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

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**MEMORANDUM OF UNDERSTANDING**

**FOR THE 2004 MESON TEST BEAM PROGRAM**

**T943**

**The Super B-Factory Monolithic Active Pixel Detector Prototype Group**

29 August, 2004

I.

INTRODUCTION 3

II\. PERSONNEL AND INSTITUTIONS: 6

III\. EXPERIMENTAL AREA, BEAMS AND SCHEDULE CONSIDERATIONS 7

IV\. RESPONSIBILITIES BY INSTITUTION - NON FERMILAB 8

V. RESPONSIBILITIES BY INSTITUTION - FERMILAB

5.1 Fermilab Beams Division 9

5.2 Fermilab Particle Physics Division 9

5.3 Fermilab Computing Physics Division 9

5.4 Fermilab ES&H Section 9

VI\. SPECIAL CONSIDERATIONS 10

SIGNATURES 11

APPENDIX I - Hazard Identification Checklist 12

# **I. INTRODUCTIOn:**

This proposal requests beam time at Fermilab during the 2004 Meson Test
Run to evaluate prototype Monolithic Active Pixel Sensors developed for
use in a Super-B Factory upgrade. In recent years, both the BaBar and
the Belle collaborations have taken advantage of the excellent
performances of their respective colliders, PEPII and KEKB. At both
sites, instantaneous luminosities on the order of 1.10^34^.cm^-2^.s^-1^
have been recorded.

With such high instantaneous luminosities, the innermost layers of the
Silicon Vertex Detectors reach occupancies close to the 10% level. From
the perspective of a Super-B Factory upgrade, backgrounds will increase
by a factor of at least 20. Projected occupancies in the innermost
layers of the tracking detectors will not be manageable unless a drastic
technology change is pursued. Since conventional Silicon Strip detectors
are unable to cope with the projected occupancy, we propose to use a
detector of a finer granularity. Pixel detectors come naturally to mind,
though hybrid pixel detectors are not well suited to the relatively low
energy B Factory environment, as they introduce too much material near
the interaction point. Monolithic Active Pixel Sensors (MAPS), on the
other hand, are much better matched to our needs, as they provide fine
granularity and can also be thinned.

The University of Hawaii has developed two prototypes denoted the
Continuous Acquisition Pixel prototypes, CAP1 and CAP2. Both are based
on the TSMC 0.35μm process that is a standard CMOS process (good
reliability, high volumes for low cost, etc.). The basic concept of the
CAP is quite simple. As a first exercise, and to gain experience with
these devices, we took the standard 3-transistor cell, which is shown in
Figure 1, and built an infrastructure around it to read out as fast as
possible.

![](media/image2.wmf){width="6.720138888888889in"
height="1.8041666666666667in"}

Figure 1: The basic 3-transistor pixel cell. M1 is the reset, M2 senses
the gate voltage shift due to collected charge, and M3 is the output
select.

An electrode is tied to the gate of transistor M2. When held at a
positive potential with respect to the surrounding well and substrate,
electrons from deposited ionization are collected on this electrode. As
this eventually causes the collection potential to be lost due to
negative charging, a periodic reset must be applied to transistor M1 to
restore the collection potential. A further transistor, M3, provides the
mechanism by which individual pixels may be selectively accessed for
readout. In order to gain experience with this architecture, two
variations of this basic theme were designed. CAP1 consists only of the
above-mentioned 3-transistor circuit and an array of logic and analog
multiplexors to pass the analog values out as promptly as possible. For
the design of CAP2, 8 storage buffers were implemented in each pixel
cell, as well as a mechanism to loop through the storage buffers and
select the appropriate one (for read and write). Hence in CAP2, data can
be recorded in each pixel for the trigger latency time, and does not
need to be transferred out of the CAP for verification: therefore only
the relevant data frames -corresponding to a trigger- need to be
transferred. With its internal buffering, a CAP2-like structure fits the
need of high live-time and short integration time.

CAP1 and CAP2 are both made of an array of 6336 pixels. Each pixel size
is 22.5μm^2^. A previous test beam has been performed in the summer 2004
and the operational capability of CAP1 has been demonstrated. During
this test beam, an upper limit on the intrinsic resolution of 11μm was
measured. GEANT simulations show the large separation between detectors
and excess material in the detector supports limited the resolution that
could be obtained. Subsequently, a new compact set-up with reduced
material has been developed with guidance from simulation and we expect
to be able to probe the intrinsic resolution of these devices. Also,
operation of CAP2 was achieved in the lab and first testing of CAP2
looks very promising. We would like now to prove operation of this
second CAP prototype in a beam test environment. Finally, MAPS
radiation-hardness has still to be assessed. Initial testing looks very
promising, as can be seen in Figure 2, which compares a measurement done
by *Eid et al.* \[IEEE Trans. Nucl. Sci., Vol. 48, No. 6, pp.
1796-1806\] and our own experience with CAP1.

![](media/image3.wmf){width="5.572222222222222in"
height="3.717361111111111in"}

Figure 2: Leakage current in pA.cm^-2^ as a function of radiation in
Mrad, and effect of annealing on the CAP1 detector.

As can be seen in this figure, the leakage current for a prototype
irradiated to a 2 Mrad dose decreased by 2 orders of magnitude after
proper annealing. Annealing of detectors irradiated at 3 Mrad and 20
Mrad is in progress. These results are encouraging but we must now
demonstrate operation of these heavily irradiated detectors in a beam
test context.

This is a memorandum of understanding between the Fermi National
Accelerator Laboratory and the Hawaii, Tsukuba, KEK and INP Krakow high
energy experimenters who have committed to participate in beam tests to
be carried out during the 2004 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
that will reflect such required adjustments.

# **II. PERSONNEL AND INSTITUTIONS:**

Physicist in charge of beam tests: Gary S. Varner, University of Hawaii

Fermilab liaison: Erik Ramberg

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

2.1 University of Hawaii: M. Barbero, T. Browder, F. Fang, S. Olsen, K.
Trabelsi, G. Varner

Other commitments:

> Belle: M. Barbero, T. Browder, F. Fang, S. Olsen, K. Trabelsi, G.
> Varner
>
> ANITA: G. Varner

2.2 KEK: M. Hazumi, T. Tsuboyama

Other commitments:

Belle: M. Hazumi, T. Tsuboyama

# 2.3 inp Krakow: A. Bozek, H. Palka

Other commitments:

Belle: A. Bozek, H. Palka

2.4 Tsukuba University: S. Stanic.

Other commitments:

Belle: S. Stanic

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

3.1 LOCATION

3.1.1 The experiment is to take place in the MTEST beam line. We are
flexible in the precise location of our sensors and readout electronics,
but it is likely that we will use the area designated as MT6-B2.

3.1.2 Additional work space will be needed at a location of convenience,
equivalent to at most two 6'x3' tables. This space will be used for
computing and general work space.

3.2 BEAM

3.2.1 The tests will use slow resonantly-extracted, Main Injector proton
beam focused onto the MTest target. We are flexible in the composition
of the beam providing momentum is well above 1GeV/c.

3.2.2 Intensity: Variable, in the range of 1-10 KHz in an area of 1
square cm. Self triggering permits efficient operation at lower rates,
if necessary.

3.2.3 We can make good use of any reasonable operating mode planned for
MTEST.

3.3 SETUP

3.3.1 At most half a day of access to the experimental area will be
needed to set up the pixel test stand, and includes not only survey of
the pixel telescope planes and mechanical apparatus, but also the cable
work.

3.3.2 At least one additional shift will be needed to install and debug
the DAQ and logic associated with the trigger. This will require only
sporadic access.

-   Cabling to the counting room is minimal and consists primarily of
    the 8 Cat-5 ethernet cable connections between the front-end readout
    boards and out back-end compact-PCI readout crate. These cable
    provide both power and signal transfer.

-   Cabling is simplified by obviating the need for separate High
    Voltage and DC power cabling

3.3.3 We will need a static, adjustable-height stage to locate the
detector assembly in the beamline.

3.4 SCHEDULE

> We are requesting a half day of setup time and a subsequent shift of
> DAQ commissioning (sufficient from previous experience) followed by
> the rest of a week of regular data taking. Each run will consist of a
> few hours of event logging, and we will take data in a couple of
> different configurations with normal and severely irradiated 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.

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

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

4.1 All equipment and DAQ will be supplied by the U. Hawaii group. This
includes:

4.1.1 MAPS samples under test(\$0.5k each) \[\$16k\]

4.1.2 layer mounts (1+1 spare), plus mini trigger scintillators/PMTs
\[\$4k\]

4.1.3 cPCI Crate, with embedded CPU \[\$4.5k\]

4.1.4 2 laptop PC's, monitors, Ethernet and hub \[ \$5k\]

4.1.5 CD drives for data archiving \[ \$0.5k\]

4.1.6 Soldering iron \[ \$1k\]

4.1.7 CAT-5 cables, voltmeters, tools, toolbox \[ \$1k\]

Total existing items \[\$32K\]

**V. RESPONSIBILITIES BY INSTITUTION - FERMILAB**

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

## 5.1 Fermilab Accelerator Division:

5.1.1 Use of MTest beam.

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

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

5.1.4 Reasonable access to our equipment in the test beam.

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

5.1.6 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.

5.1.7 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.

## 5.2 Fermilab Particle Physics Division 

## 

5.2.1 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.

5.3 Fermilab Computing Division

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

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

5.3.3 No PREP equipment will be needed for this experiment.

5.4 Fermilab ES&H Section

5.4.1 Assistance with safety reviews.

# 

# 

# 

#  

# **VI. SPECIAL CONSIDERATIONS**

6.1 The responsibilities of the CAP Pixel 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 CAP Pixel 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 CAP Pixel Detector Research 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 and has the relevant radiation and controlled
access training.

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. The CAP Pixel Detector Research
Group will ensure that any irradiated devices will be monitored for
activation and that any experimenter handling irradiated materials will
have the proper training.

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

6.6 The CAP Pixel 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 CAP Pixel 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 CAP Pixel 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, tapes, etc.

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

**SIGNATURES:**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ / /
2004

Gary Varner, University of Hawaii

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2004

Jim Strait, Particle Physics Division

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2004

Roger Dixon, Accelerator Division

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2004

Victoria White, Computing Division

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ / 2004

William Griffing, ES&H Section

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ /2004

Hugh Montgomery, Associate Director, Fermilab

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
/ /2004

Steven Holmes, Associate Director, Fermilab

**APPENDIX I - 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></td>
<td colspan="3">high voltage</td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3">Bubble chamber</td>
<td></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></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></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></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></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>