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Overview

The beamtime on July 21 is the final shift of the dec 2022 epix10ka calibration beamtimes. From the December beamtimes two primary problems were observed, the check mark problem for the small 10k's and 3 out of the 4 quads of the MFX 2M showing values that were too low after switching.


       Fig. 1 AML-L linearity behavior for small ePix10ka.           Fig. 2 AML-L linearity compared to FL linearity for small epix10ka.


Fig 3. The observed problem when switching for 3 of the quads for the ePix10k2M.1.


We believe the problem is due to the X-ray pulse arriving to early in the measurement cycle, and only partially within the ACQ window, For the upcoming beamtimes 4 detectors will be evaluated: epix10ka front facing (no. 27), epix10ka sidefacing 1mm Si, ePix10k2M.1, and a prototype of the ePix10ka non-ghosting ASIC (NG). For the first 2 shifts, the primary aims are (in order of importance):

  1. Evaluate the problems observed for the 2M and the smalls and correct these, so we can properly calibrate the smalls during the final beamtime.
  2. to evaluate the linearity and switching dependence on the total flux hitting the detector, i.e. pinhole experiment;
  3. to evaluate the magnitude of the tigerteeth in switching when running with CompEnOn and Off,
  4. evaluate the performance of the NG detector (linearity, switching, ghosting).

The aim of the final shift is to calibrate the small ePix10ka detectors when we have corrected the problems observed in december so we have valid calibration data for all detectors. For all 3 beam times, we will be set up to measure airscatter at different fluxes. Prior to going to the beamtime, the following work has to be done:

  1. DAQ scripts for time scan and intensity scans have to be identified and tested that they run,
  2. python visulisations for a few pixels that show both linearity (ADU vs. wave-8), and the timing scans (delay vs measured average intensity); evaluation of dropped shots to see if there is any persistance.
  3. as well as the scope setup allowing us to see the x-ray pulse position compared to ACQ window has to be verified and ready;


Experimental setup



Measurement plan

15 July 2023:

Primary focus:

  1. Timing scan for the small the small detectors to identify the ACQ window position. The very crudely measured transfer function performed during the december beamtime for the small 10k can be seen belo



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