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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.
Calibration
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procedure
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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Gains (G) for switching gain modes AHL-H, AHL-L, AML-M, AML-L
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Mean values
| Fixed gain mode | FH | FM | FL |
|---|---|---|---|
| pedestal | 3392 | 3293 | 3277 |
| Switching gain mode | AHL-H | AHL-L | AML-M | AML-L |
|---|---|---|---|---|
| pedestal H(M)-from dark, L-evaluated | 3332 | 1825 | 3295 | 2601 |
| offset (B) from fit | 4584 | 3077 | 3679 | 2985 |
| offset (B) difference H(M)-L | 1507 | 694 | ||
| gain (G) from fit | 47 | 0.52 | 15.4 | 0.49 |
Denote
- p - pedestal
- B - fit base-level offset parameter, <intensityADU> = B + G * <event-index-from-0-pulser>
- G - gain
Current (plots above and results in table) naive version of L-pedestals evaluation
- pL = pH - (BH-BL)
Gabriel's version
- pL = BL - (BH-pH)*GL/GH
L-pedestals using Gabriel's formulae for AHL-L and AML-L
Questions
- do we need to account for the difference between offset (B) and pedestal (Gabriel's version)
- the same difference may be between fit 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?
2020-06-22 ASIC issue
detdaq18 run 52
Panel 14 (counting from 0) /reg/g/psdm/detector/gains/epix10k/panels/0000000001-0175696641-1056964630-1010951301-0019435010-0000000000-0000000000
Data for a few charge injection points
Injected charge or gain is too small to switch to L-gain mode...
Gains AHL-H, AHL-L, AML-M, AML-L
Panel 14(next-to-last) charge injection in ASIC1 does not work
2020-06-24 calibration constants for ALL gain ranges and panels
detdaq18 run 52
pL were evaluated using Gabriel's formulae.
plots for pedestals, pixel_rms, pixel_status, pixel_gain (default), gain from charge injection
deployed as
/reg/d/psdm/det/detdaq18/calib/Epix10ka2M::CalibV1/DetLab.0:Epix10ka2M.0/*/52-end.data
SHAPE (7,16,352,384) : 7-gains, 16-panels of shape (352,384)
References
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Overview
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