1. DRS4 news: from the Paul Scherrer Institute
Activities / News- Oct 5
DRS4 news: from the Paul Scherrer Institute
Hi Dan,
we are desperately waiting for the new series of boards to arrive from the manufacturer. They had problems with the PCB and had to redo it, leading to a delay of 1-2 weeks. So we hope that we will receive the boards in about ten days, and then start sending them immediately.
Best regards,
Stefan
Components here: drawings for final pieces in UM shop
all mechanical pieces are here
Stage is tested
To do:
Need a vessel support structure
Verify gas tightness of vacuum feedthroughs
Electronics readout interfaces: Bob
IEEE - knoxville: must prepare presentation: what is kosher to present at this time? We will discuss this content next week.
Possible beam test at CERN next month: Yan
Lab work here:
Yiftah arrives start of continuous lab presence for next 3 years
Latest test with Vishay panel

2. Sept 20, 2010
New Vishay panel. Filled with Ar/CO2 93/7 at 660 Torr
HV =
Pixel i= 1, j=17
HV on row I (Ni), Sense on col J (SnO2)
Column j = 1,N sense on j =17
Row i = 1,N sense on i =1

3. Background rate = 66/14 min= 4.7 /min
20 db attenuator inline
20 ns
5 V

4. New Vishay panel. Filled with Ar/CO2 93/7 at 660 Torr HV = - 1359
Sept 24, 2010
New Vishay panel. Filled with Ar/CO2 93/7 at 660 Torr
HV =
Pixel i= 1, j=17
HV on row I (Ni), Sense on col J (SnO2)
20 db attenuator inline
20 ns
File = vp01_pulse_1359V_001,txt
2 V

5. Oct 4, 2010 Reverse electrode hookup
New Vishay panel. Filled with Ar/CO2 93/7 at 660 Torr on Sept 20
HV =
Pixel i= 1, j=17
Sense on row I (Ni), HV on col J (SnO2)
Column j = 1,N sense on j =17
Row i = 1,N sense on i =1

6. Oct 4, 2010
New Vishay panel. Filled with Ar/CO2 93/7 at 660 Torr
HV =
Pixel i= 1, j=17
Sense on row I (Ni), HV on col J (SnO2)
20 db attenuator inline
20 ns
5 V

7. Oct 4, 2010 Reverse electrode hookup
New Vishay panel. Filled with Ar/CO2 93/7 at 660 Torr on Sept 20
HV =
Pixel i= 1, j=17
Sense on row I (Ni), HV on col J (SnO2)
Column j = 1,N sense on j =58
Row i = 1,N sense on i =16

8. A PPS Anti-detector! Minute 4 5 6 7 8 9 10 bkg SR-90 11 12 14 2 3
Measurements using SR-90 placed directly on pixel
HV = on SnO2 Pixel (I,j) = (16,58)
Background with source completely removed.
Minute 4 5 6 7 8 9 10
bkg
SR-90 11 12 14 2 3
background rate remarkably steady at ~ 1/min
In this configuration, the source suppresses discharges.
perhaps space charge from intense electron source reduces E field ?