1. 1 TRD-prototype test at KEK-FTBL 11/29/07~12/6 Univ. of Tsukuba Hiroki Yokoyama The TRD prototype is borrowed from GSI group (thanks Anton).

2. KEK-FTBL KEK, Fuji Test Beam Line 2007/11/29-12/6 3GeV/c,electron beam 2 Beam Area

3. TRD-prototype 3

4. 4 setup Scintillation Counter TRDMRPC PbGlass Trig for TOF

5. measurement Pad Response Function Amplification of signals (through anode voltage and gas dependence) Electron attachment (through drift voltage dependence) Drift velocity (through drift voltage and gas dependence) Absorption of TR-photon （ absorption length in 2type gases, Ar+CO 2 (85,15),Xe+CO 2 (85,15)) Angle dependence of position resolution

6. Pad Response Function distance from CM vs. proportion of induced charge to sum of them. Full width of signal sharing in azimuthal direction is 3pads. 6 Pulse height is defined as sum of three adjacent pad’s induced charges.

7. 77 Gas Gain Ar+CO 2 (85,15)Xe+CO 2 (85,15) Drift Voltage -2100V Anode Voltage 1500V 1450V 1400V 1350V 1300V Gas gain by avalanche can be fitted by exponential function of anode voltage Pulse height at Amp region Mean pulse height time Anode voltage Anode voltage vs pulse height Ar+CO2(85,15) Xe+CO2(85,15) Mean pulse height

8. 88 Drift velocity Anode Voltage 1500V Drift Voltage -2100V -2000V -1900V -1800V -1700V Drift velocity for Ar gas is about three times larger than that for Xe gas Drift Velocity Electric Field of Drift region Electric field vs Drift velocity Ar+CO2(85,15) Xe+CO2(85,15) time Ar+CO 2 (85,15)Xe+CO 2 (85,15) Mean pulse height

9. Electron attachment 9 The attenuation of signal by H 2 O or oxygen depends on time that electrons stay in the chamber. Attenuation of signal by electron attachment a/b is defined as sign of electron attachment. a b Stay time of electron a/b Ar+CO2(85,15) Xe+CO2(85,15)

10. 10 Anode Voltage 1500V Drift Voltage -2100V With Radiator Without Radiator beforeafter before after 10 TR-photon signal(1) Correct time distribution to be flat shape in the drift region time Ar+CO 2 (85,15) Xe+CO 2 (85,15)

11. TR-photon attachment Depth of detector from drift electrode(mm) Ar+CO2(85,15) Xe+CO2(85,15) 11 TR-photon signal(2) 11 Depth of TRD-prototype is 30mm. 95%(in Xe),28%(in Ar) TR-photon energy is absorbed. Calculate the TR photon contribution as the difference between time distributions with/without radiator. By slope of exponential fit, I calculated absorption length of TR-photon in each gas. absorption length

12. resolution in azumuthal direction 12 Data for fit Calculate center 1pad(=8mm) Resolution(angle 0°)is about 400μm 12 Pad number Measure difference between this point and fited line Angle=20° angleresolution 0°391±10μm 10°605±28μm 20°1071±22μm 30°1614±45μm time Pad number

13. summary Signal share is less than 3 pads. Gas gain by avalanche can be fitted by exponential function of anode voltage. Drift velocity in Ar gas is about three times larger than that in Xe gas. The attenuation of signal by hydrogen and oxygen depends on time that electrons stay in the chamber. absorption length in Xe(Ar) is 10mm(89mm) Resolution(angle 0°) is 391μm. 13