FPIX0 Electronic Test

1
FPIX0 Electronic Test

• Marina Artuso
• Paul Gelling
• Jianchun Wang

• The system works fine with charge injection
  calibration
• Gain curve, threshold, and noise calibration
• Americium source calibration

2
FPIX0 Chip
3
Gain Curve Calibration
High Gain Cell

• Scan step
• 1mV 31.25 e

Normal Gain Cell
4

• Efficiency curve around threshold
• can used to measure both noise and threshold

Attenuation factor 0.31826
5
Threshold Distribution
Threshold Voltage set to 1.95 V
6
Noise Distribution
7
Calibration with X-ray Source

• Americium-241 60 KeV (35.7)
• Peak expected Q 60 / 3.6 16.7 Ke
• Charge ADC curve from pulse calibration applied

Number of Clusters
60 KeV peak
Qcluster (Ke)
8
Am-241 with Al Filter
9 mm (later 4 mm) Al filter used lower energy
peak is suppressed
9
Relative Scale Calibration
220,000 Clusters recorded for 11 ? 63 cells
10
Peak Position Distribution
11
Scale Correction
Single Point (60KeV) Calibration ? Scale
Factor only
12
Summary

• Pulse and source calibrations so far work fine,
  and can be used for future test
• Strong X-ray source, more point calibration
• Laser beam is much better choice ( investigating
  )