A U.S. Department of Energy laboratory operated by Iowa State University

Inquiry

SCIENCE AND

TECHNOLOGY

AT THE

AMES

LABORATORY

AMES LABORATORY

Computers gang up

page 13

All-around tool

page 8

Second to diamond

page 1
Inquiry is published annually by

the Ames Laboratory Office of

Public Affairs. Iowa State

University operates the

Laboratory for the U.S.

Department of Energy under

contract W-7405-Eng-82. Located

on the ISU campus, the Ames

Laboratory is a member of the

university’s Institute for Physical

Research and Technology, a

consortium of research and

technology development and

transfer centers.

Editor

Steve Karsjen

Managing Editor

Saren Johnston

Art Director

Michael Marti

Photographer

Dennis Sailsbury

Contributing

Photographer

Mark Davitt

Copyright 2000 by Ames Laboratory.

All rights reserved. For additional

information about Ames Laboratory

or topics covered in this

publication, please contact:

Editor, Inquiry

Ames Laboratory

111 TASF

Ames, Iowa 50011-3020

(515) 294-9557

www.external.ameslab.gov

I

t was with great pride that we introduced Secretary of Energy Bill Richardson to the Ames

 Laboratory since we last published Inquiry. Although his visit was short, we were able to provide

him an excellent overview of our latest research in the materials, biorenewable resources and highperformance computing areas, and to demonstrate our continued commitment to conducting the

highest-quality work for the lowest-possible cost. The comment the Secretary made during his visit

that left the most lasting impression with many of us was when he said that not only does he want to

see the Ames Laboratory continue, but that it should grow. We are eager to help him achieve that

goal.

 A second significant event of the year for the Ames Lab came shortly after the Secretary’s visit,

with the signing of a new five-year contract for the continued operation of the Laboratory. As the

signatures were being put on the dotted line, the Lab was once again enjoying an “outstanding” rating

from the Department of Energy for our

scientific research, a fact which played a

key role in the issuing of the new contract.

 But we can never be content to rest on

our laurels. Science is, to a large degree,

about new discoveries – looking outside

the box, to use today’s catch phrase, to

find interesting solutions to old and new

challenges. Some of those challenges and

our scientists’ efforts to solve them can be

found in the stories in this issue of Inquiry.

I invite you to read about our discovery of

the properties of what appears to be the

second-hardest bulk substance after

diamond. The compound could be a

lower-priced alternative to the materials

now used by industry to rapidly cut and

grind the hardest steels.

 Also in this issue, learn about the

“Octopus,” a cluster of 18 computers that

can do the work of a much more costly

supercomputer. You can also go to

the “extreme” and learn about our new low-temperature, high-pressure and high-magneticfield environment that subjects materials to extreme conditions. This testing helps

determine the properties of materials under conditions they may have to experience

in actual industrial applications.

 Key to research at the Ames Laboratory is our multidisciplinary approach

to science. We are constantly linking our scientific expertise, facilities and

equipment in new and innovative ways to help find solutions to our

nation’s energy problems. We take pride in our accomplishments

thus far and look forward to the challenges ahead.

Andreja Bakac injects a sample of saturated hydrocarbons

she wants to oxidize into an aqueous solution of uranyl ions.

The uranyl absorbs light that provides the energy to drive the

oxidation experiment, making the otherwise lifeless

hydrocarbons more reactive. (see story page 17)

(back cover) After being placed in the concave top of one of

these drop-casting copper split-molds, an alloy button can be

heated in an arc-melting system until molten. The molten

material then “drops down” into the mold cavity. Once the

alloy has cooled, the split-mold is opened to retrieve the

desired shape.

Tom Barton (right) presents Secretary Richardson with a plaque

containing ultrapure metals made at Ames Laboratory.
Researchers

create

second-hardest

bulk substance

after diamond

Researchers Bruce Cook (left) and Alan Russell

By Susan Dieterle

Inquiry 1

2000

The small piece of material resting in associatescientist Bruce Cook’s palm isn’t much to look at.

If anything, it appears to be a shiny, charcoal-gray

shirt button without any holes.

 But this rather drab-looking compound has one

dazzling characteristic – it is the second-hardest bulk

substance after diamond.

 And better still, it is expected to be less expensive

than the material that now ranks a close third but is

nearly as costly as gold.

 Cook and two colleagues, associate scientist Alan

Russell and assistant scientist Joel Harringa, developed

the new material by introducing a small amount of

silicon and other additives to an alloy of boron,

aluminum and magnesium.

 With test results that confirm the hardness of the

material, nicknamed BAM, the researchers now hope

to expand their research on two fronts. First, they

want to further investigate the material’s properties

and find out whether other combinations of additives

might make it even harder. And second, they want to

determine how BAM can be produced in large quantities for industries that use ultrahard materials for

coating, grinding and machining applications.

 “What we’re trying to do is combine fundamental

science with an opportunity to improve industrial

competitiveness in a number of key areas,” Cook says.

“We’re hoping that this material will do that.”

 If the Ames Laboratory scientists succeed in

resolving some of the questions surrounding the

compound, the discovery could mean huge savings

for manufacturers who use these types of materials in

abrasives and cutting tools.

Diamond drawbacks

 Diamond, which has a measured hardness of

between 70 and 100 gigapascals (the equivalent of

10.2-14.5 million pounds per square inch), costs

about $2,000 per pound in powder form. But it can’t

be used for cutting and grinding steel because it

reacts by slowly dissolving into the iron when

brought into contact with iron-based materials at high

temperatures. In the high-speed grinding that takes

place in the auto industry, for example, friction

between the steel and the tool produces surface

temperatures as high as 1,000 C (1,800 F).

 When industries need an abrasive material that

works fast and cuts deep into specially hardened

martensitic steels, they rely on cubic boron-nitride,

which has a hardness of about 45 GPa (6.5 million

psi). Cubic boron-nitride doesn’t have the iron

reactivity problem of diamond, but it costs anywhere

from $1,500 to $7,000 per pound because it is

produced under conditions of extremely high temA of a Discovery
Inquiry

2000

2

peratures and pressures.

 “The fact that industries are willing to pay that

price for certain uses gives some insight into what a

critical industrial process this is,” says Russell, a coinvestigator on the project. “Cutting iron and steel is

an enormous part of the U.S. manufacturing

economy.”

 The BAM compound measures slightly harder than

cubic boron-nitride at about 46 GPa (6.7 million psi)

and is estimated to cost around $700 per pound. That

could substantially reduce the cost of the cutting and

grinding tools, enabling manufacturers to trim their

production costs.

 “The consumer doesn’t see the costs of these

materials up front, but it definitely affects the overall

price of the product,” Russell says.

Hard luck

 Cook discovered the hardness of the boronaluminum-magnesium compound by accident. He

was researching its thermoelectric properties in 1992

when he discovered that he couldn’t cut the samples

he’d made. “We have precision diamond saws in the

lab that can cut virtually anything, and we weren’t

able to cut this material,” Cook says. “That caught

our attention.”

 Although the existence of the baseline compound

had been known for awhile, the Ames Lab scientists

found that the material’s mechanical properties hadn’t

been fully investigated. “When Bruce discovered the

hardness, it was unexpected and something that no

one had thought to look for previously,” Russell says.

 It was also an unlikely candidate for a hard

material because of the structure of its unit cell, or

fundamental building block. “A diamond has eight

carbon atoms in a unit cell. It’s a very simple, highly

symmetric structure,” Russell explains. “This material

has 64 atoms in the unit cell. If you gave this structure to a panel of experts and asked if it would be

hard, they’d say, ‘Nah, the crystal structure is all

wrong.’ But it’s extremely hard. And that’s the kind

of thing that gets scientists salivating.”

 Cook says the complexity of the chemical structure

offers a number of possibilities to vary its physical

properties, such as enhancing the compound’s

hardness by substituting elements such as silicon.

“We thought we might be able to change the bonding

environment if we added silicon to the structure, and

it worked. It made the material harder,” he says.

 “We would expect that by tweaking the composition, we may be able to push the hardness up a little

higher,” he adds. “This was the first additive we tried,

and it produced a material that’s right up there with

cubic boron-nitride. But there may be other variations that could further increase the hardness of this

material.”

 To better understand the reasons behind the

material’s hardness, band-structure calculations are

being made by Bruce Harmon, deputy director of the

the Ames Laboratory and director of the Lab’s Condensed Matter Physics Program, and scientists in his

group. With this information, Cook, Russell and

Harringa could develop expectations as to which

chemical additions would result in the ultimate

hardness of the material.

 “When the baseline compound was first synthesized in the late 1960s, the computational power to

analyze the electronic properties of such a complex

structure simply did not exist,” Cook explains. “Only

recently has the ability to tackle such a complex

system existed. Even so, a 64-atom unit cell is an

extremely challenging theoretical problem.”

Encouraging results

 To find out how BAM would fare in a real-world

setting, the Ames Lab scientists sent samples to

Autodie International, a Michigan company that

The substance could be used in cutting and machining

applications, such as the surface of this grinding wheel.
Inquiry 3

2000

manufactures tools, dies and molds for the

automotive industry. Autodie reported

favorable results in its initial tests, Cook

says, adding that the company was especially pleased that the material didn’t

fracture – a common problem for many

cutting tools, which are often brittle.

 Cook adds that hardness is not the only

material property of interest. Wear resistance, toughness, hardness at high temperatures and how well it conducts heat are also

important factors affecting the viability of

BAM in industrial applications.

 During 1998, the scientists used a oneyear Department of Commerce grant from

Iowa State University’s Center for Advanced

Technology Development to study the

material and possible additives to enhance

its hardness. They also received a small

grant through the Roy J. Carver Trust.

 The researchers are now looking for

additional funding for a more extensive

study of BAM’s preparation and properties.

Among their research priorities are a better

scientific understanding of the material itself

and determining how best to produce large

quantities of it.

 They also want to investigate the possibility of producing the material as a uniform powder that

could be deposited as a wear-resistant coating on

surfaces such as bulldozer blades and mining tools.

“We know that the two other hardest materials won’t

tolerate it,” Russell says. “This one might.”

 He says initial tests show that BAM’s coefficient of

thermal expansion – the change in a material’s length

in response to temperature changes – is close to that

of iron, which indicates that a coating of the material

might adhere well to steel.

Growing interest

 The BAM compound is generating quite a buzz

among scientists and manufacturers. Russell notes

that researchers from Ames Lab and other facilities are

exploring the compound’s properties on specialized

equipment at Stanford University and DOE’s Argonne

National Laboratory.

 In addition, more than 70 industry representatives

have contacted Cook and Russell about a diverse

assortment of possible uses for the material, such as

testing-probe tips and wire guides for the microprocessor fabrication industry; wear-resistant linings for

the petroleum and mining industries; and thin coatDiagram courtesy of Bruce Harmon

The complex crystal structure of the baseline AlMgB compound

without any additives is pictured above. The boron atoms are blue,

the aluminum atoms are green and the magnesium atoms are red.

ings for cutting tools.

 “We’re excited about the level of interest in this

material and the wide range of applications that it

could possibly be used for,” Cook says. “We want to

continue our research so that we can give these

companies the information they need in order for

them to determine how they could use the material.”

 Part of that effort involves devising a method for

producing larger quantities of the compound instead

of the small disks they’ve been using for research

purposes.

 “Based on the work we’ve done to this point, we

feel confident that we can resolve the remaining issues

and keep moving forward,” Cook says. ❋

For more information:

www.external.ameslab.gov/news/boride.html

Research funded by:

U.S. Department of Commerce

Roy J. Carver Trust

DOE Office of Basic Energy Sciences’ Process Science

 Initiative
Inquiry

2000

4

(left to right) Karl Gschneidner, Vitalij Pecharsky and

Bruce Harmon have giant hopes for the gadoliniumsilicon-germanium alloys.

The news about materials that

scientist Vitalij Pecharsky

and senior metallurgist Karl

Gschneidner Jr. have studied for

the past five years keeps getting

bigger and bigger.

Originally noted for their

potential in magnetic cooling and

freezing applications, the gadolinium-silicon-germanium alloys are

now known to possess properties

that could be useful in sensors and

energy-conversion devices. But

first, scientists need a better

fundamental understanding of the

alloys and why they respond so

dramatically to changes in temperature and magnetic field.

To answer those questions

about the Gd-Si-Ge alloys and

several closely related materials,

the Department of Energy has

awarded a four-year research

project to a team of Ames Lab

metallurgists, physicists and

chemists led by Gschneidner and

Pecharsky. Total funding depends

on final DOE budget figures, but

could be up to $1 million a year.

“These alloys could be among

the most significant materials of the

new millennium,” Pecharsky says.

“I’m sure that we’re in for many

more surprises and interesting

phenomena in the next four years.”

In 1995, Pecharsky and

Gschneidner began exploring the

possibility of using Gd-Si-Ge alloys

in magnetic-refrigeration technology and almost immediately

discovered the alloys possessed a

giant magnetocaloric effect,

meaning they heat when magnetized and cool when removed from

a magnetic field to a much greater

extent than other known alloys.

That property made the alloys

strong candidates for magnetic

cooling and freezing applications.

After filing for a patent, the

scientists announced their discovery in 1997.

Since then, researchers here

and throughout the world have

discovered that the materials also

possess giant magnetoresistance

(a change in the magnetic field

triggers a change in the material’s

Ames Lab team launches broad-based effort to

 better understand promising materials

By Susan Dieterle

electrical resistance) and colossal

magnetostriction (the shape or length

of the material changes in response to

magnetic forces).

Simply put, a relatively small

change in the magnetic field surrounding the material produces a

tremendous change in its temperature, dimensions and electrical

resistance.

“Some materials possess one

or two of these properties, but

what’s unique about this material is that all three changes take

place in the same alloy and all three

changes are quite large – among the

largest ever seen,” Gschneidner says.

That combination of properties

and responsiveness makes the alloys

potentially useful in energy-conversion devices, such as systems that

transform magnetic energy into

mechanical energy and vice versa,

and in sensors. Pecharsky says most

sensor materials are only effective in

certain temperature ranges, but these

alloys can be tailored to respond at a

variety of temperatures.

In late 1999, the DOE asked its

national laboratories to submit

competitive research proposals

involving complex, advanced materials. The goal of the competition was

to select one or two projects for indepth research that would enable

scientists to understand how these

types of materials could be used in

the future.

Pecharsky, Gschneidner and eight

other Ames Lab researchers submitted

a proposal to study the Gd-Si-Ge

alloys. The other principal investigators are Vladimir Antropov, Scott

Chumbley, Bruce Harmon, David

Jiles, Tom Lograsso, Gordon Miller,

John Snyder and Constantine Stassis.

This July, the team was notified that

its proposal had been selected for

funding.
Inquiry 5

2000

“We have learned a lot about

the properties of this material to

date, but we need to understand

what causes the extraordinary

responsiveness of this and related

materials,” Pecharsky says. “That’s

what this project is about.”

The team will explore the

properties of the Gd-Si-Ge alloys

and many closely related materials.

The scientists will also develop

theories and models that detail the

relationship between the composition, structure and properties of

the alloys. The models and

theories could then be used to

engineer the materials for specific

applications in the future.

Pecharsky will oversee the

experimental portion of the

research, and Harmon, deputy

director of Ames Laboratory and

director of the Condensed Matter

Physics Program, is in charge of

the theoretical work. Gschneidner

will serve as project manager.

The three scientists agree that

the Gd-Si-Ge alloys are uniquely

suited to this type of in-depth

materials research. “It has been

clear for a very long time that the

physical properties are indeed

related to both the composition

and structure of any material.

What has been a mammoth task is

to understand how,” Gschneidner

says.

Pecharsky adds that because

clear-cut connections have already

been established between the

chemistry, crystallography and

magnetism of the Gd-Si-Ge alloys,

the Ames Lab group is confident

that it can succeed in understanding how those properties become

so interconnected.

Gschneidner says when

scientists understand that process,

“we will be ready to make a step

having tremendous importance –

designing a material with predicted

properties and behaviors. That’s a

dream come true for any scientist

involved with materials.”

Part of the funding will be

spent on a customized X-ray

powder diffractometer, which will

help show how changes in temperature and magnetic field affect

the alloys. The equipment will

give Ames Lab the unprecedented

ability to study changes in the

material’s crystal structure at a

variety of temperatures as the

strength of the magnetic field is

altered.

“We’re counting on traditional

techniques and nontraditional

techniques, in the form of the new

and quite unique equipment, to

help us understand this material,”

Pecharsky says. “I think we’ve

proposed an extensive and very

interesting route to advance the

basic studies of these materials.”

Harmon notes that the

multidisciplinary nature of the

Ames Lab team is a definite

advantage.

“These are fascinating materials

with complex crystal structures and

a remarkable combination of

magnetic and mechanical properties,” Harmon says. “This new

funding offers a great opportunity

to utilize and extend Ames

Laboratory’s internationally recognized expertise in the area of rareearth magnetic materials.”

Pecharsky says he and

Gschneidner consider themselves

fortunate that so many other

scientists around

the world are

interested in the

alloys.

“After we

first published

our findings

about the giant

magnetocaloric

effect in the

materials, there

were still many

unanswered

questions about

the unusual

features that were

seen in both the

magnetic properties and the

crystallography. Other people

started looking at the materials

with interests far away from

magnetic refrigeration,” Pecharsky

says. “As they started looking at it

and we continued our research,

the bigger and bigger picture

started coming out.

“It’s good to know that something you’ve discovered is considered important by your peers.” ❋

For more information:

Karl Gschneidner, (515) 294-7931

cagey@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

(left to right) The charts depict the colossal magnetostriction, giant magnetoresistance and giant

magnetocaloric effect of the Gd-Si-Ge alloys.
Clean

Atomic simulations show length

 of laser pulse is crucial in

 laser ablation of diamond

By Saren Johnston

the electrons, so the interactions

are best described by quantum

mechanics. But full quantum

mechanics calculations are too

complicated for atomic systems

containing large numbers of atoms.

“The idea of TBMD is to keep

the spirit of quantum mechanics

but simplify the process by developing a model for molecular

dynamics simulations that can

describe atomic interactions

accurately, yet is fast enough to

treat systems with large numbers of atoms,” says Wang.

Wang’s and Ho’s research

on TBMD won a Department

of Energy Materials Sciences

Award in 1996. Using TBMD,

they have created simulations

to investigate such phenomena

as carbon clusters and

buckyballs, and amorphous

forms of carbon and silicon.

They have successfully developed other TBMD schemes

to simulate how carbon atoms

behave in different environments and under different

circumstances.

Iowa State University

researchers, lead by mechanical

engineering professor Pat Molian,

wanted to better understand what

they were observing in their

laboratory experiments on laser

ablation of diamond. So Molian

decided to contact Wang and Ho.

He was hoping to interest the two

physicists in doing some unique

TBMD simulations that would

describe what was going

on at the atomic level

during diamond ablation

with laser pulses of

different durations.

The long and

short of it

Diamond is popular

within the microelectronics

and tool-making industries

because of its unique

properties. It is the

hardest material known

and has the highest thermal

conductivity. It also has a large

bandgap that makes it transparent

to light in the ultraviolet range.

However, the very properties that

make diamond such a useful

material also make it extremely

difficult and expensive to machine

– a predicament that Molian thinks

could be remedied with pulsed

laser technology.

Pulsed lasers provide what

scientists call peak power – the

amount of power delivered during

a single pulse of laser energy.

Pulse width, or duration, greatly

affects the peak power of a laser

because it defines the amount of

time the material being studied

interacts with the light. Pulse

widths of longer durations are

generally associated with lower

intensity lasers and longer periods

Using an atomic simulation he developed, Cai-Zhuang Wang

demonstrates how carbon atoms (purple circles) are peeled

from the diamond surface in a layer-by-layer fashion when

subjected to femtosecond laser pulses.

Inquiry

2000

6

Cai-Zhuang Wang and Kai-Ming

Ho tend to view materials as

marvelous collections of atoms and

electrons. As theoretical physicists,

they rarely investigate a solid

chunk of material sitting on a

workbench, preferring instead to

explore the material at the atomic

level – a world teeming with

activity.

The two Ames Laboratory

researchers devote their efforts to

describing this activity and understanding why atoms interact the

way they do in specific situations.

The atomic simulations they

develop help explain the “why”

behind what experimentalists

observe in the laboratory.

Over the last 10 years, Wang

and Ho have developed a method

for doing quantum molecular

dynamics simulations of practical

materials with far more ease, speed

and economy than is possible with

conventional first principles

methods. The technique, called

tight-binding molecular dynamics,

is a computationally efficient

means of studying the structures,

dynamics and electronic properties

of complex systems at the atomic

level. And TBMD can accommodate changes in bonding within a

material due to electronic excitation, a capability that most atomic

simulation methods don’t possess.

TBMD – a “simple” plan

Wang explains that the interactions between atoms originate from
both before and after

femtosecond laser ablation

showed similar peaks, indicating

clean surfaces free of graphite

contamination. The femtosecond

laser pulse had made a clean

sweep, removing the top layers

of diamond atoms.

Ah – those “whys and

wherefores”

“We were very anxious to

learn why the femtosecond lasers

did so much better than the

nanosecond lasers. We could see

what was happening, but we didn’t

know why,” says Molian.

Ho says, “They came to us to

see if we’d do some simulations

that would tell them what was

happening atomically – what was

taking place on the diamond

surface and why the femtosecond

and nanosecond laser ablation

processes resulted in different

structures.”

Wang explains, “It usually

takes a picosecond for the energy

from the laser-excited electrons to

reach the atoms. (A picosecond is

one trillionth of a second, or 10-12

second.) When diamond is

irradiated with nanosecond laser

pulses, the laser is intense at 10-9

second, and the atoms can be

thermally excited. This leads to

melting and the formation of lightabsorbing graphite residues that

contaminate the surface layers.”

On the other hand, the

femtosecond laser pulse is much

shorter than the time required for

an atom to vibrate, so it is able to

eject the electrons into highly

excited states while the atoms are

still thermally cool. The energy

stays in the electron system. The

TBMD simulation shows that

femtosecond laser ablation peels

atoms from the diamond surface in

a layer-by-layer fashion through a

non-thermal mechanism, leaving a

smooth diamond surface.

“The femtosecond laser leaves

a very clean cut,” says Ho. “With

the different amount of energy that

is input, there is more surface

removed.”

The conventional view of

material removal by laser is that the

material is heated, melts, becomes

a liquid or a gas and goes away,

Wang explains. “However,” he

continues, “the physics involved

with the femtosecond laser is

different than the normal melting

picture because the time scale is

not long enough to allow the atoms

to vibrate. That is some new

physics, and the reason why Dr.

Molian and his colleagues came to

us for the research and TBMD

simulations that would help them

better understand that process.

Our models correlate very well

with their experimental findings.” ❋

For more information:

Cai-Zhuang Wang, (515) 294-6934

wangcz@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

of light exposure, while pulse

widths of shorter durations are

associated with higher intensity

lasers and shorter light exposure,

characteristics essential for highprecision laser machining.

Molian and his colleagues have

been investigating the use of

ultrashort pulsed lasers for

micromachining diamond in their

laser ablation experiments. They

observed that ablation with nanosecond (one billionth of a second,

or 10-9 second) or longer laser

pulses caused graphite formation

and contaminated surfaces. The

researchers discovered the graphite, or “diamond dirt,” by using

Raman spectroscopy, which detects

the vibrations in a material. Before

nanosecond laser ablation of

diamond, the Raman spectra

displayed characteristic peaks. But

the peaks had disappeared in the

spectra produced following

nanosecond laser ablation, indicating that the surface was no longer

diamond in structure.

“Graphite formation is a big

issue for many applications,

especially electronics, where they

don’t want any contamination,”

says Molian. “So we moved on

from nanosecond to femtosecond

laser technology.” (Femtosecond

pulses are one quadrillionth of a

second, or 10-15 second long.)

The switch to the ultrashort

femtosecond pulse proved beneficial. The Raman spectra produced

Inquiry 7

2000

Cai-Zhuang Wang (right) and Kai-Ming Ho often construct

and study three-dimensional models in the process of

creating computer simulations to describe atomic activity.

(left) Wang’s and Ho’s TBMD simulations reveal that femtosecond laser pulses peel

carbon atoms (purple circles) layer-by-layer from the diamond surface, leaving a

smooth surface after ablation.

(right) TBMD simulations show that nanosecond laser pulses cause thermal melting,

resulting in graphite residue (purple circles) that anchors to the diamond surface

following ablation.
At last, MUCAT has seen the light!

After 10 years of planning and construction, and a

whole lot of problem-solving, the undulator beam line

developed by the Midwest Universities Collaborative

Access Team is up and running at Argonne National

Laboratory’s Advanced Photon Source near Chicago.

“The beam line is operational. We’re actually at

the point where we’re taking data, getting results and

writing papers,” says Alan Goldman, an Ames Laboratory senior physicist and chair of the Iowa State

University physics and astronomy department. He

heads MUCAT, a group of scientists from eight universities and one German institute that was organized in

1990 to develop a sector at the APS.

The APS provides MUCAT scientists and members

of other collaborative access teams with a means of

tapping into some of the strongest X-ray beams in the

world. Goldman and his MUCAT colleagues can use

the brilliant, highly focused X-rays produced by the

APS third-generation synchrotron radiation source to

investigate the molecular make-up of all kinds of

materials, ranging from magnets, ceramics and soils to

proteins, drugs and asteroid dust.

“The APS is an incredibly versatile tool that allows

you to see microscopic details of materials with

extremely high resolution,” says Goldman. “It can be

used by almost any group interested in looking at the

structure of materials. Most significantly, because it

has wide applications to so many fields, it allows for

collaborative research efforts among different disciplines.”

Running in circles

The APS synchrotron operates round-the-clock,

generating electrons and accelerating them to energies

approaching the speed of light. In just a quarter of a

second, the electrons can make 200,000 trips around the

synchrotron’s 368-meter circumference (approximately 405

yards) as they climb to energies approaching 7 billion

electron volts.

From the synchrotron, the electrons are injected into a

giant storage ring about two-thirds of a mile in circumference. The storage ring is constructed as a set of curves

connected by straight sections. Once inside, the electrons

travel in a concentrated beam, circling the ring more than

271,000 times per second. The electron beam is guided

and focused by hundreds of powerful electromagnets that

keep it moving in a circular path.

Researchers have optimum access to the beam through

the experiment hall, which surrounds and is separated

from the storage ring by a shielding wall. The experiment

hall consists of 35 sectors, which serve as laboratory space

for the collaborative access teams using the APS.

“Each sector in the APS really consists of two beam

lines that tap the synchrotron radiation produced by the

storage ring’s electron beam,” says Goldman. “The

insertion device beam line contains powerful permanent

magnets that have been placed in the straight sections of

the storage ring to either wiggle the beam back and forth

or make it undulate – this is how you get synchrotron

Ames researchers are

tapping into the brilliant

X-rays at Argonne’s

Advanced Photon Source

New Life at the Light Sourceby Saren Johnston Light

photo courtesy of Argonne National Laboratory

Inquiry

2000

8
equipment that will allow Goldman and other MUCAT

members to carry on a diverse assortment of research

projects. An instrument currently in operation in

station 1 is the four-circle diffractometer. Goldman

and his Ames Lab colleagues are using the diffractometer to perform magnetic scattering measurements

and to study X-ray diffraction from single crystal

samples produced at the Lab. The work has brought

new information to light about the magnetic structures

of the compounds from which the crystals were produced, as well as revealed new magnetic transitions

that did not show up under traditional measurements.

Station 1 is also the home of a novel piece of

equipment that is one of only a few in the world.

The liquid surface reflectometer developed by Ames

Lab physicist David Vaknin will be used in conjunction with the powerful APS X-rays to investigate the

structure of ultrathin layers of organic materials that

may one day be used in novel optical, electronic and

biological devices.

Small furnace is hot item

A piece of equipment being tested in station 1 on

the MUCAT undulator beam line is a new compact

furnace designed by Goldman and Ames Lab researchers Bill McCallum, Matt Kramer, Kevin Dennis

and Larry Margulies (see story page 11). The furnace

allows high-temperature powder diffraction studies of

complex materials at various temperatures and under

the same processing conditions that exist in the

laboratory environment. The resulting diffraction

patterns reveal what happens to the crystal structure

Inquiry 9

2000

radiation. But the act of turning the beam around the

corner by a bending magnet will also produce synchrotron radiation, so each sector also has a bending

magnet beam line,” he explains.

The bends, wiggles and undulations produced by

the bending magnets and insertion devices alter the

electron beam’s course and allow it to navigate the

straight-aways and curves of the storage ring. As its

path changes, the beam sheds synchrotron radiation in

the form of X-rays that range in power from 1 kilovolt

to hundreds of kilovolts. By way of comparison,

Goldman says that standard medical X-rays have an

energy of 50-60 kilovolts.

Setting up in sector 6

Although the undulator beam line in MUCAT’s

sector 6 is now working, Goldman says it’s difficult to

pinpoint the exact date it became operational.

“There’s a constant effort in commissioning that

goes on when you’re getting beam. And there are lots

of problems to solve on these lines because they’re

extraordinarily complicated,” he says.

Fortunately for Goldman and the rest of the

MUCAT scientists, they have an outstanding group

of trouble-shooters to count on. Doug Robinson,

an Ames Lab physicist, is in charge of operations

at the beam line. “More than anyone, Doug has

really made that thing work,” says Goldman. He

adds that Ames Lab assistant scientist Eric Zoellner

has been at the beam line since the beginning of

construction. “Eric has had an awful lot to do

with its success, as has Didier Wermeille, a

postdoc in my group who’s been working on the

beam line for about two years.”

The building process for sector 6 started from

the ground up, or put more accurately, from the

wall out. “What the APS gives you in the very

beginning is a hole in the wall,” says Goldman with

a grin. “Basically, what you get to start with is a

beam pipe and a flange at the end. You have to

build everything else outside to access the storage

ring’s electron beam.”

Everything else includes a lot of expensive

equipment, so sector 6 is coming together bit by costly

bit. There’s an enclosure for the optical systems that

condition the X-ray beam so researchers can use it in

the experimental station. “All of the instruments and

equipment in the optics enclosure condition the beam

so we get something clean coming down the pipe and

into the experimental enclosure, which is about 50

meters from the storage ring,” explains Goldman.

The MUCAT undulator beam line consists of two

experimental stations that operate in tandem. And

those stations are slowly filling up with the kinds of

APS Collaborative Access Teams

diagram courtesy of Argonne National Laboratory
as a material heats and cools, information needed to

better understand and control the microstructure of

new materials.

“I expect the new compact furnace will be one of

the most popular instruments on the beam line

because it’s really rather unique,” says Goldman. He

explains that the idea was to scale down a basic tube

furnace design and make it fit on the four-circle

diffractometer to take advantage of the high-energy

X-rays produced by synchrotron radiation. “You can

control the furnace temperature up to 1,500 C (2,732 F)

and also spin the sample in such a way that there are

no preferred orientation effects. It’s worked quite

nicely,” he adds.

Always room for more

In addition to the equipment already in place,

researchers in sector 6 will soon be able to make use

of a new surface science chamber. Funded by the

National Science Foundation, the chamber will be

constructed in station 2 on the MUCAT undulator

beam line. It will be used to study the surface

properties of materials and surfaces that are grown

in situ using a variety of techniques.

“There’s a lot to do, but it’s going to be fun,” says

Goldman. “I like playing with complicated pieces of

equipment. And I like seeing things come together

and work.”

With any luck, Goldman will see that happen with

the special high-energy side station, which is being

funded and constructed by the German institute,

F. Z. Juelich, a MUCAT member organization. As its

name implies, the high-energy side station will sit to

the side of the main undulator beam line in sector 6.

It will operate in parallel with the beam line, supplying energies up to 120 kilovolts compared with the

main beam line’s lower energies of 3-40 kilovolts.

“The high-energy range is for experiments in

which we want to penetrate into the sample more

deeply,” says Goldman. “The low-energy range will

help us with magnetic scattering studies on actinide

materials.”

Filling up the second hole in the wall

Goldman and his colleagues have a lot on their

plates, but not so much that they can’t make room for

more, especially when it comes in the form of a

second beam line for sector 6. “We’ve been funded

to build a bending magnet beam line, which will

complement the undulator line and allow a wide

variety of standard scattering and spectroscopy

techniques to be used,” Goldman says. “This is

where the high-temperature diffractometer and the

compact furnace will live, eventually.”

Experiments planned for the bending magnet

beam line include studies of phase diagrams, in situ

investigations of nucleation and growth, recrystallization of bulk metallic glasses and processing of

high-temperature materials.

Getting the new beam line operational will mean

a lot of travel between Ames and Argonne for

Goldman, who never seems to worry about the time

or the miles. “I think one of the things that keeps me

going is that there’s this instant in time when you’re

working on a project and you finally understand, or

think you have a good way of understanding, what’s

going on in a material,” he says. “And for that

instant, you know something that other people don’t

know. So it’s just discovery itself.”

And in the end, discovery is the reason Ames

Laboratory has strongly supported the MUCAT

project, beginning with the 1990 initial planning

stages – before the APS was even built. “The Lab’s

support over the years has been just outstanding,”

says Goldman. “The APS is a remarkable tool for

synchrotron X-ray studies for the general scientific

community. And we’re going to welcome anyone to

come out and do some work.” ❋

For more information:

Alan Goldman, (515) 294-5441

goldman@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

Inquiry

2000

10

Alan Goldman (foreground, with white identification badge) heads the

group of MUCAT scientists whose collaborative efforts have brought the

MUCAT undulator beam line into operation.
Inquiry 11

2000

S h e d d i n g N e w

(left to right) Researchers Kevin Dennis, Bill McCallum and Matt

Kramer display the components of the compact furnace they designed

along with Alan Goldman and Larry Margulies.

A unique, compact furnace combined with high-energy X-rays is

giving researchers at Ames Laboratory

the unprecedented ability to directly

record the chemical and structural

changes of complex materials at high

temperatures under real processing

conditions.

This information is crucial to

understanding and controlling the

composition and microstructure of

new materials. It

previously took months

or years to collect such

data through the

laborious process of

heating, quenching and

then analyzing numerous samples. But the

Ames Lab researchers can now gather

the data in just a few days while

getting a more detailed picture of what

happens to a material’s crystal

structure as it heats and cools.

The new system is ideal for

complex materials such as structural

ceramics, superconducting wires and

nanostructured materials. The insights gained through the Ames Lab

system may speed the development of

new materials for use in fields such as

aerospace engineering, electrical

distribution systems and microelectronics.

“We’re seeing details of the

phase transitions that I don’t think

anybody has ever described before,”

says scientist Matt Kramer, who

helped design the furnace built by

Ames Lab’s Engineering Services

Group.

The furnace uses an analytical

technique known as X-ray diffraction

in which an X-ray beam is focused on

a small sample of material. The beam

is diffracted by the crystal structure of

each material, producing a unique

pattern of concentric circles, called

“Debye rings.” By capturing images

of the changes in the ring pattern as

the material is heated and cooled,

scientists gain a better fundamental

understanding of what happens to the

material’s crystal structure at various

temperatures.

In 1997, Kramer

began working with senior

materials scientist Bill

McCallum, senior physicist Alan Goldman,

assistant metallurgist

Kevin Dennis and thenAmes Lab graduate student

Larry Margulies on a design for a

compact, portable furnace that would

enable them to rotate samples during

an experiment. They also wanted to

be able to subject the samples to a

variety of environments, such as inert

or oxidizing atmospheres, encoun-

“The excellent control we have with our furnace

means that we can select an exact temperature

setting for our measurement and know that the

whole sample is that temperature.”

-Matt Kramer

By Susan Dieterle

on Advanced Materials
tered in processing conditions.

What emerged was a scaleddown version of the standard laboratory tube furnace, measuring about 18

inches in length and 6 inches in

diameter and capable of heating

samples to 1,500 C (2,732 F). The

furnace has an indirect, magnetic

coupling system that connects to a

motor shaft, which rotates the sample.

Samples are held at the end of a

long tube and aligned with a 3-

millimeter opening in the side of the

furnace. The X-ray beam enters

through the opening and the diffracted rays emerge through a slot in

the furnace.

Kramer says the new system is

an improvement over current hightemperature X-ray diffraction

systems, in which samples rest on a

flat plate. This doesn’t allow the

sample to be rotated and sometimes

causes the liquid and solid phases of

the material to draw apart. Also, the

flat-plate systems don’t always heat

the sample uniformly, producing large

temperature variations in the material

that make it difficult to correlate the

temperatures with changes in the

crystal structure.

“The excellent control we have

with our furnace means that we can

select an exact temperature setting for

our measurement and know that the

whole sample is that temperature,”

Kramer says. “And with the confined

geometry, we can melt things and

know that the liquid and solid

aren’t separating.”

In addition to the scientists

who developed the furnace,

the device has been used by Ames

Lab scientists Doug Finnemore and

Dan Sordelet as well as researchers at

DOE’s Brookhaven National Laboratory.

The experiments are conducted at

off-site facilities where high-energy

X-rays of between 35 and 100

kilovolts are available. Most of the

experiments take place at the Advanced Photon Source at the Department of Energy’s Argonne National

Laboratory near Chicago and the

Cornell High Energy Synchrotron

Source in New York.

At Argonne’s APS facility, the

furnace has now found a home on a

sector reserved for the Midwest

Universities Collaborative Access

Team, which is operated by Ames Lab

and Iowa State University (see story

page 8).

Inquiry

2000

12

The furnace is shown in the center of a

four-circle diffractometer. Beam

In

Sample Positioning

and Motion Control

Furnace

Housing

Atmospheric

Controlled Hot Zone

X-ray

Slit

Before an experiment begins, the

furnace must be aligned with the

X-ray beam – a painstaking process

because the beam itself is about 1

millimeter wide and 0.5 millimeter

high. “That’s the hard part,” Kramer

says. “The first time we did this, it

took us three days to align the

furnace to the beam and then another

hour or two to align the sample to the

beam itself. But we’ve gotten the

process down well enough now that it

only takes us about a half a day to

line it up and minutes to put the

sample in.”

The researchers

have also found that

“shuttering” the beam,

rather than using a

continuous ray, enables

them to take better

sequential images from

the diffracted rays.

Kramer says the reactions

are monitored with a time

resolution of less than two seconds,

fast enough to make a virtual movie

of images that capture the material’s

structural transformation during

temperature-driven processing.

Kramer adds that colleagues at

Argonne and the European Synchrotron Research Facilities have asked

about having Ames Lab build similar

furnaces for them. He notes that the

Ames Lab group is also willing to let

other researchers use the furnace. ❋

For more information:

Matt Kramer, (515) 294-0276

mjkramer@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences
Inquiry 13

2000

I

 t’s not impossible to find a

 needle in a haystack. If you

 have enough time – or enough

arms – it can be done. That’s more

or less the reasoning behind a

“cluster computer” designed by the

Ames Laboratory’s Scalable Computing Laboratory and built by

Iowa State University’s zoology and

genetics department. Called the

Octopus, this machine has 18

computers that function in concert

to do the work of a much more

costly supercomputer.

In this case, the “haystack” is

the huge amount of genetic data

being generated by various genome

discovery projects. The highprofile Human Genome Project, for

instance, will ultimately result in

data on the 3 billion chemical base

pairs that make up human DNA.

Researchers at ISU, working with

various colleges around the country, are dealing with similar

amounts of data with their maize

gene discovery project.

The “needles” in these haystacks are sequences of DNA, or

genes, that living cells follow to

make proteins. Those proteins, in

turn, perform the elemental work

of life.

Determining gene sequences

and how they express themselves

in genetic traits is difficult at best.

One challenge is the sheer amount

of data involved; just scanning

through the human genome data at

a rate of 100 bits per second would

take close to a year.

Another complicating factor is

that only the human genome

project can afford the brute force

method of direct sequence gathering. Even with the importance of

maize – the class of crops responsible for more than 70 percent of

the caloric value of the human diet

worldwide – researchers must

instead find more elegant, less

costly ways to crack its genetic

code. These methods involve the

use of sophisticated computer

algorithms acting on huge databases.

Bioinformatics to the rescue

The computational demands of

genomics is what led Volker

Brendel, an ISU associate professor

of zoology and genetics, to instigate the Octopus project. Brendel

is a member of the maize gene

discovery team and an expert in

the nascent field of “bioinformatics.” This relatively new

discipline taps tools and techniques from biology as well as

mathematics and computer science.

It relies on sophisticated statistical

techniques and efficient software

algorithms to interpret genetic data,

leading to a better understanding

of biological systems.

Like almost anything related to

information technology,

bioinformatics research can be

accelerated by the use of faster

computers. To be sure,

high-performance

supercomputers have the

computational horsepower

and memory needed to handle

gene data with ease. But the cost

of these systems starts somewhere

north of several hundred thousand

dollars. So instead, Brendel

considered a cluster computer to

be built using run-of-the-mill, and

therefore low-cost, personal

computer components. Soon,

Brendel was in touch with the

experts at Ames Lab’s Scalable

Computing Laboratory.

Cluster computing is one of

SCL’s specialties. Its scientists have

built or designed eight clusters for

Researchers at ISU’s zoology and genetics

department use a cluster computer built

with assistance from the Ames Lab’s

Scalable Computing Laboratory to help

unravel the gene sequence of maize.

By Robert Mills
desktop computer. Yet, the parts

are “plain vanilla,” says Halstead.

The use of these standard parts

translates into low cost, he explains, adding that each node can

also have a life after the cluster as

a desktop system for word processing and other routine computing tasks.

As for the software, “Brendel’s

algorithms are ideal applications

for cluster computing,” explains

Halstead. “The problem is fairly

linear,” which means that adding

more processors leads directly to

faster processing. The $45,000

Octopus has a theoretical capacity

of roughly 3.2 billion floating point

operations per second, which

makes it about half as powerful as

the $300,000 ALICE cluster operated by SCL in the Ames Lab.

Brendel is also planning to follow

SCL’s suggestion to add a “terminal

room” with desktop systems that

Inquiry

2000

14

Ames Lab and ISU researchers.

The SCL also runs two of its own

cluster computers, including a

$665,000 cluster of dual processor

IBM Power3 workstations made

possible via a Shared University

Research grant from IBM. The SCL

team has even written a cluster

“cookbook” that provides a how-to

on constructing PC clusters (available on the Web at

www.scl.ameslab.gov/Projects/

ClusterCookbook/).

Still, the design of a cluster is a

shade more difficult than cooking

dinner. Cluster computers achieve

high speeds by dividing the work

of the software and running

various sections simultaneously on

individual processors called

“nodes.” As such, the various

components – including processor

speed, memory and hard disk

space – need to be “balanced” for

a particular application to achieve

optimal speeds. For the Octopus,

SCL researchers ran benchmarks of

their own design to determine the

most appropriate characteristics for

the system.

The SCL also provides ongoing

assistance to Brendel’s group to

help write software that can take

advantage of the cluster. “Sticking

these machines in a room, turning

them on, and so on, is arduous but

doable. The true research aspect

that we help other groups with is

how to get their code to run in

parallel,” says David Halstead, SCL

associate scientist who is sometimes called “Clusterman” around

Ames Lab for his expertise in the

field.

Plain vanilla, but fast

Each node of the Octopus

consists of a 450 megahertz Intel

Pentium II microprocessor, 512

megabytes of memory, and a nine

gigabyte hard disk. By itself, each

would make a fairly powerful

can be used either by students as

regular computers or as additional

nodes for Octopus.

The whole situation “couldn’t

have worked out

better,” says

Brendel of the

design and building

of the Octopus,

which essentially

took about three

months. The

machine is now up

and running in

ISU’s Molecular

Biology Building.

“We are still in the

infancy of using the

machine. Basically,

we are using it to

speed up sequential code for gene

finding and annotation,” he says.

Thanks to their

low cost, cluster

computers are

becoming more

common in universities and research

institutes; in fact,

Ames Lab and ISU are home to at

least nine such systems. But most

clusters are made for physics,

engineering, weather forecasting or

just to learn more about cluster

computing. The Octopus, in

contrast, is probably one of the few

built specifically for bioinformatics,

according to Brendel. What’s more,

it’s located in the same building

where computational biologists do

their research. “It lets me stay close

to my data,” he says. ❋

For more information:

www.octopus.iastate.edu

Research funded by:

DOE Office of Basic Energy Sciences

Iowa State University

Brad Powers (left), an ISU senior in biology, and Ames

Lab’s David Halstead are shown with the Octopus, an 18-

node cluster computer they helped build for ISU’s zoology

and genetics department.
Inquiry 15

2000

You might say that David Jiles and Bill McCallumshare a mutual attraction to magnetism.

For much of their careers, the Ames Laboratory

scientists have developed magnetic materials that can

be used in innovative, energy-efficient technologies.

Their latest development is a material that may

steer automotive companies toward their goal of

lighter, more fuel-efficient vehicles.

The researchers say a 1/4-inch-thick ring of the

material could be used in an electronic torque sensor

to regulate the steering power provided to a car’s

wheels by an electric motor. This would enable

automakers to eliminate the heavy, energy-draining

hydraulic system currently used in power-steering

assists.

“Replacing the hydraulic power-steering system

with an electrical system that uses this type of sensor

should improve the fuel efficiency of a car by about

5 percent,” says Jiles, senior physicist. Lighter, more

energy-efficient vehicles would use less gasoline,

conserving fossil fuels and reducing transportation

costs, he adds.

Limited options

Jiles and McCallum, senior materials scientist,

looked at a number of possibilities during the past

five years as they searched for an inexpensive sensor

material that met the specifications of the auto industry. They say only one viable option emerged: a

composite consisting of cobalt ferrite (a compound of

cobalt oxide and iron oxide) and small amounts of

nickel and silver to hold the material together.

“I think we’ve looked into all of the possibilities,

and it’s difficult to conceive of a better material at this

time,” Jiles says. “The fact that it’s also a relatively

low-priced material makes it very attractive.”

He says current power-steering systems use a

hydraulic assist that requires continuous pressurization

in order to sense and respond to steering changes.

This produces a constant drain on the car’s power,

even when the steering wheel isn’t being turned.

“Also, the hydraulic system weighs a lot, so there’s a

significant weight reduction if you can replace it with

an electrical system,” he adds.

Sensor system

A sensor using a small ring of the cobalt-ferrite

composite would be strategically placed on the

steering column. As a driver turned the wheel, the

magnetization of the cobalt-ferrite ring would change

in proportion to the amount of force applied by the

driver. The change would be detected by a nearby

field sensor that would interpret how much force

should be applied to turn the wheels and then relay

the information to an electrical power-assist motor.

Unlike the hydraulic system, the electrical system

By Susan Dieterle

New sensor material could be part of lightweight power-steering technology

A material developed by Bill McCallum (foreground) and David

Jiles forms the dark ring in the middle of the torque-sensor

sample in McCallum's hand. The composite material

undergoes slight length changes when magnetized.

On

the

Road

to

Vehicles

LIGHTER

New sensor material could be part of lightweight power-steering technology
Inquiry 16

2000

would consume minimal energy when the steering

wheel was not being turned.

What makes the cobalt-ferrite composite ideal for

this application is a property known as magnetostriction, Jiles says. Magnetostrictive materials undergo

slight length changes when magnetized. Jiles and

McCallum take advantage of that property, but in

reverse. In their approach, the turn of the steering

wheel would apply stress to the cobalt-ferrite ring,

producing a change in the magnetic field it emits.

Cobalt ferrite maintains its magnetostrictive abilities

throughout the temperature range specified by the

auto industry, from minus 40 C (minus 40 F) to 150 C

(302 F). Jiles says that’s necessary because automakers

don’t agree on the best location on the steering

column for the torque sensor. Some want it in the

passenger compartment while others want it in the

engine compartment, where it would be subjected to

engine heat as well as winter conditions.

“High-class rust”

McCallum adds that cobalt ferrite also meets the

strength and corrosion-resistance requirements for the

sensor material. “This ceramic-metallic composite is

similar in concept to materials used in high-strength

tool bits where excellent mechanical properties are

needed,” he says. “And cobalt ferrite is basically highclass rust, so it’s hard to corrode any further.”

Jiles says the composite is also a cost-effective

choice. While other materials may rank higher in

terms of magnetostriction, they’re too costly to be used

in wide-scale production. For example, Terfenol-D is a

rare-earth, magnetostrictive compound that Ames Lab

helped develop in the 1980s. It possesses a much

higher degree of magnetostriction, but can cost up to

100 times more than the cobalt-ferrite composite.

“If you normalize the measurements based on the

cost of the different materials, you can see that our

cobalt-ferrite material is far and away the best performer,” Jiles says.

Dealing with difficulties

The five-year effort to develop an inexpensive

sensor material that met the auto industry’s needs had

its share of frustrations and setbacks. Jiles and

McCallum hit several roadblocks that sent them back

to the drawing board. As part of the development

process, they devised their own software and a unique

test bed to measure the performance of the materials

they were studying.

“We’d test some of the

materials, and they

wouldn’t respond in the

way that we had anticipated, so we would go back to understand why,” Jiles

recalls. “But now we have a practical material, and

we also have computer simulations that can tell you

how it will perform in engineering applications.”

Much of the research on the sensor material was

funded through a three-year, $820,000 grant they

received in 1996 from the Department of Energy’s

Advanced Energy Projects Division. One of the DOE’s

primary missions is to engage in research that leads to

the development of materials that improve the efficiency, economy, environmental acceptability and

safety of energy sources.

Jiles and McCallum have applied for a patent on

the cobalt-ferrite composite and plan to continue

working with automotive manufacturers interested in

using the material in an electronic torque sensor.

“When we began this project, we knew it was

possible that there might not be a material that would

meet the specifications,” Jiles says. “It’s satisfying that

we’ve gone through this long search and come up

with a material that works.” ❋

For more information:

David Jiles, (515) 294-9685

gauss@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

ferrite

ring

field

sensor

The diagram shows the sensor ring –

made of a material developed at Ames

Laboratory – on the drive shaft. As the

steering wheel turns, stress is applied to

the ring, changing the magnetization of

the material. A field sensor detects the

change, interprets how much force

should be used to turn the wheels and

relays the information to an electrical

power-assist motor.
by Saren Johnston

She studies chemical reactions – that’s her job.

The reactions she’s investigating may one day

lead to new chemicals that can be converted into

plastics and other kinds of materials, but Andreja

Bakac is focused on the fundamental chemistry that

must first take place. Because, as she says, nothing

happens without it.

The Ames Lab chemist’s special interest is

photochemistry – studying the effects of light on

chemical reactions. While many photochemical

reactions are initiated by ultraviolet light, Bakac is

using visible light to do her experiments. Her

research centers on the photooxidation of hydrocarbons to industrially important chemicals. But it’s not

just doing the chemistry that’s her concern – it’s also

doing it in a simple, inexpensive and environmentally safe way.

“Lighting up” the lifeless

Hydrocarbons are chemical compounds that are

composed mostly of hydrogen and carbon, and there

are lots of them. If you think these compounds may

not be relevant to you, think again. Each time you

fill your car with gas or adjust the heat in your home,

you might remember that petroleum and natural gas

are mixtures of hydrocarbons. In fact, petroleum

crude oil is the largest source of hydrocarbons.

Bakac’s work focuses on saturated hydrocarbons,

those that contain only single carbon-carbon bonds,

making it impossible to attach additional elements or

compounds.

“Were it not for the chemical inertness of saturated hydrocarbons, this class could become an

important feedstock for the chemical industry,” says

Bakac. “They’re so plentiful, yet so dead and

useless.” However, partial

oxidation is one way to boot them out of their

comfort zone and make them more reactive.

Chemical reactions have to be driven. Any

reactions done in the lab must be activated in some

way, and the standard method is by heat. This is

known as a thermal reaction. But light can also drive

chemical reactions and is sometimes a better choice.

Bakac explains that photochemical reactions have

some major advantages. “Light is typically a lot

cheaper than heat, and it’s perfectly clean environmentally. You simply turn on a lamp or move to the

window, and there’s your energy source.”

Of course, oxidation experiments require oxidants, chemicals that give up oxygen easily or remove

hydrogen from another compound. Strong oxidants

often oxidize things indiscriminately, pollute ground

water and are expensive and difficult to handle.

“Then you have to consider waste treatment and all

the problems associated with it,” Bakac reminds us.

Simple air is the oxidant in Bakac’s hydrocarbon

oxidation experiments. “Air or oxygen – that’s as

innocuous as oxidants get,” she says with a smile.

“That’s what’s so wonderful about these experiments

and what makes them so easy.”

In addition to light and air, Bakac’s experiments

need a photosensitizer – something to absorb the

light so it can be used in the oxidation reactions. She

uses a brilliant yellow aqueous solution of uranyl

ions. Its yellow color is what allows the solution to

absorb the visible light necessary to drive the reaction. As it absorbs light, the solution turns a neon

green. The electronic structure of the uranyl changes,

and the uranium becomes more reactive – a condition

known as the excited state. The light makes a more

Scientists may one day

be using energy from

light to activate sluggish

hydrocarbons

Inquiry 17

2000

Excited uranium serves

as a photosensitizer,

absorbing visible light

to drive the partial

oxidation of saturated

hydrocarbons.
energetic uranium that can photocatalyze, or set off,

the oxidation of hydrocarbons. Left on their own,

Bakac says the hydrocarbons would likely never react,

and if they did, the reaction would be so out of

control that it would produce many different products.

“Uranyl both increases the reaction rate at which

hydrocarbons are oxidized and channels the reaction,

leading to improved selectivity in the final product.

We’ve gotten one major product in each of the

reactions we’ve looked at,” says a pleased Bakac.

“The way we conduct these experiments is so

simple, inexpensive and safe,” she continues. “We

take a hydrocarbon and uranyl, dissolve them in

water, bubble some oxygen or air through the solution, and turn on the lamp. During the reaction, we

withdraw samples to monitor product formation.”

Bakac notes that the word “uranium” is the only

disadvantage of the hydrocarbon photooxidation

reactions. “People are afraid of the word because

they associate it with radiation pollution,” she says.

“The fact is, there is no reason to worry because in

industrial applications of our experiment, depleted

uranium would be used.”

In depleted uranium, the amount of the fissile

uranium – the isotope that splits apart – has been

reduced to well below natural levels. And the United

States has a lot of depleted uranium just waiting to be

put to use. In Bakac’s words, “It’s there, it’s available

and it’s safe.”

Heterogeneous vs. homogeneous

As simple as the photooxidation experiments are,

Bakac says she would still like to make the reactions

more efficient. In all of her reactions, the uranium,

oxygen and hydrocarbons get mixed together in a

homogeneous solution, and nothing is saved when

the reaction is over. “It would be ideal if we could

take the uranium out, separate it from the final

product and then reuse it,” she says.

Before her photooxidation experiment can move

from the lab to the real world, Bakac says she needs

additional funding to develop a heterogeneous system

that would make it possible to immobilize the uranium so that when the reaction was over, the catalyst

could be removed.

“I want to take a solid support and deposit the

uranium onto it so that when it’s put into solution the

uranium will still stick to that support – it won’t wash

into the solution,” she explains. “There would be a

layer of uranium on some inert surface, which would

need to have a lot of specific properties, such as

certain pore and channel sizes. The molecules would

have to be able to go in and come out and react with

each other. The support would also have to be thin

enough to let the light in.”

Bakac says there are some tremendous advantages to the heterogeneous system and the ability to

recover the uranium. “You have to be able to give

assurances to the community you work in that you are

not disposing of uranium in the ground water, soil or

anywhere else,” she says. “Also, recovering the

uranium would make the whole process more costefficient. If you can pull the catalyst out and reuse it,

that has to be a better way to go.”

Bakac says that she and her co-investigators,

Ames Lab physicist Marek Pruski and Iowa State

University chemical engineer Brent Shanks, haven’t

yet done any experiments on developing a heterogeneous system, but adds that they’re looking forward

to working on it as funds become available.

Benzene to phenol and toluene to

benzaldehyde

In the meantime, Bakac has had some noteworthy

success with the photooxidation of a number of

different hydrocarbons in homogeneous solutions.

She and Yun Mao, a former Ames Lab postdoctoral

fellow, were able to oxidize benzene to phenol, a

process that is industrially very significant because

phenol is an important starting chemical in the

manufacture of such products as resins, paints,

adhesives, phenolic plastics, synthetic fibers, herbiInquiry

2000

18

Andreja Bakac checks to see that the stream of oxygen is

sufficient and strong enough to help carry out the hydrocarbon oxidation reaction.
transport is a serious one. Also, it’s so unreactive that

it really doesn’t do anything other than burn. And

yet it would be an excellent source of methanol and

all of the chemicals derived from it. So this first

stage, the oxidation of methane to methanol, is an

extremely active area of research right now.”

Bakac says the reason they’ve been unable to

oxidize methane to methanol is because the solubility

of methane in water is very low, and the fundamental

research experiments are done

in homogeneous solution.

She notes that they might be

able to oxidize the methane in

a high-pressure reactor

equipped with the

uranium support

they plan to design.

“The higher the

pressure, the greater

the solubility of gas

in solvents,” she

explains. “Eventually

we would reach a

concentration where

the methane would

have to react. It’s

just that the reaction

is slow right now, and the high-pressure reactor

could speed it up by increasing the concentrations.”

Bakac says she’s excited about taking on the

methane to methanol challenge. She hopes to obtain

the necessary funding and get together with Pruski

and Shanks to start working on the project.

“The initial effort is just to get the right support

for the uranium and see if we can do any of the

reactions we’ve already done in homogeneous

solutions,” says an enthusiastic Bakac. “It would be a

major success if we could get anything to work in the

heterogeneous phase at this time. If we could, hey,

then anything is possible.” ❋

For more information:

Andreja Bakac, (515) 294-3544

bakac@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

cides and insecticides.

“Phenol is currently

produced in a very

cumbersome, multistep

reaction,” says Bakac. “Yet, we do it very nicely with

our uranium and light system, slightly modified for

this purpose.”

The benzene-to-phenol reaction works great,

according to Bakac. “It’s a very clean reaction, and

we get fantastic yield, which means light is being used

very efficiently.”

Another notable reaction that Bakac and her

colleagues have performed is the photooxidation of

the hydrocarbon toluene to benzaldehyde, a very

important intermediate in the chemical industry. “The

yield is not great,” she says, “but this may change in

the heterogeneous system.

“Excited uranium has been around for a very long

time, yet people haven’t tried to use it as a photocatalyst because some fundamental chemistry has not

been understood. And you can’t develop the application unless you understand the basics,” Bakac states.

Methane to methanol

Although she has photooxidized several different

kinds of hydrocarbons, Bakac is still hoping to

conquer the most difficult reaction. “That would be

the oxidation of methane to methanol,” she says.

“There are huge sources of methane available, but it

presents some problems. It’s a gas, so the problem of

Inquiry 19

2000

(left) Excited uranium is a

catalyst for the photochemical oxidation of

toluene to benzaldehyde.

(right) The light from an

analyzing beam induces

green luminescence of the

uranyl ions during a photooxidation experiment.
Robert Modler (left) and Andrew Thomas prepare an experiment to

investigate materials under simultaneous extreme conditions

of very low temperature, high pressure and high magnetic field.

new magnetic superconductors, Modler subjects them

to severe conditions in his lab of extreme environments. Observing how the materials behave in the

facility’s three-parameter space often reveals unique

properties that could prove beneficial to the development of new technologies.

“Chilling out”

To get a good look at the material he’s studying,

Modler places a sample in the dilution refrigerator,

which cools it until the material reaches its ground

state – the low-temperature, lowest-energy state at

which a material is almost completely free of excitations and vibrations.

The near absence of temperature disturbances in

the ground state makes it easier for scientists to learn

more about a material’s properties. In the ground

state, for example, there are fewer atomic vibrations to

interfere with the behavior of the conduction electrons

– you might even say that the material has “calmed

down,” which Modler says allows scientists to get a

very good picture of how the electrons move about in

the material. Alternatively, by increasing the temperature and taking the material out of the ground state,

they can see what excitations develop and how they

build up.

To achieve the ground state, the cryostat takes the

material under investigation through temperatures that

range from 300 K (room temperature) to 0.05 K (just

Some very complex materials exist on the borderline

between different states. Precariously perched, a little

nudge is all they need to push them over the edge

and drastically change their properties.

Studying the behavior of novel materials, especially those that sit on the brink of becoming something else, is Robert Modler’s specialty. What he finds

out about how they respond to changes in their

environment helps Ames Laboratory researchers better

understand these materials and determine their

suitability for possible future applications within fields

that include computer technology, communications,

medicine and the automotive industry.

One of few

Modler, an Ames Laboratory associate scientist,

investigates unusual materials under simultaneous

environmental extremes of very low temperature, high

pressure and high magnetic field. He does his

research in a new facility that he designed and set up

with Iowa State University graduate student Andrew

Thomas. The two researchers spent about a year

putting together the equipment for the facility, which

houses a helium three-helium four dilution cryostat, a

high-pressure cell and a high-field superconducting

solenoid to simultaneously create the three extreme

environments in one instrument.

“If you want to analyze and understand the

behavior of a new material, ideally you would like to

know as much as possible about how it reacts in this

three-dimensional parameter space,” says Modler.

“While quite a large number of researchers use one or

two of these parameters to investigate materials, only

a few really put very low temperature, high magnetic

field and high pressure together in one facility. I

would guess there are probably only five comparable

facilities in the world.”

As part of Ames Laboratory’s efforts to learn more

about complex materials such as exotic magnetic

molecules, quasicrystalline materials, semimetals and

By Saren Johnston

MEASURES

Inquiry

2000

20
Essential components of Ames Lab’s new combined extremes facility

are (left to right): high-vacuum can, heat shield, dilution cryostat

with attached high-pressure cell, and the superconducting solenoid.

Inquiry 21

2000

Just hanging out and hanging on

“The parameters of temperature, pressure and

magnetic field are used for materials research by many

scientists throughout the world. But putting all three

together in one experiment might ‘scare’ even a tough

material,” says Modler. He’s

intrigued most by those

materials that sit on the

borderline between different

states. These materials

could stay in limbo indefinitely if their environment

remained the same, but

Modler’s not about to let

that happen. His job is to

shake things up a bit, and

he does it very well.

“By applying just

enough pressure, magnetic

field or both to a ‘borderline’ material, we can push

it over the edge into a new

state and bring about drastic

changes in its physical

properties,” he says. “These

materials are unusually

complex; you might even

call them ‘adaptive’ to their

environments. By creating

the right conditions, you

can get a magnetic material

to become superconducting

or an insulated material to

become metal. To improve

our scientific understanding

of such materials, we look

very closely at how the changing states emerge from

each other and how they interact at the borderline.

That’s something interesting and not well studied to

this point. And through our new facility, we can

perform this research very comprehensively.” ❋❋

For more information:

Robert Modler, (515) 294-6353

modler@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

above absolute zero). Some intriguing “how cold is

cold” facts may provide insight on how chilly 0.05K

might be.

“On the Kelvin scale, absolute zero, or 0K, is

unreachable,” says Modler. “It would indicate the

total absence of heat. As a comparison, our background universe has

an average temperature of about 3K,

which stems from

cosmic microwave

background radiation.

In our lab, however,

we reach 0.05K on a

regular basis, which is

one-twentieth of a

Kelvin above absolute

zero. It’s an interesting thought that

temperatures this low

have never naturally

existed in our universe.”

Adding on

In addition to

cooling a material

dramatically, Modler

can further alter its

environment by

applying high pressure of up to 20,000

atmospheres. Subjecting a material to high

pressure alters the

distances between its

atoms and can strongly affect or even completely

change its properties.

“One atmosphere is equal to the air pressure

resting on the surface of the earth,” Modler explains.

“Pressure of 20,000 atmospheres is equivalent to about

300,000 pounds per square inch. It can be thought of

as approximately the weight of a Toyota Camry on the

tip of a medium-sized Phillips-head screwdriver.”

The third parameter of Modler’s lab of extreme

conditions is a powerful superconducting magnet for

magnetic fields up to 100,000 times that of the earth’s.

Just like high pressure, high magnetic field can cause

abrupt changes in a material. It can, for example,

change how magnetic moments are arranged in a

material, causing a different magnetic alignment – a

materials property perhaps most notably used in

computer hard disks.
Inquiry

2000

22

Before scientists develop

 ultrasonic techniques to view

fetuses in vivo, old wives’ tales

were as good a method as any for

determining a baby’s sex. Did the

mother eat peanuts after conception? Does the pillow on her bed

face north?

Just as nondestructive evaluation methods like ultrasound have

enabled doctors to safely gather

more information about a baby

before birth, they have made it

possible for other experts to

eliminate guesswork and understand more about their discipline.

Two Ames Laboratory metallurgists, Jim Foley and Dave Rehbein,

have merged the

fields of nondestructive evaluation

and powder

metallurgy, known

as P/M, and their

expertise. Though

not new, the two

areas combine to

put a new spin on

the study of

sintered metals.

Sintering is a solidstate process,

unlike melting, in

which compressed

metal powder is

heated to form a

solid mass. During

heating, the atoms

intermingle across

the powder contact

surfaces to “heal”

gaps, bonding the powders together.

Foley and Rehbein explored

options for applying ultrasonic

techniques to study P/M sintering

after Foley became leader of the

Lab’s Nondestructive Evaluation

group a few years ago.

“P/M has needed an in-process

sensor for a long time, but nothing

works very effectively. When Jim

became involved, we met to

discuss using the two fields to

improve on current techniques,”

Rehbein says.

Powdered metals are commonly used today in mass-produced parts made of low-alloy

steel, stainless steel, copper, brass

and low-strength aluminum. The

parts range from gears in automobile steering systems to mountings

for rearview mirrors.

But how do engineers know

when these bonds are at their

optimal strength? How, in the

arena of mass-produced parts, can

they guarantee that all of the gears

produced in a day have a particular strength without breaking them

apart to examine their properties?

Enter the electromagnetic

acoustic transducer, the tool Foley

and Rehbein are exploring for its

potential in P/M.

Much like ultrasound on a

fetus, EMAT enables them to

evaluate bonds in powdered

metals in real time, as they sinter

in a furnace. The tool’s primary

benefit is the elimination of wasted

time and materials required by the

current destructive examination of

prototype parts. The data the two

researchers can

acquire from

using EMAT could

turn guesswork

into formulas

engineers could

use to predict

processing

conditions when

mass producing

parts.

Currently, the

work of developing those formulas

can be inefficient

and time-consuming. Foley says

EMAT is a mechanism for smoothing out the rough

path of trial and

error.

“In an ideal

world, you wouldn’t need to do

any sintering experiments. You’d

have an equation and plug in

variables to determine the correct

processing conditions. But to get

to that stage, you need a method

for measuring sintering. That’s

what EMAT is,” he says. “In

sintering, the major factors are the

properties of the metal, time and

temperature. But as with any

science, we need to know how

these factors interact to create the

Researchers put a new

spin on the study of

sintered metals

by Danelle Baker-Miller

Jim Foley (left) and Dave Rehbein examine an electromagnetic

acoustic transducer, an in situ sensor that can measure the

sintering process of materials in real time.
been able to evaluate P/M parts this

way. This is very new science.

With EMAT, we can experiment and

determine when time and temperature are ideal to create powderedmetal parts strong enough to handle

the maximum loads. Eventually,

technology like EMAT could be

expanded for use in production,

even evaluating sintered parts on an

assembly line,” he says.

Though EMAT could eventually

see the interior of automotive

factories, it won’t lose its value as

an experimental tool. “The technique will still be important as an

experimental tool for new alloys. It

will always be used as a feedback

mechanism to be certain that a

metal’s properties are as good as

they should be,” Foley says. The

team plans to publish the sintering

models they develop. ❋

For more information:

Jim Foley, (515) 294-8252

foley@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences

DOE Laboratory Directed Research and

 Development funds

Inquiry 23

2000

strongest parts.”

EMAT has long been used to

detect internal flaws in metals.

David Hsu, a scientist at Iowa State

University’s Center for Nondestructive Evaluation, has used the

technique to study airplane wings

made of composite materials. To

make the paper and resin wings

electrically conductive, he covers

them with aluminum foil.

“A standard EMAT can be used

on anything that conducts electricity, but normally, the technology

won’t work under high temperatures because heat deteriorates the

strength of its permanent magnets,” Rehbein explains.

The commercial ultrasonic

tranducers Foley and Rehbein use

were custom-built by Ron Alers of

Sonic Sensors, a company in San

Luis Obispo, Calif., to tolerate

temperatures up to approximately

600 C (1,112 F). Unlike other

ultrasonic techniques that require a

couplant of water or jelly, EMAT is

noncontact and requires no

couplant. Their EMAT unit uses

two pairs of permanent magnets

and electrical coils, one on either

side of a pressed powdered-metal

part as it rests in a sintering

furnace. The magnetic and

electrical fields produce eddy

currents that create sound waves

inside the metal.

Rehbein likens the ultrasound

in EMAT to a microwave oven.

“The magnetic and electrical fields

come in combination from outside

the sample but produce sound

pulses inside the sample. Microwaves operate much the same

way, by creating heat inside the

food rather than by heating the

oven itself,” he says.

Inside the sample, sound

pulses respond to the strength of

the metal’s bonds by dying out

when bonds are weak or bouncing

back and forth in pinball fashion

when bonds are strong.

“The weaker the bonds, the

more difficult it is for sound waves

to propagate. The echo amplitude

is low and output in the receiving

end of the EMAT probe is weak,”

says Foley. “But when the bonds

become stronger, the wave output

more closely resembles the input.

We can see much higher peaks on

the monitor. In a 100-percent

dense piece of sintered metal, the

echo amplitude of the input wave

would be nearly

identical to the output

wave,” he explains.

On the way out,

the sound waves, in

combination

with the

magnetic field,

produce

electrical

voltage that is

measured with

an oscilloscope

and observed

on a computer

monitor.

Foley and

Rehbein are

confident they

are on the right

track – tests show a nearly 100

percent correlation between

measured output voltage and the

load-bearing capacity of aluminumcopper alloys containing different

percentages of silicon carbide after

the alloys were cooled and removed from the furnace.

“The data showed an absolutely wonderful correlation,” says

Rehbein. “I had a hard time

believing how well this technique

works. Whatever it is in a metal’s

atomic structure that is controlling

strength, it appears to also control

echo amplitude. We’re going to

work with Bruce Thompson,

director of ISU’s Center for Nondestructive Evaluation, to better

understand the connection.”

Foley underscores that the

EMAT-P/M combination is breaking

new ground. “No one else has

The graphic

illustrates the

strengthening of

bonds in a

powdered-metal

part as it sinters.

As bond strength

increases, so

does the measured echo

amplitude of the

transmitted

ultrasonic wave.
I

n the Midwest, as in most of

 the United States, crime laboratories

struggle with growing caseloads,

personnel shortages and a chronic

space crunch. Criminalists are

challenged with analyzing evidence

as quickly as possible, leaving them

little time to develop new equipment

and techniques that could enhance

the speed and accuracy of their

investigations.

That’s where Ames Laboratory

and Iowa State University’s Institute

for Physical Research and Technology

hope to come in. The two organizations are collaborating on a proposal

to establish a regional forensics

support and research facility at ISU.

The proposed Midwest Forensics

Resource Center would draw on the

expertise of faculty and staff members

at Ames Laboratory and IPRT, a network of multidisciplinary research

and technology-development centers

on the ISU campus. Ames Lab is part

of the IPRT network.

The forensics proposal received

$44,000 in seed funding from IPRT to

begin developing the partnerships

needed to launch the facility, and

organizers are working to identify

funding sources for the center.

David Baldwin, director of the

Lab’s Environmental and Protection

Sciences Program, says the forensics

center would serve three main

purposes. First, it would be an arena

for the development of new analytical

techniques and tools for forensic

investigators as well as providing an

outlet for technologies developed at

Ames Lab and other DOE laboratories.

Second, Iowa State students could

work at the facility to gain valuable

training prior to graduation, making

A Helping Hand for

Midwest Crime Labs By Susan Dieterle

them more attractive as potential

employees. Finally, the center would

serve as a regional training facility and

resource for local and federal agencies.

The regional aspect of the forensics

center will be crucial to its success,

Baldwin says. “We don’t want to be a

burden to any of the states in the

Midwest, especially Iowa,” he says.

“We don’t want to be a drain on

resources that might otherwise go to

the crime laboratories. The center

needs to be a regional laboratory that’s

funded nationally.”

Scientists at Ames Lab and IPRT

have already begun laying some of the

groundwork for the center through

forensics research projects for the FBI,

DOE and the Iowa Division of Criminal

Investigation.

To find out how the proposed

center could best serve crime laboratories, Baldwin and others involved in

efforts to establish the center met with

forensic investigators from eight

Midwestern states and four federal

agencies in May.

The crime-lab representatives gave

input on the types of research, services

and training that would be most helpful

to their facilities and suggested funding

sources for the proposed center.

Carl Bessman, a criminalist with the

Iowa Division of Criminal Investigation,

says the research assistance his crime

lab has already received from Ames

Lab and IPRT has proven valuable.

“Ultimately, applying good science to

the casework is our most important

responsibility,” he says. ❋

For more information:

David Baldwin, (515) 294-2069

dbaldwin@ameslab.gov

Inquiry

2000

24

Among the current

forensic projects at Ames

Lab and IPRT are restoring serial numbers (top

photo) that have been

removed from hard

metals (second photo);

better fingerprint detection methods (third

photo); and analyzing

bomb-blast fragments

(fourth photo).
(left) U.S. Department of Energy

Secretary Bill Richardson gets a

hands-on demonstration of magnetic

refrigeration during his visit to Ames

Laboratory.

(below) Ames Laboratory celebrates the 10th

anniversary of the DOE National Science Bowl

competition. Forty-seven Iowa high schools participated in the annual Ames Laboratory/Iowa State

University regional event.

(above) Gen. Eugene Habiger,

director of DOE s Office of

Security and Emergency

Operations (center, with white

name tag), tours Ames

Laboratory s machine shop.
Ames Laboratory

111 Technical and Administrative Services Facility

Ames, Iowa 50011-3020

(515) 294-9557

http://www.external.ameslab.gov

Inquiry

Ames Laboratory is a U.S. Department of Energy laboratory seeking

solutions to energy-related

problems through the exploration

of chemical, engineering, materials, mathematical and physical

sciences. Established in the 1940s

with the successful development

of the most efficient process to

produce high-purity uranium metal

for atomic energy, Ames Lab now

pursues much broader priorities

than the materials research that

has given the Lab international

credibility. Responding to issues

of national concern, Lab scientists

are actively involved in innovative

research, science education

programs, the development of

applied technologies and the quick

transfer of such technologies to

industry. Uniquely integrated

within a university environment,

the Lab stimulates creative thought

and encourages scientific discovery, providing solutions to complex

problems and educating

tomorrow’s scientific talent.

AMES LABORATORY

A U.S. Department of Energy

laboratory operated by

Iowa State University