tests have also shown

that the device has this capability. The company also ran

tests that appear to show that their walk-in booth, based

on the same technology, responds to plastic explosives

hidden under one layer of clothing.

Technical Description

The only difference between the hand-held and walk-in

models is the sample collection step. In the walk-in

device, an individual to be tested stands in a booth where

air is vigorously blowing. The velocity of the air is

sufficient to cause at least the outer layer of clothing to be

agitated. Simultaneously, the subject’s skin and clothing

are warmed by infrared heaters. This facilitates the escape

of any target molecules. The air currents are collected

through a series of funnels positioned in a vertical array

in the back of the booth.

The hand-held device consists of two units: a testing

unit and a collector. The testing unit is about the size of

a 55-gallon drum and contains the chromatographic

columns, chemiluminescent reaction chamber, and all the

display instrumentation. The collector, which is about the

size of a large hand-held vacuum cleaner, contains a

suction device and is adapted to be placed against or near

an object to be tested. The head of the collector unit

includes a heat source and appropriate ducting to direct

the resulting air stream onto a preconcentrator. This unit

consists of a high surface area substrate made of a material

onto which active molecules (which would include any

explosives) in the air stream attach themselves while inert

materials are blown past. At appropriate intervals, molel~e walk-in portal unit ~ples quite differently and is discussed separately. Except for the sampling, the two units are eSSen~ytie sine.

2P.N. ~OU@ and BA. Thr& “Mechanism of Cbemilumine scent Reaction Between Nitric Oxide and Ozone,” Trans. Faru&zy Soc., 63,915 (1967).

3SCZ U.S. patent No. 3,763,877 issued Oct. 9, 1973 entitled “Fluid Flow COntIOl System.”

–81–

292-884 0 - 91 -- 4 : QL 3
82 ● Technology Against Terrorism: The Federal Effort

cules are released by warming the preconcentrating

device. For the hand-held device, this operation is

performed after the device has been clamped into the

testing unit.

The expelled gases pass through a series of chromatographic columns specially designed to facilitate separation of the target molecules from the carrier gas and from

each other. The chemiluminescent reaction is performed

on the columns’ effluents. Lights on the operator’s panel

indicate which, if any, explosive has been sensed. A more

informative display is also available in the form of a video

monitor, which shows the chromatogram (a chart on

which the time of arrival for each compound appears as

a peak) as well as a hard copy from a thermal printer.

Potential and Shortcomings

Opinions on the merits of this device vary considerably

with the customer. This device is one of the few sniffers

on the market that claims to be able to detect pure plastic

explosives. In a maintenance-plagued test of a prototype

device conducted on real luggage in February 1989, the

FAA reported that the hand-held system did not perform

well. 4 However, more recent tests, both in the United

States and abroad, including some in an airport environment, have produced far better results. Further FAA

testing has been done, but the results have not yet been

released.

The experience of the State Department has been far

more positive. The State Department was interested in a

different set of criteria than was the FAA. High throughput was not as important in the State Department’s

application as it is in an airport environment. State was

also willing to accept a higher percentage of false

positives because the inconveniences associated with

such readings were less serious for their purposes. They

wanted a device that could be easily operated by

technically unsophisticated foreign nationals. For these

reasons they were attracted to the Thermedics products.

Tests conducted for the State Department showed certain

maintenance problems (apparently resolved now) but

confirmed the sensitivity of the device to plastic explosives and concluded that the device had promise. One

foreign country, investigating this device for purposes

and using methods not originally envisioned by the

manufacturer, has reported very favorably on its performance. In December of 1989, they were given the use of a

Thermedics machine for a few weeks and they proceeded

to try it out in every possible environment: airports,

harbors, border crossings, and post-blast forensic work.

They were impressed with the machine’s ability (unique,

in their opinion, among the “sniffers” they had tested) to

respond accurately to the plastic explosives. They found

the machine insufficiently rugged, in its current state of

engineering, and too slow to operate effectively in a high

throughput situation such as the baggage area of an

airport. However, significant improvements have recently

been achieved and field testing within the past year has

shown far superior performance with respect to maintenance and operation. The ability of this device to identify

an explosive was superior to that of other analytical

techniques now used. Several other countries have also

tested this device, and a number of foreign sales have been

made, some for airport use.

The hand-held device is in commercial production and

sells for about $150,000 (including an extra chemistry

module) under the tradename EGIS II.

The device operates remarkably quickly for a gas

chromatography. The gas traverses the chromatographic

column very quickly and subsequent signal analysis can

be completed in about 30 seconds. Some customers find

this speed acceptable, but current performance of the

walk-in booth (due to slow sample collection time) would

not meet FAA concourse throughput requirements unless

several units were operated in parallel, or a completely

independent prescreening technique were used, or unless

several individuals were scanned at the same time.

Because it is capable of identifying which explosive

compound has been detected, this system is very useful

for post-blast forensic investigations. Some tests have

also shown an increased effectiveness using the wipedown technique: wiping a suspect objector person with

a paper cloth, and then sampling the cloth.

Information on the current sensitivity of this device to

interferants and false alarms was not available, although

tests on earlier units found false alarms due to local

contamination to be a problem. The manufacturer asserts

that the current production devices have very low

susceptibility to interferants. Another problem might be

that the chemiluminescent reaction is reported to be not

particularly sensitive. However, the sampling and collection of these machines is very efficient. Furthermore, the

technique is quite selective relative to other vapor

detection techniques, allowing the detector to operate at

sensitivities that appear to be competitive with these other

methods.

A~e manufac~er claims that this test is not representative Of the perfo rmance of tbis device and that the current model performs better. Furtber,

some problems were claimed, also by the manufacturer, to be due to cross-contamination in the FAA’s laboratory rather tban to the machine’s

performance.
Appendix C—Vapor Detection Systems ● 83

Gas Chromatography With Electron Capture

Sponsor:

Status:

Funding:

Detector (GC/ECD)

FAA

U.S. Navy

Canadian Government (for development work

by Canadian firms)

Workable machines are in production by several manufacturers; R&D is being done to

improve selectivity and trapping, to expand the

range of explosives to which the device is

sensitive, and to develop improved walkthrough device.

About $1 million over the last 3 years.

Basic Operating Principles and Goals of Concept

This equipment tests for low volatility, high electronegativity substances. Like the chemiluminescence device described above, these machines also make use of a

chromatographic column as a first step to physically

separate explosive molecules from other components of

a gas stream. The detector, however, is quite different. A

small radioactive source ionizes a gas mixture to form free

electrons that flow towards an anode, thereby creating a

constant current. Molecules emerging from the column

are mixed with these electrons. Being quite electronegative, the explosive molecules will “grab” some of the

electrons. Fewer electrons will then be available to flow

towards the anode, and this effect is sensed as a decrease

in the current. Microprocessors analyze this change to

determine if it meets predetermined criteria for an alarm.

Several configurations of this detection strategy are

commercially available and have found wide use throughout the world.

Technical Description

In a typical electron capture device--for instance, the

Ion Track Instruments Model 97—an air sample is

aspirated into the detector and impinges on a membrane.

Air and many contaminants (most critically, oxygen,

halogens, and water vapor, which would foul up the

detector downstream) are thereby separated from the

molecules of interest, which diffuse across the membrane

into a stream of argon gas. This stream is then directed

into a pair of chromatographic columns. This device,

however, uses two parallel GC columns, one coated with

a chromatographic substrate known to retard polar

(electronegative) materials such as explosives compounds and the other coated with a nonpolar substrate.

In the electron capture detector, the effluent from each

of the chromatographic columns-which contains argon

gas—is piped into one of a pair of detectors where it is

irradiated with beta particles from a small radioactive

source to yield a plasma containing Ar+ and electrons. The

electrons flow towards an anode, creating a measurable

current. If highly electronegative explosive molecules are

present, they will combine with some of the electrons to

form negative anions, thereby depleting the available

stock of electrons. This depletion is manifested as a

decrease in current. If there is no change in current, or if

a change occurs simultaneously in both detectors, no

alarm is sounded. However, if a substance is delayed by

the polar chromatographic column, the detector attached

to this column will react later than the detector from the

nonpolar column. If this delay occurs within a preset time

window (typically 10 milliseconds or so) and other signal

criteria (that vary with equipment design) are met, an

alarm occurs.

Other manufacturers employ variations of this strategy.

For example, a wad of adsorbent material maybe used in

place of the membrane to separate sample molecules from

the air stream. Another variation uses a single GC column

attached to a single ECD. A microprocessor decides

whether the timing and other characteristics of the signal

are indicative of the presence of an explosive. The

Canadian firm, Scintrex, is now marketing a dual-column

device; one column is designed to respond to the

EGDN-based explosives and the other to the NG/DNT

group.

These devices are available either as hand-held units or

as walk-through models. For example, the hand-held ITT

Model 97 has been on the market since 1978 and currently

costs about $15,000. The walk-through version of this

device is sold by ITT under the tradename EntryScan for

about $30,000. Other GC/ECD products include the

EVD-1 manufactured by Scintrex (selling price for the

dual column model, widely acclaimed for its ability to

sense EGDN reliably, is about $45,000) and Scanex Jr.

from Sentex Sensing Technology of Ridgefield, NJ.

Potential and Shortcomings

The commercial models of these devices were among

those tested by the FBI in their 1988 experiments. In

general, they all sensed the higher vapor pressure

compounds but were unable to detect the plastics and

other very low volatility materials.

While ITI claims to have detected SEMTEX with their

Model 97 device, most observers feel that the device was

actually responding to a contaminant (which does not

appear to be reliably present in the material) rather than to

the explosive itself. ITI asserts that all SEMTEX tested on

the detector has shown presence of contaminants, which

it states are unavoidable residues from the manufacturing

process. Not all experts agree, however. ITI also claims

sensitivity to Detasheet (although their detector, like the

other units tested by the FBI, failed to respond consistently to this material under field conditions) and, to some

degree, to U.S.-manufactured C-4. ITI claims that an
84 ● Technology Against Terrorism: The Federal Effort

upgraded version has improved detection capability for

plastic high explosives.

In the FBI test, vulnerability to interferants varied

among the detectors and apparently was related to the fine

points of the preconcentration and signal processing

subsystems. In the field, maintenance remains a problem.

Apparently the need to deal with an inert gas bottle, a

characteristic of all ECD devices, has been a problem, as

has fouling by airborne particulate matter. The response

time of some of these devices can be fairly slow (on the

order of minutes) although others, such as the ITI 97, have

a response time of less that 2 seconds. Some require a

prolonged (i.e., 20 minutes) warm-up time.

Current work is aimed at improving trapping techniques to be used upstream of the ECD. In work

performed for the U.S. Navy, ITI has experimented with

a batch mode of operation in which the membrane is kept

at a low temperature, under which conditions it functions

not just as a separator but also as a preconcentrator.

Recent tests of this device show promise.

Other experimental work is aimed at developing a

so-called rotary trap. This is a constantly rotating, circular

plate having a glassy adsorption layer. Sample air is

drawn through the plate at one location. At a second

location, the plate is heated to release the entrapped

molecules. Additional work is being done to improve a

walk-through version of this device.

Ion Mobility Spectrometry (IMS)

Sponsor: Technology is commercially available. Some

work is being sponsored by the FBI and by the

Canadian government.

Status: Commercially available under the Graseby

trademark; marketed in the United States by

Astrophysics Research Corp. of Long Beach,

CA (now, EG&G Astrophysics). Similar technology is used in units marketed by Barringer,

Inc. of Canada, through its U.S. subsidiary.

Funding: About $100,000 over fiscal years 1989 and

1990.

Basic Operating Principles and Goals of Concept

Air containing vapor or a stream of airborne particles

from an area to be tested is drawn in through a sampling

probe. Air and explosive molecules diffuse through a

membrane or a filter into a chamber where a sealed 63Ni

radioactive source ionizes the sample. Periodically (about

50 times per second), small bursts of ions are released into

a separation region by an electronic gating grid. Under the

influence of an electric field, these ions move down a drift

tube against the flow of a separation gas. The speed with

which these ions move through the tube is a function of

their mass, their charge, their physical shape, and the

amount of diffusion (deviation from a straight-line path).

Heavier ions, such as those of explosives compounds,

tend to travel more slowly than lighter, simpler ones

typical of air. The drift region terminates in a collector

electrode. Ions reaching this collector will cause a small

current peak. The position (in time) and magnitude of this

peak are analyzed by a microprocessor in order to

determine the identity and concentration of the vapor

being detected.

Potential and Shortcomings

In the course of the FBI test, this device operated with

about the same reliability and sensitivity as the other

vapor detectors examined (which were all GC/ECD

devices). The machine was able to detect the higher vapor

pressure explosives, nitroglycerine and DNT, but did not

respond to the lower vapor pressure materials such as

TNT or RDX. It was slightly more susceptible to false

alarm than the other devices. Like the others, it was unable

to reliably detect explosive threats in simulated real life

situations.

FAA sources note that these machines operate at

thermal equilibrium: the ions created by the radioactive

source stay close enough together for along enough time

to allow numerous molecule-molecule interactions. This

can cause scrambling, whereby the ionized explosive

molecules collide with other molecules and in so doing,

give up their extra electrons. Such de-ionized particles

would not be sensed by the machine. Also, due to the duty

cycle of the grid, 99.9 percent or more of the explosive

molecules never reach the detector. Given initial quantities of materials in the pico- or femtogram range, such

losses can be devastating to sensitivity. Finally, even the

sales literature for these machines indicates that accuracy

is dependent on the training of the operator.

On the plus side, however, several groups see promise

in an improved version of this device. Work at Sandia

National Laboratory has established that under ideal

conditions an IMS detector can find plastic explosives,

being sensitive to as little as 30 femtograms of explosive,

despite the built-in 103 to 104 losses caused by the duty

cycle of the g-rid. Other groups from Washington State

University and New Mexico State University are also

working on perfecting operating parameters for this

device. While most of this work is aimed at detecting trace

environmental pollutants, the results are easily applicable

to explosives detection.

Further, quite recently, the Canadian firm Barringer has

claimed that its IMS machine can reliably detect plastic

explosives by adapting the device to collect and process

particles (as opposed to vapors). At least one set of

independent confirmatory tests has been made at Picatinny Arsenal, U.S. Army. The device has also been

tested in November 1990 by the FAA. Results have not
Appendix C—Vapor Detection Systems . 85

yet been publicly released. While this machine has been

demonstrated in the laboratory and for other purposes

(notably narcotics detection), field operability for explosives detection still needs to be determined.

Two Stage Mass Spectrometry (MS/MS—

Low Pressure Glow Discharge Ionization)

Sponsor:

Status:

Funding:

Department of Energy, work being done at Oak

Ridge National Laboratory (ORNL), Oak

Ridge, TN.

First generation system operational. Theoretical work on second generation device nearly

completed. ORNL wishes to transfer technology to industry for development.

Funded by the Department of Energy since

fiscal year 1984. Funding level was about

$400,000 in fiscal year 1990. About the same

amount or slightly less for each of the three

previous years.

Basic Operating Principles and Goals of Concept

Each mass spectrometry stage makes use of the fact that

many explosive molecules are nearly unique among

natural compounds in their electronegativity, that is, their

propensity to attract and capture an extra electron and

thereby become negative ions. Once ionized, they can be

accelerated and analyzed by subjecting them to electric

and/or magnetic fields. The mass-to-charge ratios of the

ions can be determined by any of a variety of means

referred to collectively as mass spectrometry.

In the MS/MS explosives sniffer developed at ORNL,

an air sample is drawn through a small orifice into a

low-pressure chamber where an electric current flows

through the sample and ionizes molecules of air and,

especially, of explosives, if present. This process is called

air sampling/glow discharge ionization (ASGDI). Due to

various inefficiencies and the contrary properties of

explosives molecules, the negative ions from the ASGDI

chamber that are injected into the first stage mass

spectrometer will include only 1 to 5 percent of the

explosives molecules originally drawn into the chamber.

By capturing the output of the first stage mass

spectrometer at a given time after injection or at a

predetermined spatial location, usually a slit, the ions with

particular mass-to-charge ratios are separated from the

complex mixture.

Large molecules, such as the explosive compounds,

can be fragmented into predictable smaller pieces. The

output of the first stage is brought into collision with a

stream of neutral atoms such as helium. The impacts cause

the large molecules to dissociate into smaller ions, the

masses of which can be determined by a second mass

spectrometer. Because it is unlikely that more than one

kind of molecule will both ionize to the proper mass-tocharge ratio and break down into the proper fragments,

this technique is considered to be very specific in

detecting explosive materials and thus yields a very low

false alarm rate.

Technical Description

An air sample is preconcentrated and drawn into the

analysis device. optimization of these preliminary steps

has not been a focus of the researchers at ORNL.

Molecules in the sample are ionized at low pressure

(approximately 0.8 torr) in a novel glow discharge

chamber. 5 By operating at low pressure and in short time

frames, they were able to avoid ion/molecule reactions

involving analyte ions that could cause the analyte ions to

transfer charges to background molecules, thereby eliminating or altering the signal.

The ions thus generated are then passed through a

quadruple mass filter: four parallel cylindrical rods that

create an electrical field pattern that effectively screens

out all ions except those of particular predetermined

mass-to-charge ratio. The mass-selected ions are then

broken into fragments by collision with helium gas. The

masses of the ionic fragments are then determined using

a time-of-flight spectrometer. In time-of-flight spectrometers, the ions are accelerated by applied electric fields and

sent through a flight tube. Ions of different masses pass

through the flight tube at different speeds.

In a second-generation device, both quadruple mass

filters and the time-of-flight instrument have been replaced with an ion-trap mass spectrometer (ITMS).6 This

change promises to provide a smaller, more specific, and

sturdier mass analyzer. The researchers at ORNL are

currently working on perfecting techniques for injecting

ions into the ITMS.

Potential and Shortcomings

This device was evaluated by Sandia National Laboratories in August 1988.7 It was found to be very insensitive

to interferants, even those suspected of being able to

disturb the glow discharge chemistry on which the

ionization of the first stage depends. The device was able

to respond accurately to samples of RDX, C-4, military

TNT, tetryl, the cut end of a sample of Primacord, and

Detasheet, although it should be noted that the test

SSe U.S. patent No. 4,849,628 issued July 18, 1989.

tjsMuA. McLuckey, Gary L. Gli@ and Keiji G. As~ot “Coupling of an Atmospheric-Sampling Ion Source with an Ion-Trap Mass Speetrometer,”

Analytica Chimica Acta 225 (1989) 25-35.

7F.J. Comd ~ndD.w. mu, “Ev~uation of tie oak~dge MS/MS &plosives Det~tor,” pp. 35-1 to 35-17, San&aNational bd30ratOrieS, 1988.
84 ● Technology Against Terrorism: The Federal Effort

protocol involved near contact with the explosive sample.8 Under these conditions, the device was sensitive to

concentrations of explosive molecules in the range of 0.3

to 30 parts per trillion and to quantities on the order of

50-100 femtograms. No problems with maintenance or

reliability were reported after the ion source had run for

months at a time without breakdown or need for cleaning.

Prototype versions of this arrangement have been used at

ORNL. Licensing agreements have been reached with a

private corporation that has plans to market a similar

device as an environmental monitor and is evaluating the

market for explosives detection.

Fluoroimmunoassay (Antigen-Antibody

Reactions as a Test Technique)

Sponsor:

Status:

Funding:

FAA Technical Center; work performed at

Naval Research Laboratory (NRL)

Beyond Proof-of-Principle. Awaiting practical

testing later this year.

$250,000 per year.

Basic Operating Principles and Goals of Concept

A continuous flow of vapor to be tested is drawn into

a preconcentrator at a rate of about 2,000 liters per minute

and collected in 1 ml of aqueous solvent. The output of the

preconcentrator is directed into the detection unit. This

unit is a small (200 microliter) vial containing immobilized antibodies and fluorescently labeled analogs of

explosive molecules. The antibody reacts with extreme

specificity to only one particular explosive. If present in

the sample, the explosive antigen will displace its

fluorescently labeled analog, which can be easily detected

downstream.

Technical Description

The test takes about 1 minute. To minimize false

alarms, two columns can be used in parallel, with the

second column containing an irrelevant antibody/

fluorphore-labeled molecule pair. Any substance that

causes an alarm from both columns is obviously not

reacting with the antibody but is releasing fluorescent

material by another pathway. Antibodies to more than one

explosive can be used simultaneously.

Other workers in this field (Westinghouse and Biometrics, Inc.) are also using antibodies to test for the presence

of explosives but use a capacitive device instead of

fluorescent labeling for detection.

Potential and Shortcomings

Field tests are scheduled to be conducted in the near

future. However, some performance characteristics can be

inferred from antibody detector work in other areas. The

detector is fairly inexpensive, fast, and fully automated.

Because each antibody is specific to a single compound,

a detection unit would need to contain antibodies to all

materials expected to be encountered. Researchers at NRL

claim that their device is sensitive to nanogram (10-9 g)

quantities of material. This is substantially less sensitive

than many other of the technologies discussed above.

However, the investigators are now working on coupling

a preconcentrator onto the front end of their device. This

technique is said to be able to convert a vapor sample

containing 10 ppt TNT into a 5 microliter solution, which

is easily detected by their machine.

SK the device failed to alarm under these conditions, a preconcentrator (such as a wad of quartz wool held near the explosive sample over w~ch an

air stream was drawn) was employed.

%nn.igan-Mat Corp., San Jose, CA.
Appendix D

Chemical and Biological Warfare Agent Detection

This appendix summarizes work done in detection of

chemical and biological agents in recent fiscal years.

Sponsor:

Status:

Funding:

Biochemical Detector System

U.S. Army-Chemical Research, Development, and Engineering Center (CRDEC).

Exploratory development of an automated

Army field device.

Approximately $5 million per year.

Basic Operating Principles and

Goals of Concept

This system is a “simple” point detection alarm that

classifies and partly quantifies nerve and blister gases as

well as pathogens and toxin agents. Detection is accomplished at levels consistent with human sensitivity to the

agents. The device is to operate unattended and continuously. The system consists of an aerosol sampling

subsystem, a sample preprocessor, and a detector.

Technical Description

This device is designed to be a 10-pound, l-cubic-foot

object that operates continuously when unattended.

A cassette feeds film through the sample stream drawn in

by the aerosol sampling subsystem (a suction pump). In

the preprocessor, antibodies from a storage system are

directed towards the sample where they attach to any

antigens that are present. The agglomerate sticks to the

film at specific locations. The antibody has an attached

radical that increases the acidity of a solution in which it

is dissolved. If the antibody/antigen combination is

present, the pH of the spot will then drop, due to the

increased acidity, indicating the presence of the agent.

The pH is measured indirectly through a simple measurement of the conductivity of the spot.

Status

This is a major Army development program designed

to bring chemical and biological weapon (CBW) detection capability to field use, and is not directly aimed at the

terrorist threat. The program is currently in exploratory

development. The engineering development phase is

slated to start in fiscal year 1993. Technology from this

program could be utilized to produce some near-term,

terrorist-specific hardware, which would not necessarily

have the same degree of automation or the same weight

specifications but might have the need for a more rapid

response.

Potential and Shortcomings

This point detector is a local measuring device with a

limited range. It responds only to those specific agents

that it is designed to search for. This is a general weakness

of all detection and analysis schemes that utilize anitbodies. Such systems are primarily useful when an attack by

a specific set of agents is suspected.

Chemical and Biological Mass Spectrometer

Sponsor:

Status:

Funding:

U.S. Army-CRDEC

Exploratory development—technology base

studies.

$8.8 million through fiscal year 1990-$30

million projected through to production and

deployment.

Basic Operating Principles and Goals of Concept

This device is a somewhat more sophisticated automated point detection system designed to detect, identify,

and semiquantify chemical and biological materials in an

air sample. It is designed to detect known chemical

agents, toxins, and pathogens that are listed in an internal

library.

In later versions, it is hoped that the device will be able

to identify unknown agents based on stored characteristics and expert system software (i.e., software that allows

the system to employ programmed methodologies, assembled from human pathologists, that are intended to

evaluate an unknown threat).

Technical Description

This instrument is a major extension of an existing

German mass spectrometer instrument, which can perform a limited detection and identification function. The

specified improvements over the existing device include

a quicker response time, a broader range of observable

materials, increased resolution (i.e., ability to identify), a

larger library of agents in the data bank, and reduced

physical weight, size, and power requirements. This

system is designed around a two-stage mass spectrometer

for detection and identification. It consists of a biosampler unit, an infrared pyrolyzer that prepares the

sample, and the mass spectrometer itself. The device is

designed to weigh 40 pounds and have a volume of

2 cubic feet.

Status

This is a long-range development program for the

Army, currently in the exploratory development phase. A

–87–
88 ● Technology Against Terrorism: The Federal Effort

simpler and more modest version of this technology,

possibly based on the German system, could be of some

value to the terrorist detection problem and could be

available at a much earlier date than the current Army

program.

Potential and Shortcomings

Like other chemical and biological detection and

identification concepts, this system depends on stored

data on potentially harmful agents that are known to exist.

The use of artificial intelligence techniques for implementing the process of identifying unknowns is in an

early stage of research and its success cannot yet be

forecast.

* * *

The following are smaller projects, sponsored by the

Technical Support Working Group (TSWG) and conducted by various laboratories and contractors under the

technical and contractual supervision of the Naval Explosive Ordnance Disposal Technology Center at Indian

Head, MD. In general, these programs do not develop

brand new technology, but are applications of existing

capabilities specifically to the counterterrorist problem.

Building Air Monitor

Sponsor: TSWG—through the U.S. Army CRDEC

Status: Contractor efforts at Los Alamos National

Laboratory (LANL) and at the Illinois Institute

of Technology Research Institute (IITRI) during fiscal years 1988, 1989, and 1990. Systems

demonstrated at CRDEC in 1989 and 1990.

Funding: LANL—$120,000 in fiscal year 1988;

$198,000 in fiscal year 1989.

IITRI--$351,000 in fiscal year 1988.

Basic Operating Principles, Goals of Concept,

and Technical Description

The object of both these efforts is to develop a real-time

chemical vapor and biological detection system to monitor fixed-site air supply systems. The LANL system

utilizes a Zeeman interferometer that detects the change

in the index of refraction of air or water when a

contaminant is present. The measurement is not very

sensitive or very specific, but is instantaneous. This is a

major advantage for an early warning system. The IITRI

program uses modified, off-the-shelf, flame photometry

equipment.

In the LANL system a commercial Zeeman laser1

shines through a reference chamber and into a photodetector. A phase shift between the two lines is measured and

related to the refractive index of the medium. For a

5-centimeter path length, the refractive index can be

measured to 1 part in 109

. In practical terms, the

sensitivity is about 1 part per million (ppm or 106) for air

and gases and about 1 part per billion (ppb or l09) in water

(the change in index is much greater for water). Since the

only observable is the change in index of refraction, the

device can only note that the baseline content of the air or

water has changed. The project has been completed and

a final report is nearly complete. No hardware has been

delivered.

The IITRI system uses a liquid chromatography and a

standard flame photometer to identify GB, VX, and DFP

(nerve gases) concentrations at parts per trillion (ppt or

1012) levels in a 7-minute analysis cycle. In a flame

photometer, the sample is passed through a flame that

excites the molecules present. These excited molecules

then radiate light at characteristic frequencies, which can

be used to identify the molecular species. The work on

this project was initiated in fiscal year 1989 and is

continuing through 1990. Demonstration of the capabilities of the system is expected at CRDEC in the near future.

Real-Time Water Monitor

Sponsor: TSWG—through CRDEC program.

Status; Program scheduled for completion soon. Project is being carried out with the support of the

Environmental Protection Agency (EPA) by a

contractor.

Funding: $510,000 in fiscal year 1988; $486,000 in

fiscal year 1989.

Basic Operating Principles, Goals of Concept,

and Technical Description

The object of this program is to develop a highly

sensitive and specific monitoring device capable of

measuring chemical and biological contaminants in

surface and ground water supplies.

The system consists of a sampler and preconditioned

module, which gathers a sample from the water supply

piping. The sample is heated uniformly to a set temperature and its pH adjusted to a set level. The sample is then

processed to remove excess minerals. The conditioned

sample is then fed to two sample modules, one to detect

chemical contaminants and one to detect pathogens.

Currently this system is partially developed and tested,

with the pathogen unit lagging behind schedule. Operating and detection software are also being written and

tested, with the pathogen system again behind the other.

z~t is, tie fiwuen~ canbe s~ted rapidly among many different lines that arise from transitions between energy levels of a multitude of rotatioti

and vibrational states of the COZ molecule.
Appendix D-Chemical and Biological Warfare Agent Detection ● 89

Combination Detector System

Sponsor: TSWG—through CRDEC program.

Status: Demonstration of feasibility soon.

Funding: $521,000 in fiscal year 1988; $270,000 in

fiscal year 1989.

Basic Operating Principles, Goals of Concept,

and Technical Description

The objective of this program is to develop an on-line

air and water monitoring system for chemical (nerve) and

biological agents using a laser fluorometer to detect

changes in the fluorescence of a sample. The work is

being undertaken at LANL. The system can detect one ppt

of nerve agent and 0.1 ppt of biological protein in

aerosols, with a sensitivity of about a factor of 100 lower

in water. Detection times are quick.

A sampler collects either a gaseous or a liquid sample

into a continuous flow system. A pulsed laser (KrF

excimer laser) fluoroscope irradiates the sample. To

detect nerve agents, immobilized acetylcholinesterase

(the actual target of nerve agents) is exposed to the sample

and is then monitored using a substrate that fluoresces

under illumination by the ultraviolet (UV) laser light.

A change in activity indicates the presence of a nerve

agent. To detect bacterial particles, the system observes

the fluorescence emitted by aromatic amino acids and

proteins (usually tryptophan) when excited by the uv

light. The fluorescence-based chemistry for these compounds has been developed under this program.

This system is nonspecific and is intended as a “first

alarm.” The hardware consists of state-of-the-art laser

and other components and weighs on the order of 45

kilograms.

Sponsor:

Status:

Funding:

Remote Agent Detector

TSWG—through CRDEC.

Feasibility demonstrated in fiscal year 1990.

At Stanford Research Institute (SRI)—

$428,000 in fiscal year 1988; $0 in fiscal year

1989; $405,000 in fiscal year 1990. CRDEC

contributed $50,000 in fiscal year 1989.

At LANL--$497,000 in fiscal year 1988;

$450,000 in fiscal year 1989.

Basic Operating Principles, Goals of Concept,

and Technical Description

Two concepts, based on different operating principles,

are being pursued by two contractors (one at SRI and one

at LANL). Both are lidar systems, i.e. radar-like systems

using pulses of light instead of microwaves. Each operates

by sending out a pulse of light and measuring the

backscattered energy and time of arrival. The intensity

gives some indication of the strength of the scatterer, i.e.,

its concentration, and the time of arrival gives the range

to the backscatterer, i.e., its location. Consequently, lidar

systems can map the location and concentration of a cloud

containing an agent.

The SRI system uses a frequency agile,2 pulsed,

infrared (CO2) laser operated in a differential absorption

mode (DIAL). In a lidar system some light must be

reflected back to the detection telescope; the source of the

reflection can be a topographical object (the ground, trees,

any reflector behind the cloud to be observed), or it can be

the aerosol particles of the cloud itself. In either case two

(at least) pulses of different wavelengths are emitted in

rapid succession, one at a wavelength where the agent in

the cloud absorbs and one at very nearly the same

wavelength but where the agent does not absorb. The

differences between the two signals can be used to

determine the concentration and in some cases the

location of the agent cloud.

Laser DIAL techniques for atmospheric measurements

have advanced to a fairly high state of technology, using

both air- and land-based mobile platforms. The SRI

program is an application of the state of the art to CBW

detection. The U.S. Army has an aggressive research

program aimed at developing mobile (moving) detection

capability with ranges out to 10 kilometers (km), with

both aerosol and surface contaminant capability. The

system under development for TSWG is designed for a

range of only 1 km but permits automatic, unattended

operation. It is closely related to much larger Armysponsored efforts and employs very similar technology.

A system demonstration is scheduled soon.

The remote agent detection system being developed by

LANL is based on measuring fluorescence induced by the

absorption of ultraviolet (UV) photons from a pulsed uv

(KrF excimer) laser. The uv light pulses excite fluorescent

radiation of amino acids in the protein of toxins or

bacterial spores or cells. The measurement is not specific.

A telescope detects the fluorescence and, utilizing appropriate computer software, the system determines the

location and pattern of the cloud and produces a map. At

present, the system has a demonstrated range of 1.2 km.

The system was field tested in October 1989 to demonstrate the feasibility of the concept.

Sponsor:

Status:

Mobile Laboratory

TSWG—through CRDEC program.

One of two modules complete in fiscal year

1989; the second to be completed in the near

future, funding permitting.
90 ● Technology Against Terrorism: The Federal Effort

Funding: $611,000 in fiscal year 1988; $0 in fiscal year

1989; $645,000 in fiscal year 1990.

Principles of Operation, Goals of Program, and

Technical Description

The objective of this program is to develop a fully

transportable, rapid response, analytic laboratory, capable

of sustained operation in a contaminated environment, to

detect, identify, and quantify the spread of chemical and

biological agents released by terrorists into the water or

air. The program is being conducted with support from the

Environmental Protection Agency (EPA) by a contractor,

Engineering Computer Optecnomics (ECO), Inc.

The significant characteristic of this concept is that the

lab is readily mobile, that is, it can be transported by

helicopter, aircraft, truck, rail, or ship. It is designed to

respond to an emergency call and be onsite and ready to

function within a few hours of a decision to deploy. The

laboratory is a fully self-sustained, closed ecological

system; containing its own water, electricity, fuel, and

waste disposal; protective gear for the operators; and

airlocks for entry and egress without contamination. It is

designed as a positive over-pressure air system with

intake air filtration. It has analytic capability for both

chemical and biological agents, including a gas chromatograph, a mass spectrometer, various chemical agent test

kits, immunologic test equipment, and sample culture

apparatus. It also contains a modified glove box with

sample pass-through arrangements and decontamination

capability.

The analytic laboratory (an 8 x 20 foot van module) has

been completed. A coupled unit containing living quarters

has been designed but not completed due to a lack of

funding in fiscal year 1989. It is scheduled for completion

soon.

Sponsor:

Status:

Funding:

General

Improved Expedient

TSWG--through CRDEC,

Prototypes available.

Hood

$122,000 in fiscal year 1989.

Principles of Operation

The objective of this program is to develop a low-cost,

disposable, limited-time-duration (5 to 15 minutes), ocular and respiratory protection system for key human

beings in case of an unexpected terrorist attack using

chemical or biological agents. The device is simply a

hood with an integral breathing apparatus (with an

activated charcoal filter) and an air seal at the neck, which

provides a temporary, lightweight, sealed environment

for the wearer.

This development is an upgrade of current chemical

agent protective gear to make it lighter, easier to store, and

cheaper to manufacture. Its chief advantage is that it is a

very small package that will enable potential targets, or

their guards, to carry it easily for rapid use. The program

will test various designs that have been fabricated in fiscal

year 1990 and select a final design for future acquisition.
Appendix E

Recent Federal Counterterrorism Research Efforts:

Agencies and Their Budgets

Summary

This appendix consists of a catalog of Federal agencies

currently exploring new technologies applicable to the

fight against terrorism. It begins with a review of the

budgets devoted to these efforts in some recent fiscal

years. A brief description of the direction each agency has

taken in research efforts is also provided.

The largest expenditure of research funds (almost $200

million per year) described is made by the Department of

Defense (DoD). The Army has budgeted about $165

million per year to support development of a wide array

of technologies, from protection against chemical and

biological assault, to explosives detection, to physical

security and site protection. Nearly all of this effort is

directed towards the support of battlefield objectives,

including the area of low-intensity conflict. But some

items may also be applicable to counterterrorism.

In the specific area of combating terrorism, the military

services have budgeted some $16 million in fiscal year

1990 for R&D. Further, the Defense Nuclear Agency

bears primary responsibility for protecting the Nation’s

nuclear weapons stockpile and has been working on

improving means to detect and deter intruders (about $5

million per year). Another DoD agency, the Defense

Advanced Research Projects Agency (DARPA), has just

begun to direct its attention to the threats posed by

terrorism and has budgeted about $5 million this year for

research into this field. Some other DoD components have

smaller efforts.

Most other Federal agencies spend much less than

DoD. The Federal Aviation Administration (FAA) runs

second to Defense in yearly expenditures (among the

agencies that gave OTA information). The FAA Technical Center in Atlantic City, NJ spent about $13 million in

fiscal year 1990 and is planning to spend about twice that

much in fiscal year 1991 to develop enhanced security

measures for commercial aviation. The Department of

State, whose overseas facilities have frequently been the

target of terrorist activities, is supporting research into a

variety of security measures including explosives detection, site hardening and intrusion detection, and countermeasures. Over the last 4 years, State has invested about

$7 million in this effort. State also leads the Technical

Support Working Group, a unique interagency effort to

recognize and support promising research and development in counterterrorist measures not adequately supported by any other agency.

In fiscal year 1989, the Department of Energy spent

about $6 million researching new technologies, primarily

in connection with their nuclear safeguards and security

programs. Within the Treasury Department, the U.S.

Customs Service has recently devoted about $5 million

per year to developing technologies applicable to counterterrorism, mostly focusing on one large project. The

United States Secret Service, another Treasury agency,

has a clear interest in developing defenses against

terrorism, but its research budget is quite modest (a few

hundred thousand dollars per year). It depends on

adapting the research of others to their needs.

Surprisingly, the Federal Bureau of Investigation,

which has been given primary responsibility for responding to most domestic terrorist incidents, has a very small

counterterrorism research budget. Its needs are closely

aligned with those of the Department of Defense, and it

makes liberal use of developments pioneered there.

A number of agencies have not been mentioned in

detail in this report. Access to some (in the intelligence

community) has not been obtained.

The Federal Research Effort Into

Counterterrorism Technologies

For several reasons it is difficult to categorize unambiguously given activities of the various Federal

agencies as directed specifically towards research into

counterterrorism. For many agencies it is difficult to

distinguish research performed for the main agency

mission from that performed specifically for counterterrorism because the two efforts are often closely

aligned. Also, some law enforcement activities, such as

drug interdiction, frequently involve work that parallels

counterterrorism research, but usually is distinct from it.

Moreover, the line between research and development on

the one hand and implementation on the other is not sharp;

one frequently blends imperceptibly into the other as

experience in the field is used to perfect an idea.

Table E-1 presents a partial list of agencies that have

performed at least some research and development

directly in, or at least applicable to, the field of counterterrorism.

The sections below discuss the activities of some of

these organizations and, where the information is available, the main lines of research and funding levels.

–91–
92 ● Technology Against Terrorism: The Federal Effort

Table E-l—Federal Agencies Engaged in

Counterterrorism Research

Agency

Department of Defense

Department of Energy

EG&G (laboratories at Las Vegas and Santa Barbara)

Los Alamos National Laboratory (LANL)

Sandia National Laboratories (SNL)

Oak Ridge National Laboratory (ORNL)

Idaho National Engineering Laboratory (INEL)

Department of Justice

Federal Bureau of Investigation (FBI)

Immigration and Naturalization Service (INS)

National Institute of Justice

Department of State

Office of the Ambassador for Counterterrorism

Bureau of Diplomatic Security

Department of Transportation

Federal Aviation Administration (FAA)

Transportation Systems Center (TSC)

Department of the Treasury

Bureau of Alcoholr Tobacco, and firearms (BATF)

U.S. Customs Service (USCS)

U.S. Secret Service (USSS)

Environmental Protection Agency (EPA)

Interagency Intelligence Committee on Terrorism--Community

Counterterrorism Board

SOURCE: Office of Technology Assessment, 1991.

National Counterterrorism Research and

Development Program

Early in the 1970s, it was recognized that some sort of

coordination would be necessary to establish clear lines of

responsibility and maintain adequate channels of communication among these players. To this end, various groups

and committees were established by every administration,

beginning with President Nixon’s. A consistent theme has

been the lead agency concept, whereby a particular

agency is given responsibility for responding to certain

types of incidents. The following current lead agency

assignments were developed during the Reagan Administrationl

:

Department of State-incidents that take place

outside U.S. territory,

Department of Justice (FBI)--incidents that take

place within U.S. territory, and

Federal Aviation Administration (FAA)--incidents

aboard aircraft in flight that take place within the

special jurisdiction of the United States.

In addition, the tasks of coordination and communication still needed to be assigned. One organization

charged with shouldering these duties is the Policy

Coordinating Committee on Terrorism (PCC/T), originally known as the Interagency Group on Terrorism (IGT)

when it was created in 1982. The committee has two

important functions: 1) to bring cohesion to the overall

U.S. Government counterterrorism effort and 2) to

coordinate the programs of the member agencies for

combating terrorism. chaired by the State Department’s

Coordinator for Counterterrorism, Ambassador Morris

Busby, committee members are drawn from about 25 U.S.

Government organizations. Within the committee, various working groups have been established, for example,

the Public Diplomacy Working Group, which is designed

to generate greater global understanding of the threat of

terrorism and the efforts to resist it; and the Maritime

Security Working Group, which assesses port and shipping vulnerabilities to terrorism.2

One of the most important subcommittees of the

PCC/T is the Technical Support Working Group

(TSWG), which administers the National Counterterrorism Research and Development Program. Through this

program, research into promising technologies is supported by “seed money” grants. The idea is that, after

prototyping, successful efforts will be picked up and

implemented by one or another Federal, State, or local

agency. The unique contribution of this group is that it is

specifically designed to support research into technologies that would otherwise go undeveloped, either because

other agencies do not find a sufficiently direct linkage to

their mission or because they are concentrating their

priorities on other projects.

The TSWG is cochaired by representatives of the

Departments of Energy and Defense. Its members are

drawn from an interagency group of scientists and

technical and terrorism specialists organized into seven

general areas: Threat Assessment and Database Management; Intrusion Detection and Countermeasures; Conventional Incident Response; Nuclear Incident Response;

Chemical and Biological Incident Response; Explosives

Disposal; and Technology Transfer. Some of the agencies

participating in the TSWG include the Food and Drug

Administration, the Environmental Protection Agency,

the Federal Aviation Administration, the Federal Bureau

of Investigation, the Department of Energy, the Department of the Army, the Department of the Navy, the

Department of the Air Force and the Defense Intelligence

Agency. Contacts with other nations have also been made.

A list of candidate technologies to be considered for

inclusion in the program is developed periodically. After

interagency discussion among the TSWG members,

candidate projects are ranked based on priority and

feasibility, and the ranked list is then submitted to the

PCC/T Chairman for approval. Funds for the projects

l~bfic Report of tie Vice President’s Task Force on Combatting Terrorism, February 1986, P. 8.

21bid., p. 34.
Appendix E--Recent Federal Counterterrorism Research Efforts: Agencies and Their Budgets ● 93

come out of the budget of the State Department, but

contracting and administrative support is provided at

nominal expense (a few hundred thousand dollars per

year) by the Department of Defense. One or more TSWG

members supervise each project, with the research work

actually being conducted either at the facilities of the

member agencies or through subcontracting with various

other laboratories and organizations both within and

outside the Federal Government. Some of these are:

Bendix Corp., Motorola Corp., the Illinois Institute of

Technology, Los Alamos National Laboratory, the Naval

Research Laboratory, and the Air Force Electronics

System Division.

Funding for this effort was frost authorized by Congress

in 1986 (Public Law 99-349). The appropriation is not a

line item, but is-deeply embedded in the State Department’s diplomatic security salaries and expenses account.

The consequences of such fiscal anonymity are reflected

in the consistently declining budget of the PCC/T. In its

first year, 1986, riding a wave of public outrage over

terrorist atrocities in the Middle East, the program was

granted a budget of $10 million. These funds were part of

a late supplemental appropriation and carried the program

through fiscal year 1987. In fiscal year 1988, enthusiasm

was beginning to wane. Of the $9 million requested, $7

million was appropriated. The next year, fiscal year 1989,

as other priorities strained the national budget, the

program became embroiled in battle over where, bureaucratically, such a research effort should be centered. Six

million dollars were requested but only half that amount

was approved, a compromise between the full funding

appropriated by the House of Representatives and zero

funding ordered by the Senate. Funding levels for fiscal

year 1990 headed downward again, this time to the $2

million level. In fiscal year 1991, Congress agreed on an

increase to $3 million, but internal funding reductions at

the State Department made necessary by the budget

agreement between Congress and the executive branch in

late 1990 brought the actual number back to $2 million.

These cuts have resulted in termination or suspension

of a number of projects because funding could not be

assured. In an effort to keep the maxi-mum number of

programs alive, a “good faith” or “matching funds”

concept was implemented by TSWG, in which agencies

participating in a research project were required to find

funds to make up the difference between the amount

allotted and the amount needed to run the project.

Typically, the other agency had not planned on any

expenditure of this nature and the last minute budget

scramble was not always easy or successful. Such

stop-and-go financing, while intended as a cost containment measure, is actually frequently counterproductive: it

winds up killing some projects and adding to the ultimate

price of others.3

Another handicap of a restricted budget is the absence

of funds available even for the purpose of properly

documenting the research that is conducted. Essentially

all available dollars go into the research itself and there is

little or no money left over to spend on disseminating the

results. While a shoestring operation can sometimes

produce useful work, more often than not the shoestring

breaks before it can accomplish its mission.

The PCC/T staff asserts that an assured annual budget

of at least $6 million would permit far more efficient

operation.

PCC/T-TSWG Projects

In its short lifetime, the National Counterterrorism

Research and Development Program has not had time or

resources to complete many activities. Still, more than 50

projects have been proposed. Of these, almost 30 have

been initiated and about 14 are at or near completion. A

quick overview of several of these projects will show the

breadth of the TSWG effort. Most items are reviewed in

more detail in appendixes A through D.

The Transportable Emergency Response

Monitoring Module

This project received $611,000 in fiscal year 1988 and

$645,000 in fiscal year 1990. This unique, rapid response,

transportable laboratory is designed for sustained operations in areas suspected of being contaminated by

chemical or biological warfare agents. Instruments aboard

the laboratory can detect, identify, quantify, and predict

the spread of chemical and biological agents released by

terrorists into water supplies and air. An interdisciplinary

effort, the unit was designed and built by Engineering

Computer Optecnomics, Inc. of Annapolis, MD using

TSWG funds. The project manager came from the

Environmental Protection Agency, and technical assistance was provided the U.S. Army’s Chemical Research,

Development, and Engineering Center (CRDEC). The

unit will ultimately consist of two modules. Each unit will

be about the size and shape of a semitrailer and is adapted

for deployment by truck, helicopter, aircraft, railroad,

ship, or barge. The analytical laboratory module, which

has been constructed and can operate on its own, contains

numerous pieces of modern laboratory equipment, all

hardened to survive a not-too-gentle deployment. Air

locks and decontamination showers are also provided.

The living quarters module, construction of which has

been delayed by lack of funds, will be attachable to the

3sm, U.S. CongeSS, OWlce of Technology Assessmen4 “Introduction and Mcipal Fin@s,” The Defense Technology Base: Introduction and

Overviti Special Report, OTA-ISC-374 (Washington, DC: U.S. Government Printing ~lce, March 1988), for a farther discussion of the problems

associated with fluctuating research funding levels.
94 ● Technology Against Terrorism: The Federal Effort

laboratory module and will provide completely selfcontained operations for up to 7 days. This laboratory is

uniquely capable of an on-the-spot response to a suspected chemical or biological attack. This effort has been

successful despite a 1 year suspension in fiscal year 1989

due to lack of funds.

Expedient Hood

Also under the technical direction of CRDEC, this

project resulted in the development of a prototype of an

inexpensive, compact protective hood that could provide

the wearer with 10 to 30 minutes of emergency ocular and

respiratory protection against chemical or biological

agents. The hood is now ready for further refinement by

suitable agencies. The TSWG invested about $122,000 of

its fiscal year 1989 funds in this project.

The Radiofrequency (RF) Quadruple

Generator

The objective of this project was the development of a

small, compact electronic neutron generating source for

use in explosives detectors employed by airports. The unit

was developed by ACCSYS Technology, located in

Pleasanton, CA, and is designed to replace the radioactive

neutron source currently used by explosives detectors

based on thermal neutron analysis (see ch. 4 and app. A).

A successful prototype has been produced. In fiscal year

1988 and fiscal year 1989 respectively, $248,000 and

$125,000 of TSWG funds were allocated to this project.

Chemical Taggant for Plastic Explosives

In the spring of 1989, following the destruction of Pan

Am Flight 103, two international groups held meetings to

discuss what could be done to make small bombs carried

aboard commercial aircraft easier to detect. Both groups

determined that research should be conducted into

suitable chemical taggants for the plastic explosives that

constituted the main terrorist threat. Without the TSWG,

there probably would not have been any U.S. contribution

to this effort. On a minuscule budget of $35,000 supplied

by the TSWG, a chemist from the Army’s Armament

Development Command at Picatinny Arsenal, NJ, was

able to test the various proposed compounds and supply

the United States representatives to these organizations

with what would prove to be their only technical support.4

Remote Detection Instrument

The objective of this effort is to develop an early

warning system capable of detecting and identifying

chemical agents at least 1 kilometer away using an

infrared laser. In fiscal year 1988, this project received

$428,000 from the TSWG and $405,000 in fiscal year

1990. The U.S. Army Chemical Research, Development

and Engineering Center in Maryland is working with the

SRI Corp. of California in the development of this

instrument.

This incomplete list gives at least a flavor for the depth

and breadth of efforts that the TSWG has supported or

sponsored.

Other Agencies

This section contains descriptions of some of the work

performed by other agencies, including efforts to deter or

prevent terrorist acts as well as preparations for coping

with a terrorist incident once it develops.

Department of Defense

Agencies Within Department of Defense

Relevant budget: fiscal year 1990-about $11 million

Several agencies are working on terrorism-related

projects, covering fields such as explosives detection,

threat prediction, and physical security. The latter field

represents a major part of this group of efforts.

DoD has a budget of about $40 million per year devoted

to physical security. Of this, about $5 million is allocated

for exploratory development. Most of these projects

involve development of novel means to detect and/or

disable intruders. For example, one project includes a van

or truck equipped with a combination of two infrared

detectors capable of finding and tracking an intruder at a

significant distance. Other detection strategies involve the

use of various combinations of seismic, acoustic, infrared,

and electrical sensors. Less esoteric undertakings are

directed at improving physical barriers such as fences.

Some agencies within DoD have been cooperating on

joint ventures with other DoD agencies and with each

other. For example, one agency has worked with the

Department of State on strategies for hardening our

embassies and other facilities overseas and two DoD

agencies have worked on the development of an early

warning threat detection system, having shared startup

funds for this project.

Several programs under the aegis of these agencies

within DoD have been transferred to the U.S. Navy. These

include the acoustic lens sonar and the multifunctional

sensor programs. Other Navy-specific programs include

a Swimmer Identification System, which will provide an

autonomous alarm system for detection of surface and

subsurface swimmers; Waterside Lightweight Barriers,

which will provide protection against high-speed, explosive laden boats; an Underwater Security Vehicle for

positive identification of underwater intruders, and several other programs designed to meet the Navy’s operaAHOWeVer, from fiscal year 1989 through fiscal year 1991, a cumulative total of $285,000 was provided by TSWG to the Armament Development

Commaud for a tagging plastic explosives project.
Appendix E--Recent Federal Counterterrorism Research Efforts: Agencies and Their Budgets . 95

tional requirements for Waterside and Shipboard Security

Systems.

Military Services

Relevant budget: for fiscal year 1990,$16 million

directly for counterterrorist activities

For fiscal year 1990, the Army allocated about $167

million to research activities that might be characterized

as pertaining to the fight against terrorism. For fiscal year

1991, the Army expects to invest about an equivalent

amount. This research includes literally dozens of projects

aimed at developing materiel, munitions, equipment, and

procedures for supporting special operations and dealing

with low-intensity conflict. Many of these efforts are

suitable in a counterterrorist context as well, although few

are specifically designated as such.

The following groups contribute to Army R&D applicable to counterterrorism, roughly ranked by size of their

effort:

●

●

●

●

●

●

●

●

●

●

Chemical Research, Development, and Engineering

Center;

U.S. Army Medical Research Institute of Infectious

Diseases;

U.S. Army Medical Research Institute of Chemical

Defense;

Aviation Systems Command;

Natick Research, Development, and Engineering

Center;

Communications-Electronics Command;

Belvoir Research, Development, and Engineering

Center;

Army Research Office;

Corps of Engineers; and

Atmospheric Sciences Laboratory.

The Army is a member of the PCC/T (described above)

and its Technical Support Working Group particularly in

the areas of Threat Assessment, Intrusion Detection

Countermeasures, and Chem/Bio Incident Response

R&D. It also is involved with other interagency efforts.

The main line of investigation (about 85 percent of the

research budget) is directed at defense against chemical or

biological weapons, reflecting the Army’s role as the DoD

executive agent for chemical and biological defense

research. This work can be broken down into four

categories:

1. reconnaissance, detection, and identification;

2. protection;

3. decontamination; and

4. medical diagnosis and casualty care.

For example, at the Army Atmospheric Sciences Laboratory, research is being done into using computer modeling

to predict the spread and dispersion of an aerosol agent.

Also, work is being done to develop light weight

overgarments that troops could wear to protect against

toxic or biological threats. Further, a system for remotely

monitoring the vital signs of a soldier is being developed.

This would allow quick medical decisions to be made,

even in a contaminated environment. Other lines of

research include intrusion detection, physical security,

explosives detection, and incident response.

While most of this activity is related to counterterrorism only as an off-shoot of the direct research mission,

at least one Army program is specifically targeted towards

research into counterterrorism technologies. Within the

Chemical Research, Development, and Engineering Center lies the Chemical/Biological Antiterrorism program.

This small unit (fiscal year 1989 budget = $99,000 of

Army funds, $6.2 million customer (that is to say,

non-Army) funds), is charged with development of

protective gear, decontamination equipment, detection/

identification equipment and less-than-lethal techniques

specifically to cope with terrorist incidents. This group

also provides technical support for other government

agencies in the field of countering the threat of chemical/

biological terrorism. In particular, the TSWG, the U.S.

Secret Service, the National Institute of Justice, the

Federal Bureau of Investigation, and other DoD agencies

make use of the counter/antiterrorism5 expertise of this

group.

In addition, the Army has allocated some $10 million

in fiscal year 1990 for R&D specifically aimed at

developing technology for combatting terrorism in special operations contexts. Other services together have

allocated an additional $6 million to this end.

Department of Energy

Relevant budget: $6 million for fiscal year 1989

Through its Special Technologies Program, the Department of Energy (DoE) is doing a considerable amount of

work in areas useful to the fight against terrorism. Much

of this effort, handled at DoE’s Laboratories in Las Vegas

and Santa Barbara, CA, is related to DoE’s responsibilities under the Atomic Energy Act. A large, separate but

related, budget is devoted to development and support of

the Nuclear Emergency Support Teams (NEST), whose

mission is to find and recover purloined nuclear material

and provide technical support to other government

agencies in responding to radiological threats. Additional

funds are spent by the safeguards and security program,

primarily in antiterrorism. There is a substantial amount

of work in the area of remote detection of nuclear material

s“~titemonsm” is tie term used by the military to refer to passive defenses against terrofism. “Countertermrism” refers to active responses to

terrorist attacks. This report employs the latter term for both purposes, since it is generally understood as such by the public.
96 ● Technology Against Terrorism: The Federal Effort

and nuclear weapons. In addition, a significant effort

exists, in collaboration with the Naval Explosive Ordnance Disposal Technology Center, in developing means

of detecting and countering alarm systems, especially

those based on infrared or microwave, and acoustic

technologies. However, several laboratories are involved

in development of other counterterrorist techniques, many

funded not out of the $6 million referred to above, but out

of laboratory funds for other programs, or out of

reimbursable contracts from other Federal agencies.

Los Alamos National Laboratory (LANL)

A substantial amount of work related to counterterrorism is performed at LANL. One area of work is in

diagnostics and disablement, which includes research

aimed at bolstering defenses against nuclear terrorism.

Another set of efforts is in a program of R&D in low

intensity conflict, special operations, counterterrorism,

and counternarcotics. This program spent about $19

million in fiscal year 1989, of which perhaps $9 million

was devoted to counterterrorism. Most of the funding is

in reimbursable projects from other government agencies

and some is from the TSWG. Some typical fields of

research include methods of early detection of chemical

and biological agents, miniaturized radar for remote

emplacement, and development of computer techniques

for analyzing large quantities of real-time financial data to

detect money laundering. Other divisions of LANL are

involved in advanced technologies for explosives detection and laser means for remote detection of biological

agents.

Sandia National Laboratories (SNL)

SNL is the lead laboratory within DoE for R&D into

physical security, and as such is active in the development

and evaluation of numerous devices applicable to counterterrorism. In particular, it conducts tests and evaluations of explosives detectors, intrusion detectors, and

metal detectors. It has explored various schemes for

access control, especially rapid identity verification,

including voice print, hand profile, retina scan, finger

prints, and signature dynamics. Research has also been

carried out on barriers to intrusion such as smoke and

foams.

In addition, for many years, SNL has had a program of

evaluation and development in both explosives detection

and weapons detection. There has been a significant

transfer of experience and technology to the private sector

in these areas.

Sandia Laboratories is being funded by the FAA’s

Technical Center to develop a systems approach to airport

security, the “Enhanced Security Demonstration Project’ for BWI airport near Baltimore, MD, discussed in

chapter 4. Low intensity conflict has been another area of

research for Sandia that is of interest to counterterrorism.

In this field, it is investigating remote sensors, portable

satellite communication, and alarm and annunciator

systems for noncombatants in a danger area.

Sandia has also been working with the FBI, Customs

and the INS especially in the field of counter narcotics,

having been designated a ‘‘center of excellence” for this

purpose under Public Law 100-790. This work especially

involves development of such items as night vision

equipment and motion sensors.

Oak Ridge National Laboratory

About $400,000 per year for the last 3 years has been

invested by DoE at its Oak Ridge National Laboratory in

Oak Ridge, TN for the development of a mass spectrometer capable of detecting and identifying tiny amounts of

vapor emitted by plastic explosives. Additional fiscal year

1990 funds have been utilized to seed technologies that

have counterterrorism applications.

Idaho National Engineering Laboratory

About $400,000 per year has also been invested by

DoE at its Idaho National Engineering Laboratory

(INEL). Additional fiscal year 1990 funds have also been

utilized here to seed technologies which have counterterrorism applications.

Department of Justice

Federal Bureau of Investigation

Relevant budget: small-exact figure not available at

this time

The FBI’s Hostage Rescue Team has responsibility for

events, including terrorist incidents, that involve Federal

or interstate jurisdiction. They do very little R&D, being

mostly an operational unit. However, they have channeled

some DoD funds (approximately $1 to $2 million per

year) to outside contractors for relevant research.

The Special Operations Research Unit is working on

less-than-lethal weapons and incapacitating agents; some

of this work is sponsored by the National Institute of

Justice. The Forensic Science Center performs work on

evaluation of explosives detectors. In particular, in March

of 1988, the Center performed a meticulous series of

“real-world’ tests on a group of explosives vapors

detectors representative of then commercially available

models.6 The total research budget of this center is

$300,000 for fiscal year 1990, half of that available in

earlier years. Only part of this budget is devoted

specifically to counterterrorist activity. The FBI also

15SCC Explosives lleteCrOrEVul~fi”On, a limited distribution report produced by the FBI Laboratory, Forensic Science Research and Trtig Centm,

FBI Academy, Quantico, VA 22135, Ma. 21-24, 1988. Registered copies for official use are available by writing to the above address on letterhead.
Appendix E--Recent Federal Counterterrorism Research Efforts: Agencies and Their Budgets ● 97

supports the explosives detection community in two other

ways. Every October, they sponsor and organize a

symposium to discuss current R&D efforts. Also, the FBI

Laboratory analyzes all samples of foreign explosives

gathered by other law enforcement agencies.

Immigration and Naturalization Service (INS)

Relevant budget: $400,000 for fiscal year 1990

This service has ongoing R&D efforts in the area of

facial recognition and technologies related to document

verification. The Service’s Forensic Laboratory has no

funds available for research and development.

National Institute of Justice

Relevant budget: $500,000 for fiscal year 1989 (to

CRDEC)

This money funded work on less-than-lethal agents.

Similar work was channeled through the FBI to other

contractors.

Department of State

Office of the Ambassador for Counterterrorism (Technical Support Working Group)

Relevant budget: fiscal year 1986-87--$10 million

fiscal year 1988--$7 million

fiscal year 1989--$3 million

fiscal year 1990--$2 million

See chapters 1 and 4 and above sections

appendix for more information on this project.

Bureau of Diplomatic Security

in this

Relevant budget: fiscal years 1986-9=6.5 million for

explosives detection; the current

budget includes $300,000 to

$400,000 per year on other research.

This office is responsible for assuring the security of

State Department property and personnel. The largest part

of its research budget has been expended in supporting the

development of an explosives “sniffer.” See appendix C

of this report for information on the Thermedics, Inc.

explosive detector. A much smaller budget is devoted to

research into alarms, locks, closed-circuit TV, blast hardening of buildings, and technical countermeasures to mask

radio signals. Finally, some work is being conducted in

cooperation with the intelligence community.

Department of Transportation

Federal Aviation Administration

Relevant budget: see table E-2

The FAA Technical Center, located in Atlantic City,

NJ, manages a wide range of research programs aimed at

developing systems and devices to prevent aviation

related hijacking and sabotage. These include efforts

aimed at explosives detection, airport security, and

security systems integration. Perhaps its best known field

of investigation is the thermal neutron analysis (TNA)

technique of explosives detection, discussed in detail in

chapter 4 and appendix A. It has also heavily funded the

development of the chemiluminescent-based explosives

vapor detection equipment especially as a portal monitor

for concourse security. Other technical approaches to

explosives detection currently under investigation are:

●

●

vapor approaches (which seek to detect molecules of

explosives in the air or on external surfaces):

—Advanced Ion Mobility

-Surface Acoustic Wave

—Modulated Infrared Absorption

—Preconcentration

bulk approaches (which use various types of

penetrating radiation to interact with an explosive

hidden inside a package, producing detectable secondary radiation):

—Nuclear Resonance Absorption

—Fast Neutron Scattering

—Nuclear Magnetic Resonance

—Expert Systems (not a detection technique in

itself, but the use of computer software in support

of bulk approaches)

The agency is working to expand this list. In an effort

to attract numerous new strategies and approaches for

explosives detection, the FAA has recently issued a Broad

Agency Announcement. They are also sponsoring or

attending numerous seminars and interagency and international symposia to improve research efforts in this area.

A large part of the FAA’s research budget for the next

several years ($3 million for fiscal year 1990) will be

devoted to the BWI Airport Demonstration project. This

project has enlisted the technical expertise of DoE’s

Sandia National Laboratories to assist in the development

of a complete systems approach to airport security

including access control as well as explosives and

weapons detection.

Funding for major programs for fiscal year 1990 are

listed in table E-3.

Department of the Treasury

Bureau of Alcohol, Tobacco, and Firearms

This agency has some research activity of indirect

relevance to counterterrorism. In the area of communications, it is participating in an interagency law enforcement

effort to standardize communications for multiagency

operations. This is mainly aimed at drug enforcement and

is being coordinated by the Office of National Drug

Control Policy. The agency is also looking at ways of

tracking items (i.e., people, vehicles, contraband) by
98 ● Technology Against Terrorism: The Federal Effort

Table E-2—Allocation of FAA Security R&D Resources

Resources ($ thousands)

Fiscal year 1990 Fiscal year 1991 (requested)

Contract Manpower Total Contract Manpower Total

Explosives detection . . . . . . . . . . . 7,000 850 7,850 22,018 597 22,615

Weapons detection . . . . . . . . . . . . 1,500 300 1,800 1,500 399 1,899

Airport and system integration. . . 3,513 207 3,720 1,500 348 1,848

Total . . . . . . . . . . . . . . . . . . . . . 12,013 1,357 13,370 25,018 1,344 26,362

SOURCE: Federal Aviation Administration, 1990.

Table E-3-Allocation of FAA Fiscal Year 1990

Contract Dollars for Major Program Priorities

Contract allocations

Major program priorities ($ millions)

Thermal Neutron/Dual Sensor Support. . . . $0. 5

Vapor Portal Development . . . . . . . . . . . . . . 1.8

New Technology Explosives Detection . . . . 4.5

New Technology Weapons Detection . . . . . 1.2

Commercial Security Systems Evaluation. . 0.5

BWI Airport Demonstration . . . . . . . . . . . . . . 3.0

Other, efforts . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $12.0

SOURCE: Federal Aviation Administration, 1990.

means of satellite systems. Other efforts more closely

related to counterterrorism are the International Explosives Incident System, a repository for data related to

international incidents involving explosives; and the

international taggant study conducted under the auspices

of the International Civil Aviation Organization (see ch.

4).

U.S. Customs Service

Relevant budget: approximately $4.8 million per year

for last 3 years.

This agency does not engage in much original research

directly related to counter terrorism. However, Customs

has supported considerable work in the area of drug

detection and interdiction, some of which is of ancillary

utility to the war on terrorism. The largest portion of the

R&D money mentioned above (about $3 million per year)

has been devoted to development of a covert remote

locating system (known as Geostar). Signals from a small

device hidden on an object will be picked up by a pair of

Earth satellites. By triangulation, the location of the object

can be determined. This project is a cooperative effort

with other agencies and groups, including the TSWG.

The remaining funds go primarily into contraband and

drug detection equipment. As an example, Customs is

sponsoring the development of an automatic letter mail

examiner for the detection of heroin, cocaine, and

morphine by the use of Nuclear Magnetic Resonance.

Laboratory and advanced prototyping efforts have shown

this technology also to be amenable to explosives

detection. In a current joint Customs-FAA project,

single-sided imaging using gamma ray backscatter technology is being developed for contraband (including

explosives) detection. The system is close to acceptance.

Customs also funded and designed a mobile x-ray

capability suitable for planeside examination of baggage

and cargo. This agency also relies on other agencies, DoD

or CIA for example, which share some specific R&D

goals.

An interesting project being undertaken by Customs is

an improvement of their Advanced Passenger Information System (APIS), which is an automated system for

screening passengers. In cooperation with a number of

agencies interested in monitoring travelers (INS and DEA

for example), a large database is being assembled that

contains information on known undesirables. Through a

computer workstation, an inspector can access this

database using a name, passport, or visa number. An

enhancement that is being explored would make possible

a computer comparison of a traveler’s appearance with a

stored image of suspects.

U.S. Secret Service

Relevant budget: fiscal year 1990-a few hundred

thousand dollars

Secret Service participates in the TSWG and does not

have a large research budget, since it is more of a user than

developer. It has participated in several TSWG projects.

Further, it has, on its own, worked on perfecting a

software package that can estimate the effects of bombs

on a building of given size and construction. Specifically,

this package is designed to improve security by identifying the most vulnerable areas of a building or to provide

forensic information on the probable size and location of

an explosive from post-blast data. The output of the

computer program will aid in planning inspections of

structures before the arrival of key officials. Secret

Service officials are anxious to maintain funding for this
Appendix E--Recent Federal Counterterrorism Research Efforts: Agencies and Their Budgets . 99

project. If the risk from bomb blast could be accurately

defined, they argue, searches and guard postings could be

much more efficiently executed thereby saving time,

effort, and money.

Environmental Protection Agency (EPA)

The EPA is managing the TSWG-funded project to

develop the mobile laboratory to respond to chemical and

biological terrorist attacks, described above in this

appendix.

Interagency Intelligence Committee on

Terrorism—Community Counterterrorism

Board

This group is made up of representatives from various

agencies involved with intelligence issues. It includes a

Research and Development subcommittee that oversees

research that would aid in data analysis as well as other

areas of special interest to the intelligence community.
Appendix F

Congressional Request and Support Letters

JOHN GLENN, OHIO, CHAIRMAN

SAM NUNN, GEORGIA WILLIAM V ROTH, JR. DELAWARE

CARL LEVIN, MICHIGAN TED STEVENS, ALASKA

JIM SASSER, TENNESSEE WILLIAM S COHEN. MAINE

DAVID PRYOR, ARKANSAS WARREN B RUDMAN, NEW HAMPSHIRE

JEFF SINGAMAN, NEW MEXICO JOHN HEINZ, PENNSYLVANIA

HERBERT KOHL, WISCONSIN PETE WILSON, CALIFORNIA

JOSEPH I LIEBERMAN, CONNECTICUT 13nteil states $?knate

LEONARD wEISS. STAFF DIRECTOR COMMITTEE ON

JO ANNE BARNHART, MINORITY STAFF DIRECTOR GOVERNMENTAL AFFAIRS

WASHINGTON, DC 20510-6250

June 22, 198 9

The Honorable John H. Gibbon s

Director, Office of Technology Assessmen t

United States Congres s

Washington, D. C. 20510-8025

Dear Dr. Gibbons:

We are writing to request that OTA conduct a study to

identify and assess those technologies that could provide the

Nation with tools in the fight against terrorism.

The past two decades have seen a steep rise in terrorist

actions, often directed at U.S. targets, including civilians.

Attacks have included kidnappings, hijackings and bombings of

civilian aircraft, as well as bombings of U.S. economic or

military targets. The case of Pan Am 103 is only the most recent

and most striking of a long series of such incidents. Moreover,

statements by Iranian leaders lead us to expect that terrorist

attacks against American citizens throughout the world may

increase.

The practical difficulty of responding to terrorist

attacks has been apparent. Since terror consists of limited

actions often directed at civilians, military tactics and

technologies are frequently not applicable, either in preventing

an occurrence or in dealing with an ongoing one.

For example, highly intrusive and costly security

measures, which the military or police agencies can employ, could

make the successful emplacement of explosive devices on civilian

aircraft very difficult . But they might also paralyze air travel

and commerce, as well as intrude on many Americans’ concept of a

free society. As another example, if passengers were taken

hostage aboard an aircraft, a classic military assault to retake

the aircraft would seriously endanger the hostages.

One strong asset that the U.S. possesses is its high

level of technological development. We would like to assure

ourselves that the Nation is taking full advantage of its

capabilities in this area. While we are aware that there is no

–l00--
Appendix F--Congressional Request and Support Letters . 101

The Honorable John H. Gibbons

June 22, 1989

Page Two

technical fix for terrorism and that even the most ingenious

technologies will not prevent all attacks, technology is a vita l

tool , to be used along with intelligence-gathering, la w

enforcement, and, where required, military or para-militar y

action .

Therefore, we would like OTA to review the current

status of research, federally-funded and other, aimed at

developing counter-terrorist tools. The review should also assess

research and development that, while not explicitly developed for

counter-terrorism, might have applications in that area. It

should include, but not necessarily be limited to explosives

detectors, methods of access and perimeter control, non-lethal but

disabling weapons, incapacitating agents, and improved data

exchange on terrorism and terrorist techniques. In carrying out

this study, classified research and development activities within

federal agencies should be examined, along with open sources.

The report should assess whether federally-funded

research in this area is well coordinated and sufficiently

focused. It should also identify those areas where increased

resources would be helpful in producing positive results in the

short-term. We do not expect the study to deal with intelligence

gathering or with police or military tactics.

We anticipate that the final report will be

unclassified. However, in order to avoid putting useful material

into the hands of potential terrorists, we expect that OTA will

also produce a substantial classified annex that would accompany

the report. An interim report should be provided to the Committee

by March 1, 1990. The final report should be

than December 31, 1990.

Sincerely,

*.L

furnished no later

# Johm4Gle%n

zL”-&

William V. Roth, Jr.

P’ Chairman Ranking Minority Member

JHG/mkh
102 ● Technology Against Terrorism: The Federal Effort

CLAIBORNE PELL, RHODE ISLAND, CHAIRMAN

JOSEPH R. BIDEN, JR . DELAWARE JESSE HELMS, NORTH CAROLINA

PAUL S SARBANES. MARYLAND RICHARD G. LUGAR, INDIANA

ALAN CRANSTON, CALIFORNIA NANCY L KASSEBAUM, KANSAS

CHRISTOPHER J DODD. CONNECTICUT RUDY BOSCHWITZ. MINNESOTA

JOHN F KERRY, MASSACHUSETTS LARRY PRESSLER, SOUTH DAKOTA

PAUL SIMON, ILLINOIS FRANK H MURKOWSKI, ALASKA

TERRY SANFORD, NORTH CAROLINA MITCH McCONNELL, KENTUCKY

DANIEL P MOYNIHAN, NEW YORK GORDON J HUMPHREY, NEW HAMPSHIRE li!bmzd %tate~ $iWnate

CHARLES S ROBB. VIRGINIA CONNIE MACK, FLORIDA

GERYLD B. CHRISTIANSON, STAFF DIRECTOR

COMMllTEE ON FOREIGN RELATIONS

JAMES P LUCIER, MINORITY STAFF DIRECTOR WASHINGTON , DC 20510-6225

July 6, 198 9

Dr. John H. Gibbons

Office of Technology Assessment

600 Pennsylvania Avenue

Washington DC 20510

Dear Dr. Gibbons:

As the tragic downing of Pan Am 103 demonstrated last

year, terrorism continues to exact its toll on Americans.

Combatting terrorism remains a difficult task for all

governments, and the United States and its citizens remain a

significant target of a number of terrorism organizations.

As Chairman and Ranking Member of the Senate Foreign

Relations Committee Subcommittee on Terrorism, Narcotics and

International Operations, we are writing to request that OTA

conduct a study to identify and assess technologies that can

provide the U.S. with tools in the fight against terrorism.

In recent years, we have seen a steep rise in terrorist

actions, including kidnappings, hijackings and bombings of

civilian aircraft, as well as bombings of U.S. economic or

military targets. Statements by Iranian leaders, and reports

of continued terrorist activity by a variety of foreign

political and military organizations, lead us to expect that

terrorist attacks against American citizens throughout the

world may increase.

The Pan Am attack highlighted the difficulties of

responding to intelligence about possible terrorist attacks,

as well some of the limitations of current anti-terorrist

detection equipment.

To date, we know of no study available to the Congress

which has undertaken a comprehensive review of anti-terrorist

technologies, with a view of assisting the Congress in

determining how we can better fight terrorism.

Accordingly, we request that OTA conduct a study of

current and possible future U.S. anti-terrorism technologies.
Appendix F--Congressional Request and Support Letters . 103

2

The review would assess those technologies now in place;

review the current status of research, federally-funded and

other, aimed at -developing counter-terrorist tools; and

assess research and development that, while not explicitly

developed for counter-terrorism, might have applications in

that area.

We would appreciate the study also including a review of

the capabilities of specific technologies such as explosives

detectors and incapacitating agents. We believe it would also

be helpful for the Congress to understand the current limits

and capabilities of data collection and exchanges on

terrorism, (in terms of the technologies used to move

information from one network to another), as well as the

techniques used by terrorists in committing terrorist acts.

The report should assess whether federally-funded

research in this area is well coordinated and sufficiently

focused, and to identify those areas where increased

resources would be helpful in producing positive results in

the short-term. To carry this study out properly, we believe

OTA should rely on both classified research and development

activities within federal agencies and open sources.

We anticipate that the final report will be

unclassified. However, in order to avoid putting useful

material into the hands of potential terrorists, we expect

that OTA will also produce a substantial classified anne x

that would accompany the report. An interim report should be

provided to the committee by March 1, 1990. The final report

should be furnished no later than December 31, 1990.

We very much appreciate your attention to this request.

@M&c

4

Mitch McConnell

Ranking Member
104 . Technology Against Terrorism: The Federal Effort

ERNEST F HOLLINGS SOUTH CAROLINA CHAIRMAN

DANIEL K INOUYE HAWAII JOHN C DANFORTH MISSOURI

WENDELL H FORD KENTUCKY BOB PACKWOOD, OREGON

J JAMES EXON, NEBRASKA LARRY PRESSLER SOUTH DAKOTA

ALBERT GORE. JR TENNESSEE TED STEVENS, ALASKA

JOHN D ROCKEFELLER IV. WEST VIRGINIA ROBERT W KASTEN JR WISCONSIN

LLOYD BENTSEN TEXAS JOHN McCAIN, ARIZONA

JOHN F KERRY MASSACHUSETTS CONRAD BURNS MONTANA

JOHN B BREAUX LOUISIANA SLADE GORTON WASHINGTON l13nited ~tates $Wnate RICHARD H BRYAN NEVADA TRENT LOTT MISSISSIPPI

CHARLES S ROBB, VIRGINIA COMMITTEE ON COMMERCE, SCIENCE,

RALPH B EVERETT C HIEF COUNSEL AND STAFF DIRECTOR

WALTER B McCORMICK JR MINORITY CHIEF COUNSEL AND STAFF DIRECTOR

AND TRANSPORTATION

WASHINGTON, DC 20510-6125

August 3, 1989

The Honorable John H. Gibbons

Director, Off ice of Technology Assessment

United States Congress

Washington, D. C. 20510-8025

Dear Dr. Gibbons:

The bombing of Pan Am Flight 103 last December is only

the most recent in a series of attacks on American civilian

aircraft by terrorists. Given our jurisdiction over aviation

security, we are concerned about protecting the safety of

American travelers at home and abroad, particularly with

respect to utilizing the most effective advanced technologies

for airport security screening.

Although we are aware that there is no certain technical

fix for terrorism, we would like to assure that the Nation is

taking full advantage of its technological capabilities.

Accordingly, we request OTA to review the current status of

Federally-funded and other research aimed at developing tools

for providing airport security.

The study should assess research and development on

explosive detection devices, including those capable of

detecting very small amounts of explosives; methods of access

control; human factors; and improved data exchange.

Classified research and development activities within the

Federal agencies as well as other sources should be

examined. The study should also address the degree to which

Federally-funded research in this area is coordinated and

focused, as well as those areas where increased resources

might help to bring positive results in the short-term.
Appendix F--Congressional Request and Support Letters ● 1 0 5

- 2 -

We anticipate that the final report will be

unclassified, with the option of a classified appendix. It

would be helpful to the Committee to have an interim report

in the spring of 1990, with the final report submitted by the

end of 1990.

Sincerely,

ERNEST F.

&oR+

Chairman

●

Chairman

Aviation Subcommittee

kc~TA_&?.?.

Ranking Minority

kM~”

Ranking Minority
106 ● Technology Against Terrorism: The Federal Effort

IMited $tates scIIate

SELECT COMMITTEE ON INTELLIGENCE

WASHINGTON, DC 10510-6475

June 7, 1990

SSCI #90-2534

Dr . John H . Gibbons

Directo r

Congress of the United States

Office of Technology Assessment

Washington, D. C. 2051O-8O2 5

Dear D r . Gibbons:

We understand that the Office of Technology Assessment

is currently engaged in a study o f the uses of technology to

combat terrorism. This study is being “conducted at th e

request o f the Senate Governmental Affairs Committee, the

Senate Commerce Committee s Subcommittee on Aviation, and the

Subcommittee on Terrorism, Narcotics and International

Operations of the Senate Foreign Relations Committee. It is

our understanding that the study will include an-examination

of federal research and development efforts in this area.

The Senate Select Committee on Intelligence endorses the

requests of these committees and strongly supports this work,

which, we hope, will provide useful information in assessing

the effectiveness and the degree of interagency coordination

of such activities.

Accordingly, the Senate Intelligence Committee wishes to

be kept fully informed of the progress of OTA’S work on this

project and to receiv e related publications and briefings a s

soon as they are available . The point of contact on ou r

staff is Charles Battaglia at 4-1765 .

Sincerely,

David L. Boren

Chairman

4! w“ iam S. Cohe n

Vice Chairman