1. EIC Tracking Meeting, March 26, 2012
Update on GEM Tracking R&D at Florida Tech & Plans and Requests for EIC proposal Marcus Hohlmann
EIC Tracking Meeting, March 26, 2012

2. EIC Tracking Meeting - M. Hohlmann
R&D Update
3/26/2012
EIC Tracking Meeting - M. Hohlmann

3. First Test of Zigzag Readout
2 sets of 10cm zigzag strips with different zigzag pitch (along strip)
24 fine
zigzag
strips
24 coarse
zigzag
strips
CAD Design by C. Pancake, Stony Brook
LEMO footpads
APV25
Hybrid
(using 38% of ch.)
+ SRS
Readout Board
for std. CERN
10cm×10cm
Triple-GEM Detector
2 mm
2 mm
First commissioning step:
Measure pedestals and compare with regular straight strips
Does the noise increase substantially due to the
increased strip area and capacitance?
BNL/FIT/SBU Collaboration
Work done by grad. students Mike Staib & Vallary Bhopatkar
3/26/2012
EIC Tracking Meeting - M. Hohlmann

4. Pedestal Distributions
12-bit SRS ADCs (4096 count range)
Std. Triple-GEM with 10cm long straight strips
Open Readout Board with 10cm long zigzag strips
# ev.
per
ch.
# ev.
per
ch.
APV ch. 31
ADC channel
ADC channel
pedestal width: rms 3.1 → 3.7 cts.
# ev.
per
ch.
# ev.
per
ch.
APV ch. 63
ADC channel
ADC channel
3/26/2012
EIC Tracking Meeting - M. Hohlmann

5. Pedestals for 128 channels
Open Readout Board with 10cm long zigzag strips
Pedestal width (rms)
[ADC counts]
Channels connected
to LEMO footpads (5)
48 channels connected
to zigzag strips (24+24)
channels not connected
APV channel number
3/26/2012
EIC Tracking Meeting - M. Hohlmann

6. Pedestal Distributions
Readout Board with 10cm long zigzag strips covered with one GEM foil placed 2 mm above induction plane:
# ev.
per
ch.
APV ch. 31
ADC channel
pedestal width: rms 3.7 → 3.9 cts.
# ev.
per
ch.
APV ch. 63
ADC channel
3/26/2012
EIC Tracking Meeting - M. Hohlmann

7. Pedestals for 128 channels
Readout Board with 10cm long zigzag strips covered with one GEM foil placed 2 mm above induction plane:
Pedestal width (rms)
[ADC counts]
48 channels connected
to zigzag strips (24+24)
Channels connected
to LEMO footpads (5)
channels not connected
APV channel number
3/26/2012
EIC Tracking Meeting - M. Hohlmann

8. R&D Conclusion & Outlook
Noise increases only by 1.5 ADC counts on zz compared w/ straight strips (~ 0.1% of range)
Encouraging! Even longer strips might have low enough noise for good measurements. Will also build a prototype with 30cm long zz strips.
Next:
Put Triple-GEM stack on zigzag r/o board
Sandwich between 2 straight-strip GEM detectors
See how well we can measure spatial resolution of the zigzag-strip detector using tracked cosmics
Produce & test boards with gold-plated zigzag strips
3/26/2012
EIC Tracking Meeting - M. Hohlmann

9. EIC Tracking Meeting - M. Hohlmann
2012 EIC Proposal INPUT
3/26/2012
EIC Tracking Meeting - M. Hohlmann

10. Input for Proposal Form a “forward tracking” working group:
BNL (?), FIT, U Va., & hopefully others !?
Propose to propose for forward tracker R&D :
Design & construction of 1-3 full-size, large-area, low-mass, trapezoidal prototype GEM chambers:
2 w/ zigzag strips and 1 w/ straight strips (as ref.)
SRS: investigate other chips w/ trigger (Beetle?)
Prototype tests:
Bench tests at home institutions (cosmics, x-ray, source)
Beam tests (in magnet!?, e.g. at CERN via RD51?)
Goal: Full slice test with e.g. 3 tracking stations in beam
9/4/2011

11. Very rough budget estimate
Equipment & material ~$85k
3 full-size prototype detectors ~$30k (CERN est.)
GEM frames w/ various spacers (UVa.) ~$ 5k
3 large r/o boards (2 zz &1 straight str.) ~$15k
mech. stretcher for large foils (UVa.) ~$10k
SRS electronics ~$20k
Materials (gas, cables, …) ~$ 5k
Personnel ~$150k
12 mos. Postdoc (fully loaded) ~$85k (FIT rate as example)
(alternative: grad student) (~$30k)
1 mo. Postdoc (UVa., fully loaded) ~$10k
Engineering support (0.5 FTE) ~$50k (??)
Undergrad. support (UVa.) ~$ 5k
Travel
Beam tests (at CERN in magnet?) ~$10k per yr
TOTAL (shared among inst.) ~$245k for year 1 (1&2?)