1. Authors: Dmitrii Pereima, ITEP; Dmitry Golubkov, ITEP; Iouri Gouz, IHEP; Victor Egorychev, ITEP. Visualization of HCAL 137 Cs calibration data 1 CALO + upgrade meeting 14 June 2016

2. Motivation 2 Regular cesium calibration runs are necessary to provide required accuracy of energy reconstruction in HCAL. In addition, long time operation of the detector, with considerable radiation load, makes it necessary to follow-up (monitor) calorimeter performance with changing beam intensity and integrated recorded luminosity (aging). To simplify and make the calibration procedure more convenient a GUI application is being developed. Goal: Create a program for visualizing and analyzing data from 137 Cs calibration runs of HCAL. Create a program for visualizing and analyzing data from 137 Cs calibration runs of HCAL. Short term objectives: user-friendly interface; user-friendly interface; visualization of parameters in each row and tile of each cell; visualization of parameters in each row and tile of each cell; visualization of average parameters for each row; visualization of average parameters for each row; time dependence of parameters. time dependence of parameters.

3. HCAL calibration system Six stainless steel pipes pass through the centers of each tile row (27m per module). All modules of each half calorimeter are connected. A ~ 10 mCi 137 Cs source is used. The source moves at constant speed (~ 30 cm/s). Dependence of current on time I(t) is fitted with a weighted sum of (empirically obtained) tile response functions placed at equal time intervals. Fit results are saved in ASCII files. 3 calibration system working principle typical view of the response function for one row Each peak corresponds to one tile

4. Software development is carried out in C++ under Linux. Standalone package depending on ROOT v5.34/36 libraries. Standard compiler GNU C/C++ v5.3. 4 Algorithm Initialization: create histograms, arrays, GUI elements; create histograms, arrays, GUI elements; read list of directories with calibration data from configuration file; read list of directories with calibration data from configuration file; read fit results from ASCII files of all runs, store the data in arrays. read fit results from ASCII files of all runs, store the data in arrays. Average values and sorting: sort calibration runs by time (dd/mm/yy); sort calibration runs by time (dd/mm/yy); average values over rows of calorimeter cells. average values over rows of calorimeter cells. Filling histograms: fill 2D histograms for selected run. fill 2D histograms for selected run. Data transfer to GUI: transform cells coordinates from (x, y, z) to (module, cell, zone); transform cells coordinates from (x, y, z) to (module, cell, zone); handle events generated by interface elements, visualize chosen calibration parameters; handle events generated by interface elements, visualize chosen calibration parameters; handle mouse menu plot parameters vs time. handle mouse menu plot parameters vs time. block diagram of the program algorithm choose calibration run initialization average values, sort runs by time fill histograms data transfer to interface (GUI) refill histograms to save memory

5. Calibration data visualization 5 (distribution of average amplitudes in scintillator tiles is shown) Interface elements of main menu Calorimeter cells Title including parameter name Date and time of calibration run LHC pipe Parameter values Program interface is a 2D map of HCAL with X and Y axes showing geometrical coordinates of calorimeter cell. Z axis corresponds to value of visualized parameter.

6. Interface functionality 6 Histogram date and name, direction of the 137 Cs source. Mouse coordinates. Histograms switcher for parameters depending on row or tile. HCAL zone; cell coordinate on X axis; cell coordinate on Y axis. From left to right: average value or value in each row; scintillator tile (for amplitude distributions); name of parameter for visualization; calibration run date; direction of 137 Cs capsule. user menu Main menu functionality: 1)choice of parameter for visualization: HV, integrator calibration coefficient, pedestal, average tile amplitude, fit parameters, velocity, begin and end time of source crossing of tile row. HV, integrator calibration coefficient, pedestal, average tile amplitude, fit parameters, velocity, begin and end time of source crossing of tile row. 1)plot average value of chosen parameter over each row; 2)plot amplitude distribution in each scintillator tile; 3)choice of direction of movement of calibration source (F – forward и R – reverse); 4)choice of calibration run by date.

7. Configuration of input directories 7 Paths to the 137 Cs calibration data are read from a text configuration file at GUI startup. A script written in bash shell lets user quickly build the configuration file. To rebuild configuration file either type: ‘or ‘ To rebuild configuration file either type: ‘ formpaths.sh’ or ‘ make paths’, and/or edit the configuration file by hand ( and/or edit the configuration file paths.txt by hand ) example of paths.txt file execution of command in terminal Execution command Added paths

8. Visualization for each row and tile 8 Software functionality allow visualization histograms for each row and tile. tile selection menu row selection menu example of amplitude distribution in tile № 5, row № 3 example of fit parameter distribution in row № 2

9. Possible applications 9 1) distribution of fit quality parameter value allows to evaluate the quality of the fit to response functions; 2) empty cells indicate that the PMT is out of order, or optical contact between WLS-fibers and PMT is lost. distribution of average fit quality parameter 2 1 response function fit by analysis software bad fit Example: known issue probably due to pipe defect during channel manufacturing. Source slowdown in cell A05 row 1.

10. extended context menu points taken at different HV settings (runs labeled 36, 30 and 20 GeV) history plot for tile amplitude for selected cell History plots 10 The software allows user to monitor changes of calibration parameters over time. Mouse menu was extended with additional items to build history plots of calibration values. Right mouse click on a cell lets user to build 4 different plots for currently visualized calibration parameter: history for selected cell, inner zone, outer zone, all HCAL. Average amplitude

11. Complete cell information 11 full information about selected cell Left mouse click on a cell in HCAL map prints out a dump of complete information about selected cell for both 137 Cs source movement directions. F- direction R - direction

12. Conclusion 12 Next steps to expand the possibilities of the software: upload project to LHCb Git repository; upload project to LHCb Git repository; code polishing, OOP refactoring necessary to simplify future development; code polishing, OOP refactoring necessary to simplify future development; perform calibration itself: calculate deviations of average currents from the nominal ones (aka calibration coefficients) and new HV values perform calibration itself: calculate deviations of average currents from the nominal ones (aka calibration coefficients) and new HV values for multipass calibration runs (HV scans) calculate parameters of PMT regulation curves. for multipass calibration runs (HV scans) calculate parameters of PMT regulation curves. visualize results of calibration (regulation curves parameters, new HV etc) ; visualize results of calibration (regulation curves parameters, new HV etc) ; «raw» data processing directly from the GUI; «raw» data processing directly from the GUI; various historical plots (e.g., light yield degradation); various historical plots (e.g., light yield degradation); GUI for visualization of data from 137 Cs calibration runs of LHCb HCAL has been developed. GUI for visualization of data from 137 Cs calibration runs of LHCb HCAL has been developed. Beta version of the software is already in use! Beta version of the software is already in use!

13. 13 Thank you for attention!