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     ![](media/image1.wmf){width="0.44166666666666665in"                    
     height="0.41597222222222224in"} **Fermilab Directorate**               

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**MEMORANDUM OF UNDERSTANDING**

**FOR THE 2002-2003 MESON TEST BEAM PROGRAM**

**T932**

**The Diamond Detector Research Group**

January 12, 2002

INTRODUCTION 3

I. PERSONNEL AND INSTITUTIONS: 5

II\. EXPERIMENTAL AREA, BEAMS AND SCHEDULE CONSIDERATIONS 5

III\. RESPONSIBILITIES BY INSTITUTION - NON FERMILAB 6

IV\. RESPONSIBILITIES BY INSTITUTION - FERMILAB 6

4.1 Fermilab Beams Division 6

4.2 Fermilab Particle Physics Division 7

4.3 Fermilab Computing Physics Division 7

4.4 Fermilab ES&H Section 7

V. Summary of Costs 7

VI\. SPECIAL CONSIDERATIONS 8

SIGNATURES 9

appendix i - cvd diamond properties 10

Appendix II - prep equipment pool needs 11

APPENDIX III - Hazard Identification Checklist 12

INTRODUCTION

This proposal requests beam time at Fermilab during the 2003 Meson Test
Run to test Chemical Vapor Deposition (CVD) diamond pixel detectors. Our
research in this area began nearly a decade ago when we realized that
CVD diamond is a promising, radiation-hard alternative to silicon. Our
work has been funded by DOE, TNRLC, and NSF; we are currently funded by
an NSF MRI grant. Below we detail what we expect to accomplish in beam
tests of diamond detectors as well as what resources are required.

In Appendix I, we summarize the properties of diamond and, for
comparison, those of silicon. The most distinctive feature of diamond is
its large band gap, 5.5 eV. This large band gap along with the
associated large cohesive energy are responsible for much of the
radiation hardness of diamond. The large band gap also makes diamond an
excellent electrical insulator. As a result, a large electric field can
be applied without producing significant leakage current. Thus, there is
no need for a reverse biased *pn*-junction and the diamond detector
functions much like a \`\`solid-state\'\' ionization chamber. Diamond
has two additional properties that are favorable compared to silicon.
Its smaller dielectric constant yields a smaller detector capacitance
and, thereby, better noise performance of the associated front-end
electronics. In addition, even though diamond is an electrical
insulator, it is an excellent thermal conductor with a thermal
conductivity exceeding that of copper by a factor of five. A common
problem with large strip detector systems is the management of the
thermal load generated by the large number of electronic channels used
in the detector readout. The handling of this thermal load would be
simplified if the detectors were constructed from diamond.

Diamond appears ideal in many respects but it does have a limitation:
the large band gap which produces many of its outstanding properties
limits the signal size to at most half that of silicon for a given
detector thickness in radiation lengths. This may be partially
compensated by lower front-end electronic noise due to diamond\'s nearly
non-existent leakage current and, for strip detectors, diamond\'s lower
capacitive load.

In the figure below, we show the basic principle behind the use of
diamond as a charged particle detector. Several hundred volts (\~1V/μm)
is applied across a layer of diamond a few hundred microns thick.

![](media/image2.wmf){width="3.5180555555555557in"
height="1.9069444444444446in"}

When a charged particle traverses the diamond, atoms in the crystal
lattice sites are ionized, promoting electrons into the conduction band
and leaving holes in the valence band. On average, 3,600 electron-hole
pairs are created per 100 μm of diamond traversed by a minimum ionizing
track. These charges drift across the diamond in response to the applied
electric field producing a signal that can be measured.

An interesting feature of diamond sensors is the improvement in charge
collection with exposure to ionizing radiation for exposures up to about
1 kRad. This ''pump-up'' effect is due to an increase of carrier
lifetime caused by passivation of deep traps. Because diamond has such a
large band gap there may exist traps more than 1 eV from the valence or
conduction bands. Exposure to radiation fills these traps with electrons
(holes) produced by the radiation. If the traps are far enough from the
conduction (valence) bands, the rate of thermal ionization of these
traps will be slow and they will remain passivated for long times. We
have found that diamonds kept in the dark remained ''pumped'' for many
months. Exposure to light of the energy of the traps rapidly ionizes the
traps and ''depumps'' the diamond.

This is a memorandum of understanding between the Fermi National
Accelerator Laboratory and Rutgers and Purdue University High Energy
experimenters who have committed to participate in beam tests to be
carried out during the 2002-2003 MTBF program. The memorandum is
intended solely for the purpose of providing a budget estimate and a
work allocation for Fermilab, the funding agencies and the participating
institutions. It reflects an arrangement that currently is satisfactory
to the parties; however, it is recognized and anticipated that changing
circumstances of the evolving research program will necessitate
revisions. The parties agree to negotiate amendments to this memorandum
which will reflect such required adjustments.

# **I. PERSONNEL AND INSTITUTIONS:**

Physicist in charge of beam tests: Steven Worm, Rutgers Univ.

Fermilab liaison: Erik Ramberg

The group members at present and others interested in the testbeam are:

1.1 Rutgers University: J. Doroshenko, T. Koeth, L. Parera, S.
Schnetzer, R. Stone, S. Worm

Other commitments:

> CDF: S. Worm
>
> CMS: J. Doroshenko, L. Parera, S. Schnetzer, R. Stone, S. Worm
>
> HiRes: L. Parera, S. Schnetzer

1.2 Purdue University: D. Bortoletto, I. Shipsey, G. Bolla, J. Lee, K.
Arndt, A. Roy, S. Son.

Other commitments:

> CDF and CMS: D. Bortoletto, G. Bolla, A. Roy

CLEO and CMS: I. Shipsey, J. Lee, K. Arndt

# 

# **II. EXPERIMENTAL AREA, BEAMS AND SCHEDULE CONSIDERATIONS**

1.  LOCATION

    1.  The experiment is to take place in the MTEST beam line and
        located in the area designated MT6-A2. In addition, the alcove
        control room to the east of the MTEST line will be used to house
        electronics (up to two 19" racks of electronics)

    2.  Additional work space will be needed in this control room,
        equivalent to at most two 6'x3' tables. This space will be used
        for computing and general work space.

2.  BEAM

    2.  The tests will use slow resonantly-extracted, Main Injector
        proton beam focused onto the MTest target. The tests require a
        beam of untagged, charged particles of energy approximately 80
        GeV.

    3.  Intensity: Variable, in the range of 1-10 KHz in an area of 1
        square cm. With the current beam line design this is expected to
        require up to 2 x 10^10^ primary protons per second.

    4.  We can make good use of the planned initial beam to MTEST.
        Currently this is envisioned to be a 1 sec spill per 60 sec
        supercycle. We are modifying our DAQ to take advantage of this
        scenario.

    5.  We anticipate some parasitic running during the test beams
        outlined in T927 (BTeV pixel test beam, located at MT6-A1). We
        would like to be informed of any accesses.

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2.  SETUP

    2.  At least one full day of access to the experimental area will be
        needed to set up the pixel test stand. This includes not only
        the silicon telescope planes and mechanical apparatus, but also
        the cable work.

    3.  At least one additional day will be needed to install and debug
        the DAQ and NIM logic associated with the trigger. This would
        require only sporadic access.

    4.  Cabling to the counting room is significant. We have allowed one
        day of setup time. An outline of our cable needs between
        counting house and MT6-A2 include:

-   Strip sensors (3 cond. for power, 20 cond. ribbon, 6 RG58 BNC coax)

-   Pixel sensors (3 cond. for power, 60 cond. ribbon, 16 RG58 BNC coax)

-   Trigger scintillators (5 RG59 SHV for voltage, 38 RG58 BNC coax)

-   Power, Ethernet, DAQ interconnection cables (in counting house)

3.  SCHEDULE

    2.  We are requesting a few days of setup time followed by three
        weeks of regular data taking. Each run will consist of a few
        hours of measurements, and we will take data with about 12
        devices and possibly at several angles of incidence to the beam
        for each. Upon changing to a new device under test or a new
        angle of incidence, access to the experimental area will be
        needed.

# **III. RESPONSIBILITIES BY INSTITUTION - NON FERMILAB**

> (\[\] denotes replacement cost of existing hardware.)

1.  Diamond samples under test (\$1k each) \[\$12k\]

2.  Mechanical translation stage, stepper motors, computer control
    \[\$10k\]

3.  (All equipment and DAQ will be supplied by the Rutgers University
    group.)

    1.  Repeater card box, repeater boards, (Vienna) ADC \[\$5k\]

    2.  VME Crate w/ 5, 2V supplies (if item 2 in Appendix I is
        unavailable) \[ 3\]

    3.  Silicon telescope mechanical assembly \[ 2\]

    4.  Silicon telescope detector planes and holders \[15\]

    5.  Digital scope \[10\]

    6.  Keithley 237 Voltage/Current Source \[ 8\]

    7.  Pulse generator w/ adj rate knob \[ 2\]

    8.  Comp. control attenuator \[ 1\]

    9.  2 10V supplies 10A \[ 1\]

    10. 2 PC's, monitors, Ethernet and hub \[ 3\]

    11. 2 DLT drives and tapes \[ 2\]

    12. Soldering iron \[ 1\]

    13. Asst. lemo cables, voltmeters, tools, toolbox \[ 1\]

    14. 60 150' BNC, SHV, lemo, and ribbon cables \[ 2\]

    15. Remote positioning system (manipulators, encoders) \[ 3\]

    16. CCD camera for monitoring \[ 1\]

Total existing items \[\$82K\]

**IV. RESPONSIBILITIES BY INSTITUTION - FERMILAB**

(\[\] Denotes replacement cost of existing hardware.)

## 4.1 Fermilab Beams Division:

1.  Use of MTest beam.

2.  Maintenance of all existing standard beam line elements (SWICs, loss
    monitors, etc) instrumentation, controls, clock distribution, and
    power supplies.

3.  A scaler or beam counter signal should be made available in the
    counting house.

4.  Reasonable access to our equipment in the test beam.

5.  The test beam energy and beam line elements will be under the
    control of the BD Operations Department Main Control Room (MCR).

6.  Position and focus of the beam on the experimental devices under
    test will be under control of MCR. Control of secondary devices that
    provide these functions may be delegated to the experimenters as
    long as it does not violate the Shielding Assessment or provide
    potential for significant equipment damage.

7.  The integrated effect of running this and other SY120 beams will not
    reduce the antiproton stacking rate by more than 5% globally, with
    the details of scheduling to be worked out between the experimenters
    and the Office of Program Planning.

4.1.S Summary of Beam Division costs:

Type of Funds Equipment Operating Personnel

(person-weeks)

Total new items \$0.0K \$0K 0.0

## 4.2 Fermilab Particle Physics Division 

## Adequate lighting for the MT6-A2 area is requested, as there is currently only indirect lighting from upstream. The estimated cost and time are given below.

4.2.2 Cooling water (or a chiller) and dry nitrogen (for electronics)
should be provided.

4.2.3 The test-beam efforts in this MOU will make use of the Meson Test
Beam Facility. Requirements for the beam and user facilities are given
in Section 2. The Fermilab Particle Physics Division will be responsible
for coordinating overall activities in the MTest beam-line, including
use of the user beam-line controls, readout of the beam-line detectors,
and MTest gateway computer.

4.2.S Summary of Particle Physics Division costs:

Type of Funds Equipment Operating Personnel

(person-weeks)

Total new items \$0.2K \$0K 0.2

4.3 Fermilab Computing Division

1.  Ethernet and printers should be available in the counting house.

2.  Connection to beams control console and remote logging (ACNET)
    should be made available in the counting house.

3.  See Appendix II for summary of PREP equipment pool needs.

4.4 Fermilab ES&H Section

1.  Assistance with safety reviews.

2.  Loan of radioactive source (preferably Sr^90^, 5mCi) for the
    duration of the test beam.

# 

# **V. Summary of Costs**

**Source of Funds \[\$K\] Equipment Operating Personnel**

(person-weeks)

Particle Physics Division \$0.2K \$0K 0.2

Beams Division 0 0 0

Computing Division 0 0 0

Totals Fermilab \$0.2K 0 0.2

Totals Non-Fermilab \[\$82K\]

# 

# **VI. SPECIAL CONSIDERATIONS**

6.1 The responsibilities of the Diamond Detector Research Group
Spokesperson and procedures to be followed by experimenters are found in
the Fermilab publication \"Procedures for Experimenters\" (PFX). The
Physicist in charge agrees to those responsibilities and to follow the
described procedures.

6.2 To carry out the experiment a number of Environmental, Safety and
Health (ES&H) reviews are necessary. This includes creating a Partial
Operational Readiness Clearance document in conjunction with the
standing Particle Physics Division committee. The Diamond Detector
Research Group Spokesperson will follow those procedures in a timely
manner, as well as any other requirements put forth by the division's
safety officer.

6.3 The Diamond Detector Test Beam Spokesperson will ensure that at
least one person is present at the Meson Test Beam Facility whenever
beam is delivered and that this person is knowledgeable about the
experiment's hazards.

6.4 All regulations concerning radioactive sources will be followed. No
radioactive sources will be carried onto the site or moved without the
approval of the Fermilab ES&H section.

6.5 All items in the Fermilab Policy on Computing will be followed by
experimenters.

6.6 The Diamond Detector Research Group Spokesperson will undertake to
ensure that no PREP and computing equipment be transferred from the
experiment to another use except with the approval of and through the
mechanism provided by the Computing Division management. They also
undertake to ensure that no modifications of PREP equipment take place
without the knowledge and consent of the Computing Division management.

6.7 Each institution will be responsible for maintaining and repairing
both the electronics and the computing hardware supplied by them for the
experiment. Any items for which the experiment requests that Fermilab
performs maintenance and repair should appear explicitly in this
agreement.

6.8 If the experiment brings to Fermilab on-line data acquisition or
data communications equipment to be integrated with Fermilab owned
equipment, early consultation with the Computing Division is advised.

6.9 At the completion of the experiment:

6.9.1 The Diamond Detector Research Group Spokesperson is responsible
for the return of all PREP equipment, Computing equipment and non-PREP
data acquisition electronics. If the return is not completed after a
period of one year after the end of running the Diamond Detector
Research Group Spokesperson will be required to furnish, in writing, an
explanation for any non-return.

6.9.2 The experimenters agree to remove their experimental equipment as
the Laboratory requests them to. They agree to remove it expeditiously
and in compliance with all ES&H requirements, including those related to
transportation. All the expenses and personnel for the removal will be
borne by the experimenters.

6.9.3 The experimenters will assist the Fermilab Divisions and Sections
with the disposition of any articles left in the offices they occupied,
including computer printout and magnetic tapes.

6.9.4 An experimenter will report on the test beam effort at a Fermilab
All Experimenters Meeting.

**SIGNATURES:**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ / /
2003

Steven Worm, Rutgers University

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2003

John Cooper, Particle Physics Division

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2003

Roger Dixon, Beams Division

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2003

Victoria White, Computing Division

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2003

William Griffing, ES&H Section

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ /2003

Hugh Montgomery, Associate Director, Fermilab

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ /2003

Steven Holmes, Associate Director, Fermilab

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2003

Michael Witherell, Director, Fermilab

#  **Appendix I -- diamond DETECTOR BEAM TEST -- Diamond properties**

  --------------------------------------- ---------------- ---------------
  **Property**                            **Diamond**      **Silicon**

  Band Gap \[eV\]                         5.5              1.12

  Breakdown field \[V/cm\]                10^7^            3x10^5^

  Resistivity \[Ω cm\]                    \>10^11^         2.3x10^5^

  Intrinsic Carrier Density \[cm^-3^\]    \<10^3^          1.5x10^10^

  Electron Mobility \[cm^2^V^-1^s^-1^\]   1800             1350

  Hole Mobility \[cm^2^V^-1^s^-1^\]       1200             480

  Saturation Velocity \[km/s\]            220              82

  Mass Density \[g cm^-3^\]               3.5              2.33

  Atomic Charge                           6                14

  Dielectric Constant                     5.7              11.9

  Thermal Expansion Coefficient \[K^-1^\] 0.8x10^-6^       2.6x10^-6^

  Thermal Conductivity \[W m^-1^ K^-1^\]  1000-2000        150

  Cohesive Energy \[eV/atom\]             7.37             4.63

  Energy to create e-h pair \[eV\]        13               3.6

  Radiation Length \[cm\]                 12.0             9.4

  Spec. Ionization Loss \[MeV/cm\]        4.69             3.21

  Ave. Signal Created/100 μm \[e\]        3600             8900

  Ave. Signal Created/0.1% X~0~ \[e\]     4500             8400
  --------------------------------------- ---------------- ---------------

Table 1: The physical properties of diamond and silicon at 293K
{Zhao91}.

#  **Appendix II -- Diamond Detector beam test -- Equipment pool needs**

Equipment Pool items needed for Fermilab test beam, needed on the first
day of setup:

[Quantity]{.underline} [Description]{.underline}

4 Nim crates, with cooling fans

1 VME crate and power supply with CERN modified JAUX: -5,-2 Volt

1 NIM 4CH 3/8KV 3/1mA HV POWer CAEN N470 or equivalent

5 NIM Octal descriminators Lecroy 623

4 NIM logic fan in/out Lecroy 429a

2 Quad Scaler and Preset Counter CAEN N145 or equivalent

6 NIM Dual Timing unit CAEN N93B/2255B

4 NIM Tri- coincidence logic Lecroy 465

3 NIM quad-coin. logic Lecroy 622

1 TTL  Nim level adapter Lecroy 688AL

2 Caen N570 dual +HV supplies or equivalent

1 pulse gen. fast risetime ( \<5ns ) +- 20v

1 analogue or digital oscilliscope

2 adjustable (\~7Volt @ \>= 2 amp) DC low noise supplies for Si strips

2 adjustable (\~8Volt @ \>= 2 amp) DC low noise supplies (Vienna pixel)

**APPENDIX III - Hazard Identification Checklist**

Items for which there is anticipated need have been checked

<table style="width:100%;">
<colgroup>
<col style="width: 4%" />
<col style="width: 5%" />
<col style="width: 2%" />
<col style="width: 20%" />
<col style="width: 4%" />
<col style="width: 5%" />
<col style="width: 5%" />
<col style="width: 17%" />
<col style="width: 5%" />
<col style="width: 28%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="4"><strong>Cryogenics</strong></td>
<td colspan="4"><strong>Electrical Equipment</strong></td>
<td colspan="2"><p><strong>Hazardous/Toxic</strong></p>
<p><strong>Materials</strong></p></td>
</tr>
<tr class="even">
<td></td>
<td colspan="3">Beam line magnets</td>
<td></td>
<td colspan="3">Cryo/Electrical devices</td>
<td></td>
<td>List hazardous/toxic materials</td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3">Analysis magnets</td>
<td></td>
<td colspan="3">capacitor banks</td>
<td></td>
<td>planned for use in a beam line or experimental enclosure:</td>
</tr>
<tr class="even">
<td></td>
<td colspan="3">Target</td>
<td><strong>X</strong></td>
<td colspan="3">high voltage</td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3">Bubble chamber</td>
<td><strong>X</strong></td>
<td colspan="3">exposed equipment over 50 V</td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td colspan="4"><strong>Pressure Vessels</strong></td>
<td colspan="4"><strong>Flammable Gases or Liquids</strong></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td>inside diameter</td>
<td colspan="2">Type:</td>
<td colspan="2"></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td>operating pressure</td>
<td colspan="2">Flow rate:</td>
<td colspan="2"></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td>window material</td>
<td colspan="2">Capacity:</td>
<td colspan="2"></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td>window thickness</td>
<td colspan="4"><strong>Radioactive Sources</strong></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="4"><strong>Vacuum Vessels</strong></td>
<td></td>
<td colspan="3">permanent installation</td>
<td colspan="2"><strong>Target Materials</strong></td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td>inside diameter</td>
<td><strong>X</strong></td>
<td colspan="3">temporary use</td>
<td></td>
<td>Beryllium (Be)</td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td>operating pressure</td>
<td colspan="3">Type:</td>
<td><strong>Sr90</strong></td>
<td></td>
<td>Lithium (Li)</td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td>window material</td>
<td colspan="3">Strength:</td>
<td><strong>5 mCi</strong></td>
<td></td>
<td>Mercury (Hg)</td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td>window thickness</td>
<td colspan="4"><strong>Hazardous Chemicals</strong></td>
<td></td>
<td>Lead (Pb)</td>
</tr>
<tr class="even">
<td colspan="4"><strong>Lasers</strong></td>
<td></td>
<td colspan="3">Cyanide plating materials</td>
<td></td>
<td>Tungsten (W)</td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3">Permanent installation</td>
<td></td>
<td colspan="3">Scintillation Oil</td>
<td></td>
<td>Uranium (U)</td>
</tr>
<tr class="even">
<td></td>
<td colspan="3">Temporary installation</td>
<td></td>
<td colspan="3">PCBs</td>
<td><strong>X</strong></td>
<td>Other : <strong>Si, C (diamond)</strong></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3">Calibration</td>
<td></td>
<td colspan="3">Methane</td>
<td colspan="2"><strong>Mechanical Structures</strong></td>
</tr>
<tr class="even">
<td></td>
<td colspan="3">Alignment</td>
<td></td>
<td colspan="3">TMAE</td>
<td></td>
<td>Lifting devices</td>
</tr>
<tr class="odd">
<td colspan="2">type:</td>
<td colspan="2"></td>
<td></td>
<td colspan="3">TEA</td>
<td><strong>X</strong></td>
<td>Motion controllers</td>
</tr>
<tr class="even">
<td colspan="2">Wattage:</td>
<td colspan="2"></td>
<td></td>
<td colspan="3">photographic developers</td>
<td></td>
<td>scaffolding/elevated platforms</td>
</tr>
<tr class="odd">
<td colspan="2">class:</td>
<td colspan="2"></td>
<td></td>
<td colspan="3">Other: Activated Water?</td>
<td></td>
<td>Others</td>
</tr>
</tbody>
</table>