Difference between revisions of "Start Counter In Calibration Challenge"

Revision as of 12:26, 23 January 2016

Introduction

Currently, the plugins 1, 2, and 3 are in the sim-recon/src/plugins/Calibration. A summary of how to run each code and the expected outcomes of the macros will be shown in details.

• 1) Start Counter Time Walk Corrections Plugin (st_tw_corr_auto)

• 2) Start Counter Propagation Time Corrections Plugin (ST_Propagation_Time)

• 3) Start Counter Time Resolution Plugin (ST_Tresolution)

• 4) Start Counter Attenuation Corrections Plugin

st_tw_corr_auto

This plugin must run in two passes. In the first pass the parameter USE_TIMEWALK_CORRECTION = 0.Therefore this plugin will generate a ROOT file from an EVIO data file that contains histograms of the time difference (self timing) versus pedestal-subtracted pulse peak amplitude for all 30 start counter sectors. A separate ROOT macro (st_tw_fits.C) will analyze and fit these histograms and provide a table for the CCDB. After uploading the constants into the CCDB, the plugin must run the second pass where USE_TIMEWALK_CORRECTION = 1. The Walk corrected times will be calculated during this pass. The ST self timing resolution is calculated using the macro st_tw_resols.C. In this macro verification plots for each sector is also created.

Plugin Files:

   JEventProcessor_st_tw_corr_auto.cc
   JEventProcessor_st_tw_corr_auto.h

Macros Files:

   st_tw_fits.C
   st_tw_resols.C

To run the plugin, use the following command:

hd_root -PPLUGINS=st_tw_corr_auto /path/to/datafile

To run the first pass macro , use the command :

.x st_tw_fits.C("hd_root.root")

The file st_timewalks.txt will be created with the needed constants for the walk corrections. To upload these constants into the CCDB use the command:

Add timewalk_parms_v2 st_timewalks.txt

After running the plugin for the second time, run the macro st_tw_resols.C using the command

.x st_tw_resols.C("hd_root.root")

ST_Propagation_Time

This plugin must run after we have the walk corrected times from the ST and TOF. The first pass of this plugin will generate a ROOT file from an EVIO data file that contains histograms of the ST propagation time versus Z coordinate of the ST hit location for all 30 start counter sectors. A separate ROOT macro (st_prop_time_v1.C) will analyze and fit these histograms and provide a table for the CCDB through an output text file named (st_prop_time_constants.txt). In order to add these constants to the CCDB use the Command :

Add  propagation_time_corr st_prop_time_constants.txt

To check that these constants work fine run the plugin in the second pass using the command:

hd_root -PPLUGINS=st_tw_corr_auto /path/to/datafile 

Then run the macro st_prop_time_corr_v1.C using the command:

.x st_prop_time_corr_v1.C("hd_root.root")

When the corrected times are calculated use the ST_Tresolution plugin to calculate the ST time resolution.

2) ST_Tresolution