Shower Detector Channels Stability Control

Shower detector channels stability is controlled through the magnitude of its calibration coefficients values changing in the time during experiment.

Software for the shower detector channels stability control was developed and used for checking of channels stability during two experiments -- e89003 (May-June 1997) and e91026 (September-December 1997).

All programs and data files, which are used during stability control performance are in the directories:
/work/halla/com97/armen/e89003/sh_calib -- for experiment e89003, and
/work/halla/com97/armen/e91026/sh_stab -- for experiment e91026.

The sequence of steps for stability control performing looks as follows:

1.

Select a number of run data files distributed uniformly on the creation time in whole of experiment period.

2.

Calculate the calibration coefficients of shower detector channels for all of selected data files. Calibration on all of statistic into each of selected files is desirable.

3.

View the graphics of calibration coefficients values changing during the time. For any channel, such a graphic of coefficient value versus time (or versus run number) must be around of a horizontal straight line. Any large deflection from this line must be considered separately, in order to determine the reason of the deflection.

Step 2 is made by using the shower detector channels calibration procedure in ESPACE, as it described in sec.2.2. Example of such an ESPACE kumac program text is in shcal.kumac file. In result of this program execution the computed calibration constants files shower_calib_rXXXX.dat (where XXXX is the run number of data file) for all of scanned data files are created. Besides, shcal_stat.XXXX files containing an information which shows which channels was calibrated and which channels was not calibrated by data of run XXXX, for each of calibration data files are created. (About calibrated and uncalibrated modules see ESPACE program shcal_dofit in sec.3.2).

For the step 3 realization a PAW kumac program sh_stab.kumac has been used, which:

• Gets the least and the greatest numbers of runs, between which numbers of calibration data runs are found. These run numbers interval bounds must be given by user either as a parameters of PAW macro, or from terminal as an answer of program question.
• Shows graphics of calibration constants values of all channels of shower detector. Two graphics (one for Preshower and one for Shower) are plotted for every run, by data of which calibration constants have been calculated. On these graphics, the points, corresponding to the calibrated and uncalibrated modules coefficients are signed by the different markers (an 'asterisk' for calibrated, and a 'bullet' for uncalibrated). For each of run number XXXX in the given interval, calibration constants are read from the shower_calib_rXXXX.dat files. Calibrated and uncalibrated modules are identified by statistic information in the shcal_stat.XXXX files. Calibration constants file and statistic information file are read by calling the fortran routine consrd.for.
• Shows graphics of calibration constants values changing during the time. For this, for every shower detector channel, a graphic of constant value versus the sequential number of run (by data of which this constant has been calculated) is plotted.

After the execution of sh_stab.kumac program, a postscript file sh_stab.ps containing all of graphics, which are plotted on the display during execution, is created.

  
Figure 3: Values of calibration constants computed by data of run 1264 for Preshower (a), and Shower (b) channels versus channel number. ('asterisk'-s are corresponding to the calibrated modules coefficients, and 'bullet'-s, to the uncalibrated). Graphics of constants values changing during the time for the certain channels: module 23 of Preshower (c), and module 52 of Shower (d) (constant value versus the sequential number of run in the given interval of run numbers).

Fig.3 contains a four graphics among that, which are plotted during execution of program sh_stab.kumac.

Fig.3(a) and Fig.3(b) show graphics of values of calibration constants computed on beam data of run 1264 for Preshower and Shower channels, respectively. Du to the small statistic (or no statistic) on the boundary modules, these modules have not been calibrated, and its calibration constants values stay the same as its initial values. In these graphics 'asterisk'-s are corresponding to the calibrated modules coefficients, and 'bullet'-s, to the uncalibrated.

Fig.3(c) and Fig.3(d) show graphics of constants values changing during the time for two of more statistical modules in central part of Preshower (module 23) and Shower (module 52), respectively. Along the $X$-axis sequential numbers of runs in the given interval of run numbers are shown. Along the $Y$-axis -- values of calibration constants, computed by data of each of run.

These graphics was obtained after the processing the 19 selected run files for the shower detector channels stability consideration during the e91026 experiment. The same processing has been done over the data of 30 run files, selected among the e91026 experiment data files. Quality of shower detector channels stability during both of experiments is good.

Note 1: For shcal_stat.XXXX file creation (where XXXX is the run number of data file) some additions in my own version of ESPACE program shcal_dofit (see sec.3.2) have been made.

Note 2: Versions of programs for experiment e91026 data processing are described before. Versions of programs for experiment e89003 data processing are a little different.