ILC Prototype Muon Scintillation Counter Tests

Transcription

1 ILC Prototype Muon Scintillation Counter Tests Robert Abrams Indiana University August 23, 2005 ALCPG R.J. Abrams 1

2 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. (S1 since 7/12/05, S2 since 8/10/05) Tests of Single Scintillator Strip From NIU MAMPT Installed, Testing has Begun, UC Davis Readout System w/camac modules August 23, 2005 ALCPG R.J. Abrams 2

3 Test Setup Testing table holds 2 modules and 2 movable pairs of 20cm x 20 cm scintillation counters above and below prototype counter Source tests with 1mCi Cs137 gamma source mounted on transporter. Improved collimator (2 thick Pb). Single Anode PMT: Hamamatsu E element MAPMT: Hamamatsu H7546B August 23, 2005 ALCPG R.J. Abrams 3

4 Prototype S1 with Single PMT August 23, 2005 ALCPG R.J. Abrams 4

5 Prototype S1 with MAPMT, Prototype S2 in Place Above it August 23, 2005 ALCPG R.J. Abrams 5

6 Prototype S1 with MAPMT, Prototype S2 with Single PMT August 23, 2005 ALCPG R.J. Abrams 6

7 MAMPT Connector Box August 23, 2005 ALCPG R.J. Abrams 7

8 Prototype Muon Detectors Module dimensions 1.25m x 2.5m Constructed at Notre Dame University (See M. Wayne talk at this conference 64 scintillator strips at 45 degree angle to edges 2 modules built, at +/- 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 August 23, 2005 ALCPG R.J. Abrams 8

9 Scintillator Strip Layout Simplified 64 PMT Prototype S1 Cookie Clear fibers to cookie (Readout Side) 1 Clear fibers to cookie (Readout Side) 1 PMT Prototype S2 Cookie August 23, ALCPG R.J. Abrams 9

10 Prototype S1 Source Map Source Map Prototype #1 Counts/30s cm cm cm 87.6 cm 64.5 cm 43.2 cm 21.6 cm Strip Number Distance Along Strip August 23, 2005 ALCPG R.J. Abrams 10

11 Prototype S2 Source Map Source Map Prototype #2 Counts/30s cm cm cm 87.6 cm 64.5 cm 43.2 cm 21.6 cm Strip Number Distance Along Strip August 23, 2005 ALCPG R.J. Abrams 11

12 Response vs Strip Number Source Counts for vs Strip Number for Various Distances Along Strips - Prototype S1 Source Counts for vs Strip Number for Various Distances Along Strips - Prototype S Counts per 30 sec cm 43.2 cm 64.5 cm 64.5 cm 87.6 cm cm cm cm Counts per 30 sec cm 43.2 cm 64.5 cm 64.5 cm 87.6 cm cm cm cm Strip Number Strip Number August 23, 2005 ALCPG R.J. Abrams 12

13 Source Count vs Distance From Readout Side (Strips 14-26) Source Counts vs Distance Along Strip Prototype S1 Source Counts vs Distance Along Strip Prototype S Counts per 30 Sec Strip 17 Strip 14 Strip 20 Strip 23 Strip 26 Counts per 30 Sec Strip 17 Strip 14 Strip 20 Strip 23 Strip Distance from Readout side (cm) Distance from Readout side (cm) August 23, 2005 ALCPG R.J. Abrams 13

14 Source Counts vs Distance from Readout Side (Strips 29-41) Source Counts Along Strips Prototype S1 Source Counts Along Strips Prototype S Counts per 30 sec Strip 29 Strip 32 Strip 35 Strip 38 Strip 41 Counts per 30 sec Strip 29 Strip 32 Strip 35 Strip 38 Strip Distance from Readout Side (cm) Distance from Readout Side (cm) August 23, 2005 ALCPG R.J. Abrams 14

15 Source Counts vs Distance from Readout Side (Strips 44-59) Source Counts Along Strips Prototype S1 Source Counts Along Strips Prototype S Counts per 30 Sec Strip 44 Strip 47 Strip 50 Strip 53 Strip 56 Strip 59 Counts per 30 Sec Strip 44 Strip 47 Strip 50 Strip 53 Strip 56 Strip Distance from Readout End Distance from Readout End August 23, 2005 ALCPG R.J. Abrams 15

16 Summary of Source Tests Central Region Found low yield from Prototype S1, Strip 41, possibly fiber splice damaged in transit 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. August 23, 2005 ALCPG R.J. Abrams 16

17 Cosmic Ray Test Results: Prototype S1 Mainly ADC Spectra yield Means of 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 mv. Mapping ADC spectra with cosmic triggers progressing. August 23, 2005 ALCPG R.J. Abrams 17

18 MPMT Result: Source Spot Size Individual Strips read out from MAPMT Backgounds (no source) subtracted Shows typical spread of source counts is 1-2 strips wide From geometry, expect ~25% in adjacent strips Counts per strip Source Profile - MAPMT Results Strip number Source at Strip #28 Source at Strip #30 August 23, 2005 ALCPG R.J. Abrams 18

19 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 August 23, 2005 ALCPG R.J. Abrams 19

20 Scintillator Strip Data Cs137 Source Counts vs Position Cosmic Rays - NIU Scintillator Singles Rate Counts per 15 Sec Triples/Doubles Distance Along Strip (in) Distance from PMT End (in.) August 23, 2005 ALCPG R.J. Abrams 20

21 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. August 23, 2005 ALCPG R.J. Abrams 21