ilc prototype muon scintillation counter tests

March 12, 2006 R. Abrams LCWS06 Bangalore

1

ILC Prototype Muon Scintillation Counter Tests

Robert Abrams

Indiana University


2

Introduction• Collaboration: FNAL, IU, UND, WSU, (UCDavis)• Testing program was first reported at Stanford, LCWS05,

using a small pre-prototype.• At Snowmass, ALCPG05, results of source tests and

cosmic ray tests of 2 quarter-sized prototype modules were reported.

• At this time, there are 2 more prototype modules, with dual readout. – Results of pulse shape studies will be presented.– The set of 4 modules has been installed in the FNAL

test beam, and preliminary results will be presented.• Future plans will be presented.


3

Test Setup as reported at Snowmass

Proto #1 with MAPMT,Proto #2 with Single PMT

Proto #1 with Single PMT.Cosmic ray trigger paddles

Single Anode PMT: Hamamatsu E934-0164-element MAPMT: Hamamatsu H7546B


4

Prototype Muon Detectors(Snowmass)

• Module dimensions 1.25m x 2.5m• Constructed at University of Notre Dame • 64 scintillator strips per module• 2 modules built, +/- 45 degrees• Strips #22-43 same length across entire width• Wavelength shifter fibers in grooves spliced to

clear fibers that run from scintillator to cookie.• 9 sets of LED-driven fiber bundles illuminate

ends of all strips for monitoring• Proto #S2 has PIN photodiodes to monitor LEDs


5

Single Readout Module Layout

2243 21

1

44

64

224321

1

44

64

Clear fibers to cookie (Readout Side)


MAPMT

MAPMT

Cookie

Cookie

Prototype #S1

Prototype #S2


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Prototype #D2

Prototype #D12243 21

1

44

64


MAPMT Cookie

Clear fibers to cookie (2nd Readout Side)

(a)

(b)

224321

1

44

64


MAPMT Cookie

Clear fibers to cookie (2nd Readout Side)

(b)

(a)

Layout of New Dual Readout Modules


7

MAPMT Connections (Snowmass Configuration)

External cabling Interior of connector box


8

New Connector Board and Box

MAPMT base soldered to boardInternal wires in board (4 layers).4 connectors, each has 16 signals

Internal jumper cables to externalMultipin connectors

New cookie design allows for magnetic shielding and better light seal at MAPMT


9

Study of Pulse Shapes

• Investigated pulse shapes of signals from detectors to determine if time-over threshold could be used for signal size


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Sample Traces from Cosmic Ray Triggers

Cosmic Ray Trigger

-0.09

-0.08

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0

0.01

-5.00E-08

-3.00E-08

-1.00E-08 1.00E-08 3.00E-08 5.00E-08

CH1

CH2

File TEK00031

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0

0.01

-6.00E-08

-4.00E-08

-2.00E-08

0.00E+00

2.00E-08

4.00E-08

CH1

CH2

File TEK00032

-1.20E-01

-1.00E-01

-8.00E-02

-6.00E-02

-4.00E-02

-2.00E-02

0.00E+00

2.00E-02

-6.00E-08

-4.00E-08

-2.00E-08

0.00E+00

2.00E-

08

4.00E-

08

6.00E-

08

CH1

CH2

CH1 is MAPMT on Counter S2, Strip #22 (Blue trace)CH2 is SAPMT (Single Anode PMT) on Counter S1 (Magenta trace)Data from 11/3/05

File TEK00033

-0.045

-0.04

-0.035

-0.03

-0.025

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

-6.00E-08

-4.00E-08

-2.00E-08

0.00E+00

2.00E-08

4.00E-08

6.00E-08

CH1

CH220 ns/division

20 ns/division

10 mV/div

20 mV/div

5 mV/div


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Observations

• Structures are seen on traces from the prototype counters

• Both the SAPMT and the MAPMT traces show structures

• Structures appear over a ~50 ns interval• Pulse is more structured than expected if source

is ringing. • Connections to SAPMT are different from those

of MAPMT, suggesting not from impedance mismatch on MAPMT connections


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SAPMT Traces and Paddle TracesTrigger ACD, CH1 is S1, CH2 is B

-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

-5.00E-08

-4.00E-08

-3.00E-08

-2.00E-08

-1.00E-08

0.00E+0

0

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

CH1

CH2

Trigger ACD, CH1 is S1

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

-5.00E-08

-4.00E-08

-3.00E-08

-2.00E-08

-1.00E-08

0.00E+0

0

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

CH1

CH2

Paddle trace is on CH2, an 8”x8” scintillator with an 8575 PMT (magenta trace)Cosmic ray trigger

No structures on paddle traces

10 ns/div, 20 mV/div 10 ns/div, 10 mV/div


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Summary of Pulse Shape Studies

• Structures seen in traces seem to be from a fundamental property of the scintillation counters, and not specific to the MAPMTs or the connections to the MAPMTs

• A plausible explanation is that they are due to multiple re-emissions of scintillator light from the wavelength-shifters, which have a decay time of ~11 ns.

• We plan to test these (and other) scintillators with a faster wavelength shifter

• We abandoned the time-over-threshold method


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Assembly/Installation at MTEST


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Installed in MTEST


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Instrumentation for Tests

• Altogether there are 6x64 anodes plus 6 dynodes (390 channels)

• Of the 4 multipin connectors on each MAPMT box we connect only 1 connector at a time with an adapter to 16 coax connections.

• Within each group of 16 coax connectors we connect 3 cables to the ADCs, and we run cables to each of the 6 dynodes, for a total of 24 active channels (24 ADC channels).

• We chose to look at 3 adjacent strips at a time in each plane, to see the strip that is hit by the beam and the 2 adjacent strips.

• Coincidence logic set up


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Test Plan

• Measure response of scintillator strips to uniform beam of charged particles. Use MTEST beam of 120 GeV protons.

• Map out response vs position along lengths of strips and response for various strips. Compare single readout and dual readout modules. Avg number of photoelectrons.


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Summary of Setup and Runs• 4 planes installed in MTEST Feb 20.

• Cabling and logic completed for 24 channels.

• Had ~2 shifts of data taking before shutdown on Feb 26.

• Some units not fully working, but some preliminary results were obtained

• We resume testing in June after shutdown.


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Preliminary Result – ADC Spectrum, 5000 eventsRun 6: Counter S+, Strip 29(n) center

0

50

100

150

200

250

300

5 35 65 95 125

155

185

215

245

275

305

335

365

395

425

455

485

ADC Channel

Nu

mb

er o

f E

ven

ts

Frequency

edesta

- Pedestal at ~channel 65, with 10X amplifier- Peaks at ~channels 95, 125, 155, 185, 215, 245, 275, …- Correspond to 1, 2, 3, 4, 5, … photoelectrons- Mean number of photoelectrons is ~6- At 0.25 pC/channel, 30 channel separation between peaks yields gain of 4.5 x107 (amplified), or 4.5 x106 (unamplified)


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Conclusions and Next Steps

• Study of pulse shapes showed that time-over threshold is not feasible with these modules, need ADCs or other integrators for charge.

• Apparatus now in MTEST, main testing in 2H06• Plan to also test with Muons in MTEST• Plan to build on-detector digitizer/ADC• Future plans to build/test prototypes with faster

W.L. shifter• Interested in using Si PMTs and compare with

MAPMTs


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Backup Slides – Snowmass Results


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Update on Testing At FNAL

• New Test Setup in Lab 6 with Fermilab Support

• Testing Two New Prototype ILC Muon Counters from Notre Dame U. (#1 since 7/12/05, #2 since 8/10/05)

• Tests of Single Scintillator Strip From NIU• MAMPT Installed, Testing has Begun, UC

Davis Readout System w/CAMAC modules


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Amp

Amp

Disc

aANDb

aORb

Da

Db

Disc

DiscBeam

ADC

Narrow

AND

AND

Scaler

ScalerDisc

Wide

Logic Gate

ADC Gate

ADC

BASIC LOGIC FOR DUAL MODULES


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Summary of Source Tests – Central Region

• Found low yield from Proto #1, Strip 41, probable bad fiber splice

• Rates decrease by 10-20% between strips 20 and 44 at constant distance along scintillator. Probably loss in clear fiber. 15% loss in 1.25m 7.7m attn length

• Rates decrease by 20-25% along Strips. Corresponds to ~4-6m attn length in scintillator and wavelength shifter, as expected.


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Cosmic Ray Test Results: Prototype #1 Mainly

• ADC Spectra yield Means of 110-160 channels above pedestal at .25 pC/channel

• Means correspond to ~6 to 8 P.E.s for M.I.P – a 2X improvement over pre-prototype

• Typical ADC run has ~2% pedestals --> ~4 P.E.s• Proto #1 efficiency ~90% at disc threshold of 50

mV. Small Plateau. Proto #2 efficiency ~98% at 30-35 mV.

• Currently Mapping ADC spectra with cosmic triggers


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Tests of Single Scintillator Strip

• Single 1m long strip provided by NIU• Wavelength shifter fiber extends 15 cm past end• PMT near end of shifter fiber• Tested with Cs137 source and cosmic rays• Source tests show attenuation length of ~4.6m.

Nominal scintillator attenuation length is 5m.• Cosmic rays consistent with source tests• Measured ~8 PEs output


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Scintillator Strip Data

Cs137 Source Counts vs Position

30000

40000

50000

60000

70000

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38

Distance Along Strip (in)

Co

un

ts p

er 1

5 S

ec

Singles Rate

Cosmic Rays - NIU Scintillator

0.37

0.38

0.39

0.4

0.41

0.42

0.43

0.44

0.45

0.46

0.47

0.48

4 6 8 10 12 14 16 18 20 22 24 26 28 32 36

Distance from PMT End (in.)

Tri

ple

s/D

ou

ble

s


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Next Steps

• Calibrate MAPMT• Use MAMPT with UCD readout system, study

time over threshold to pulse height relation and response of individual strips.

• Improve MAMPT connector box and add magnetic shielding

• Test LED /PIN calibration system• Continue cosmic ray mapping• Test next set of prototypes that collect light at

both ends of scintillator strips.

ilc prototype muon scintillation counter tests

Documents

abrams lcws06 bangalorechart1

single pmt proto

cosmic ray tests

sapmt single anode pmt

counter s2

module2 modules

cosmic ray triggersch1

results of source tests