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This note describes raw intensity correction algorithms in the method Detector.calib and their variation on detector type.
det.calib algorithms
Generic form of this method is
LCLS Detector Interface
Method calib
arr = det.calib(evt, cmpars=None, **kwargs)
Regular sequence of applied algorithms
- dark correction - pedestals subtraction from using calib/.../pedestals
- common mode correction depending on cmpars or calib/.../common_mode or default from PSCalib.CalibParsBase*V1.py
- gain correction with gain factors from calib/.../pixel_gain. Depending on detector pixel_gain calibration array may contain per-pixel gain in ADU/keV or gain correction factor gfactor in keV/ADU, where gfactor=1/gain.
- apply mask depending on **kwargs
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Correction formula
: (common_mode(raw - peds))/gain * mask(**kwargs)
or for gain factors in pixel_gain:
(common_mode(raw - peds))*gfactor * mask(**kwargs)
Mask
To construct the mask use **kwargs and algorithms from method mask_v2 from AreaDetector.
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| Detector type | pedestal subtraction | common mode correction | pixel_gain content, by default gain factor | gain | mask | formula | comments |
|---|---|---|---|---|---|---|---|
| LCLS (1) | |||||||
| CSPAD | + | default cmpars = (1, 25, 25, 100) cmpars = 0 or cmpars[0] = 0 | gain factor, keV/ADU | *gainmask det.set_gain_mask_factor(gfactor=6.85) | + | gain map extracted from detector configuration data and applied with gfactor gainmask is applied before regular gain factor | |
| CSPAD2x2 | + | shape=(185, 388, 2) → common_mode shape=(2, 185, 388) → back to (185, 388, 2) default cmpars = (1,25,25,100) | gain factor, keV/ADU | + | + | shape is converted before common mode correction in order to apply regular CSPAD algorithm then it is converted back to daq shape. | |
| epix100a | + | default cmpars =(4,6,30,30) | gain factor, keV/ADU | + | + | ||
| pnCCD | + | default cmpars =(3,350,350,128) or alg #8 (8,5,500) | + | + | |||
| Andor3d | + | default cmpars =(2,10,10,cols) | + | + | |||
| Princeton | + | default cmpars =(1,50,50,100,1,size,1) | + | + | |||
| Camera | + | other Cameras default cmpars = (0,0,0,0), cmpars = 0 or cmpars[0] = 0 - OFF | + | + | |||
| epix10ka | + |
| gain, ADU/keV | pixel_gain constants are used and per event depending on gain range | + | (common_mode(raw - peds)/gain * mask | UtilsEpix10ka.calib_epix10ka_any(det, evt, cmpars=None, **kwa) offsets are already accounted at deployment of pedestals in calib/.../pedestals |
| Jungfrau | + | applied for pixels in high gain mode only in combination with mask
| gain, ADU/keV | pixel_gain and pixel_offset are used and per event depend on gain range | + | (common_mode(raw - peds - offset))/gain * mask | UtilsJungfrau.calib_jungfrau(det, evt, cmpars=(7,3,200,10), **kwa) |
LCLS-II Detector Interface
Method calib
arr = det.raw.calib(evt, **kwa)
Regular sequence of applied algorithms
- dark correction - pedestals subtraction using constants of ctype
pedestalsfrom DB - common mode correction depending on cmpars or constants of ctype
common_modefrom DB - gain correction with constants from DB for ctype pixel_gain. In LCLS-II we intend to always use in pixel_gain constants the gains in ADU/keV.
- mask is not applied by default (see below)
Correction formula
common_mode(raw-peds)/gain
Mask
In lcls2 mask is derived and applied separately as explained in Area detector mask examples or Detector interfase in LCLS-II.
TURN OFF common mode correction
cmpars=None - use constants from DBcmpars[1] = 0 - OFFboth cmpars=None and common_mode constants are missing in DB - common mode correction is OFF
Detector dependent algorithms
Spreadsheet below contains comments on detector specific application
| Detector type | pedestal subtraction | common mode correction | gain | mask | formula | comments |
|---|---|---|---|---|---|---|
| LCLS-II | ||||||
| epix10ka | + | default cmpars=None - search common_mode pars in DB. Correction is OFF if constants missing in DB. ex. (7,2,100,10) | + | - | (common_mode(raw - peds)/gain | calib_epix10ka_any(det.raw, evt, cmpars=None, **kwa) mask defined by **kwa is used in common_mode_correction see UtilsEpix10ka |
| epixhr2x2 | + | + the same as epix10ka | + | - | the same as epix10ka | |
| epix100a | + | + the same as epix10ka ex. (7,7,100,10) | + | - | calib_epix100(det.raw, evt, cmpars=None, **kwa) | |
| opal | + | - | + | - | (raw-peds)/gain | opal_base |
| piranha4 | + | - | + | - | (raw-peds)/gain | piranha4_base |
References
Overview
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