Upload
debra-hodge
View
224
Download
0
Tags:
Embed Size (px)
Citation preview
TRD R&D at GSI
Results from test beam 2004 Plans for test beam Feb. 06 Measurements with X-ray stand
C. Garabatos, GSI
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 2
TR + tracking
• rejection ≤ 10–2
• position resolution ~300 m
• particle load: 105 Hz/cm2
• < 100 ns shaping time
• material budget
• reliability (stability, ageing, ...)
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 3
Solutions under study
• Classical wire chambers
• GEMs
• Straw tubes
• Name: Transition Radiation Detector
GAS
RADIATOR
6 mm
2-4 mm
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 4
Resolution vs. rate (July 04)(E. Jiménez)
0 20 40 60 80 100 1200
100
200
300
400
(
m)
Rate (kHz/cm2)
GSI MWPCs
• Slight degradation with rate• Pad size not optimized
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 5
9o incident angle
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 6
Pad response function
Next: go from 7.5 mm to 7.0 mm pad width
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 7
Next test beam Feb. 2006
• Dedicated test beam line in cave C (HTD)
• Higher rates with N2 source (factor ~5)
• Improved set-up– Trigger counters– Chamber pad planes– Readout electronics
• Dense program
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 8
Beam profile in HTD
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 9
Trigger scintillators for test beam
2004
4x4 cm2 plastics
2006
4x 1x4 cm2 plastics
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 10
Pad geometryfor new prototypes
2004 2006
ALICE geometry: 7.5x70 mm2 CBM geometry: 7x16 mm2
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 11
Readout electronics(H. K. Soltveit)
• New 0.35 m CMOS 16 channel PASA
• Submission end of September
• Enough chips for all test detectors
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 12
Chip parameters (H.-K. S.)
Performance Specified Simulated (typical)
Noise 1000e for pad capacitance between
5- 10pF
350e@5pF
412e@10pF
660e@25pF
Conversion gain 12 mV/fC 12.6 mV/fC
FWHM 70 ns 70 ns
Undershoot - 1mV
Baseline shift - 3mV
Pad capacitance 5-10 pF -
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 13
Program• High rate performance vs.
– Detector flavour and geometry– Gas gain– Gas composition– Incident angle
• e/ separation vs. radiator type (low rates)– Foil radiator
• p/ separation at high rates
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 14
Measurements with X-ray tube
(F. Uhlig, G. Hamar)
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 15
Measurements with X-rays
• Possibility to measure rate dependence on gas gain and gas composition
• Need careful calibration and extrapolation to charged particles
• Easy
• Same set-up will be used for ageing tests
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 16
Results with Argon
• Fit to Mathieson's formula ln(G/G0)/G = K R The constant K characterises the chamber and the gas• Next: Xenon
10 100 1000 100002000
10000
50000
100000
Gai
n
Rate (kHz/cm2)
Ar-CO2 [90-10]
10%5%2%1% gain drop
10 100 1000 100002000
10000
50000
100000
Gai
n
Rate (kHz/cm2)
Ar-CO2 [70-30]
10%5%2%1% gain drop
IWTRD Cheile Gradistei 24-28.09.05
C. Garabatos, GSI 17
Conclusions and outlook
• We start to know what we need
• Tracking and TR-ID with MWPC seem feasible at CBM
• High rates and final performance will be an outcome of – specific, ongoing R&D – detailed, incipient simulations