This note describes calibration constants Data Base for LCLS-II.

Intro

In LCLS-II calibration constants resides in the data bases. Access to the DB can be done through python API, CLI, and GUI. At regular deployment calibration constants goes in two databases designated  for experiment and for detector. In regular request for calibration constants experimental DB is addressed first, then if constants not found, the detector DB is included in search. These features are sufficient for regular operations with detectors.

Calibration DB names

Calibration constants on MongoDB server are grouped in databases identified by their names

  • cdb_<experiment-name>
  • cdb_<detector-name>

for example

  • cdb_rixx45619
  • cdb_epixhr2x2_000001

Add constants to the DB

Constants can be deployed with commands cdb and epix10ka_deploy_constants, see for detail in psana environment:

  • cdb -h
  • epix10ka_deploy_constants -h

for example

  • cdb add -e rixx45619 -d epixhr2x2_000001 -t 2021-10-01T00:00:00-0800 -c pedestals -f mypeds
  • cdb add -e rixx45619 -d epixhr2x2_000001 -t 2021-10-01T00:00:00-0800 -c geometry -f mygeo -i txt
  • epix10ka_deploy_constants -e rixx45619 -d epixhr -r121 -D

DB management tool

Browsing and management of constants in calibration DB can be done with command

launching multipurpose GUI application.

Get corrected data

Example of script to get raw and corrected data in psana environment:

from psana import DataSource
ds = DataSource(exp='rixx45619', run=121)
det = run.Detector('epixhr')
raw = det.raw.raw(evt)
arr = det.raw.calib(evt)
img = det.raw.image(evt)

Direct access to calibration constants

For details see Area Detector Interface - Calibration Constants

All detector calibration constants (np.array) and associated metadata (dict) are available through the dictionary det.calibconst with calibration type as a key. For example,

peds, meta = det.calibconst['pedestals']

Possible calibration types: pedestals, pixel_status,  pixel_rms,  pixel_gain, pixel_mask, etc.

References

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