1. The first signal of GEM-TPC
2004/03/12
ODA, Susumu
GEM check using X-ray source (55Fe) and P10 gas.
GEM-TPC signal using P10 gas and LASER.
GEM-TPC signal using CF4 gas and LASER.
Preamplifier
Pad shape

2. 1. GEM check using X-ray source (55Fe) and P10 gas
Setup
(inside TPC)
VGEM = 355 V
VGEM = 334 V
Main peak and escape peak were observed.
I thought triple GEM worked well.

3. 2. GEM-TPC signal using P10 gas and LASER
VGEM = 350 V
Edrift ~ 220 V/cm 1 2 3
LASER 1 2 3
LASER
GEM-TPC signals from LASER
were observed.
GEM-TPC worked well in P10 gas.

4. 1 2 3 4 ADC value of LASER signal increase with VGEM.
Cosmic ray signal
VGEM = 329 V
Edrift ~ 230 V/cm 1 2 3 4

5. 3. GEM-TPC signal using CF4 gas and LASER1 2 3 4
Cosmic ray signal
VGEM = 510 V
mean – pedestal vs. VGEM
LASER signal
GEM-TPC worked well
in also CF4 gas.
GEM tripped at VGEM
= 550 V. (gain~2x104)
Edrift ~ 400 V/cm

6. 4. Preamplifier
Isobe-san type preamps.

7. I used this type preamp for above measurements.

8. 5. Pad shape CERN, Karlsruhe Univ. etc. Carleton Univ. etc.
1.27 x 12.5 mm2
Carleton Univ. etc.
2 x 6 mm2　physics/

9. * 1.5 x 10 mm2 ??
* Use 2FADCs or 3FADCs
* Compare with rectangle and zigzag
* X-direction resolution using 3 rows : X2-(X1+X3)/2
* Large pads for Drift velocity measurement