KEK Beam Test Efficiency studies and results

1
KEK Beam TestEfficiency studies and results
Dan Burke 21/04/06
2
Contents

• Efficiency Study
• Missing row hits
• Noise Study
• Use pedestal subtraction
• Reduce unwanted hits
• Preliminary Results
• Diffusion
• Resolution

3
Row Efficiency
4
B0.5T
On examining the missing row hits, it was seen
that hits were being lost on the edges
5
Pad usage
Row efficiency over 99.9
6
Noise Study
7
Average Pedestals
8
Amplitudes of hits on pads far from track
Overflow hits far from track - removed
9
Noise Study

• Removed overflow hits that are far from the track
  (gt4 pad widths)
• Removed hits that had time far from Track-Time
  (gt3.5 time buckets)
• Increased threshold due to excess noise
  (threshold increased to 8 DAC)

10
B0.5T
Average total charge steady over multiple rows
11
Diffusion Coefficients
12
Diffusion Coefficients
Magboltz Measured (preliminary)
B0T 492.3 µm/vcm 765 13 µm/vcm --data problems
B0.5T 284.1 µm/vcm 301 4 µm/vcm
B1T 192.6 µm/vcm 182 8 µm/vcm
Systematics to be studied (fitting, noise, etc.)
13
Resolution B 0 Tesla
NEFF 9.4 0.6
14
Resolution B 0.5 Tesla
NEFF 10.0 1.7
15
Resolution B 1 Tesla
NEFF 10.2 5.8
16
Resolution
17
Resolution