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<calibrated-data> = (<raw-data> - pedestalspedestal) * <gain-factor>
where pedestals and <gain-factor> are per-pixel map combined from 7 gain mode maps.
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Accumulate dark data and evaluate pedestals for pedestal for five gain modes:
- 5 calib-cycles: FH, FM, FL, AHL-H, AML-M (gain is not switching in dark)
and 2x49 charge injection samples (see plots) where gain is switching: - 7X7 calib-cycles: AHL
- 7X7 calib-cycles: AML
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Then, in current calibration procedure we evaluate pedestals pedestal for two leftover gain modes AHL-L, AML-L as
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Panel 2(counting from 0) /reg/g/psdm/detector/gains/epix10k/panels/0000000001-0175233793-0553648150-0743498629-0017156647-0000000000-0000000000
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Pedestal for fixed gain modes FH, FM, FL
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Pedestal for switching gain modes AHL-H and derived AHL-L AML-M and derived AML-L
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Offset (B) for switching gain modes AHL-H, AHL-L, AML-M, AML-L
Offsets difference H(or M) - L for AHL, AML
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Mean values
| Fixed gain mode | FH | FM | FL |
|---|---|---|---|
| pedestalspedestal | 3392 | 3293 | 3277 |
| Switching gain mode | AHL-H | AHL-L | AML-M | AML-L |
|---|---|---|---|---|
| pedestalspedestal | 3332 | 1825 | 3295 | 2601 |
| offset (B) | 4584 | 3077 | 3679 | 2985 |
| offset difference H(M)-L | 1507 | 694 | ||
| gain (G) | 47 | 0.52 | 15.4 | 0.49 |
Current version of pedestals evaluation
pedestals_L = pedestals_H(M) - <offset-difference-H(M)-L>
Questions
- do we need to account in the difference between offset and pedestal (Gabriel's version)
- the same difference may be between B(L) and pedestal_L or it is smaller due to the gain?
- is current procedure correct?
- if not,
- what is correct procedure?
- or what could we calibrate with charge injection?
References
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