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Below we describe common mode correction algorithms implemented used in

• psana module ImgAlgos::NDArrCalib. This correction along with others can be applied to raw ndarray under control of the psana configuration file for specified detector, for example for  Epix100a:

[ImgAlgos.NDArrCalib]
source  = DetInfo(:Epix100a)
key_in  = ndarray-raw
key_out = ndarray-clb
do_peds = yes
do_cmod = yes
do_stat = yes
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where keywords do_peds and do_cmod should have value yes or true in order to turn on pedestal subtraction and common mode correction algorithms.

• Detector.PyDetector package which provides uniform access to calibration and data for all detectors.

Low level implementation of the common mode correction algorithms is done in class ImgAlgos::CommonModeCorrection which uses methods from ImgAlgos::CommonMode.

Each algorithm may load file with parameters from calibration directory, which by default accounts for experimnet, calibration version, data source, calibration type and run range:

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Content of this file depends on detector, calibration type, and algorithm, as shown below.

Algorithms

In module ImgAlgos::NDArrCalib we We use algorithms earlier developed for CSPAD and other detectors and currently residing in ImgAlgos and  psalg packages.

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Other parameters are not used.

#5 Unbond pixels common mode correction for CSPAD and CSPAD2x2

In latest version of CSPAD (including 2x2) detectors a group of pixels is not bound to relevant electronic channels. Signal from these channels can be used to evaluate common mode variation of the sensor. Typical common_mode  control parameters:

5 50

where

• par[0] - algorithm #,
• par[1] - maximal allowed correction value.

Test of the common mode correction for pnCCD

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