Difference between revisions of "Start Counter Background Studies"
From GlueXWiki
Line 28: | Line 28: | ||
* To obtain the appropriate scaling factor for the plots, use the following approach: | * To obtain the appropriate scaling factor for the plots, use the following approach: | ||
− | <math>f = 1/ | + | <math>f = 1/\delta t/N</math> |
where, <math>f</math> is scaling factor, <math>\delta t</math> is the time window (BGGATE) in seconds, | where, <math>f</math> is scaling factor, <math>\delta t</math> is the time window (BGGATE) in seconds, | ||
and <math>N</math> is the number of events generated. | and <math>N</math> is the number of events generated. | ||
− | |||
− | |||
* Plots | * Plots |
Revision as of 10:11, 14 June 2012
Pure EM Background
- Generated 100K dummy events using
$ genphoton -M 100000 -Pmax 0.00001 -Pmin 0.000005 -Thetamin 0. -Thetamax 0.001 -o file_out.ascii
- Convert the ascii events into HDDM format and smear the z-vertex across the entire 30cm long target
NB: This step is not necessary as HDGEANT automatically smears the vertex across all three dimensions
$ genr8_2_hddm -V"0 0 50 80" file_out.ascii
- Use the following control.in file to process the events through HDGEANT (from latest sim-recon version) [3]
- The minimum energy for the photon beam was lowered to 1.2 MeV to look at hits contribution in SC from 50 MeV photons: BEAM 12. 9. 0.0012
- The background rate or flux for this minimum energy is 2.2e9 photons/s: BGRATE 2.2
- The photon pileup window is set to 100ns: BGGATE 0. 100.
- The following EM processes are turned on:
- Compton Scattering: COMP 1
- Pair Production: PAIR 1
- Energy Loss: LOSS 1
- Additional cuts in HDGEANT:
- The energy threshold in for hits in SC is 150 MeV
- The time window for two hit resolution is 25 ns
- The hits are then smeared using mcsmear (???)
- To obtain the appropriate scaling factor for the plots, use the following approach:
where, is scaling factor, is the time window (BGGATE) in seconds, and is the number of events generated.
- GlueX Wiki » Start Counter » Start Counter Background Studies