The Program detcal_gui

The detector calibration can be done off-line (say, on your laptop) as long as you have the files I told you to record above. If you want to reuse existing calibration parameters, you should have a full calibration file (say, sidet_calibration_stxmi.dat) available, or some other valid file as mentioned below.

Start the calibration program in IDL:

    IDL> detcal_gui, sidet_n_segments=8

The number of segments has to be specified at the start and can't be changed during the calibration session. It defaults to eight, so you don't have to specify it until we get the new chips with more segments.

To a certain degree, the calibration steps can be done independent of each other, and existing calibration parameters can be reused. The following describes how certain existing parameters can be read into detcal_gui and how certain parameters can be written out. If you attempt to write out a parameter which hasn't been read in or determined yet, the program will raise an error.

All parameters:

From "File" / "Read Calibration File", you can read in all, or any combination of, parameters from an existing calibration file (like sidet_calibration_stxmi.dat). A window will pop up which asks which parameters to read. Then you can choose the file.

From "File" / "Write Calibration File", you can write out all parameters to a calibration file. If some parameters are missing (if they haven't been read in or determined before), the program will raise an error.

For the syntax of the calibration file, look at an example like cvs/idl_local/stxm5/test_data/sidet_calibration.dat. Note that all vector and matrix entries in that file have sm_par_n_adc_channels entries (which is 16), where all entries above sidet_n_segments are filled with zeroes.

Crosstalk Matrix:

From "File" / "Read Crosstalk Matrix", a crosstalk matrix can be read. It must be a plain ASCII text file with only the matrix in it. The entries in one line can be separated by spaces or commas. The matrix must have either sidet_n_segments$^2$ or sm_par_n_adc_channels$^2$ entries (i.e., $8^2$ or $16^2$).

From "File" / "Write Crosstalk Matrix to File", the matrix can be output to a file.

c_tune / mvolts_per_femtocoulomb:

This parameter was called c_tune in STXM 4 and is called mvolts_per_femtocoulomb in STXM 5. You can read it from a file like c_tune_stxmi.dat by "File" / "Read C Tune File". The file must be plain ASCII and must have sidet_n_segments or sm_par_n_adc_channels entries in one line, separated by spaces or commas.