Difference between revisions of "Start Counter Background Studies"
From GlueXWiki
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** The energy threshold in for hits in SC is 150 MeV | ** The energy threshold in for hits in SC is 150 MeV | ||
** The time window for two hit resolution is 25 ns | ** The time window for two hit resolution is 25 ns | ||
− | * The hits are then smeared using mcsmear | + | * The hits are then smeared using mcsmear (???) |
+ | |||
+ | * To obtain the appropriate scaling factor for the plots, use the following approach: | ||
+ | |||
+ | <math>f = 1/(2.2*\delta t)/N</math> | ||
+ | |||
+ | 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. | ||
+ | |||
+ | The 2.2 is the BGRATE scale applied to generate 2.2 GHz photons/s. | ||
+ | |||
* Plots | * Plots | ||
** Rates [https://halldweb1.jlab.org/talks/2012-2Q/background/em_paddle_1.png] | ** Rates [https://halldweb1.jlab.org/talks/2012-2Q/background/em_paddle_1.png] | ||
Line 30: | Line 40: | ||
** R vs Z hit [https://halldweb1.jlab.org/talks/2012-2Q/background/em_rz_1.png] | ** R vs Z hit [https://halldweb1.jlab.org/talks/2012-2Q/background/em_rz_1.png] | ||
** Y vs X hit [https://halldweb1.jlab.org/talks/2012-2Q/background/em_yx_1.png] | ** Y vs X hit [https://halldweb1.jlab.org/talks/2012-2Q/background/em_yx_1.png] | ||
+ | |||
+ | |||
+ | |||
+ | ------ | ||
+ | |||
+ | * [[Main Page|GlueX Wiki]] » [[Start Counter]] » [[Start Counter Background Studies]] |
Revision as of 09:56, 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.
The 2.2 is the BGRATE scale applied to generate 2.2 GHz photons/s.
- GlueX Wiki » Start Counter » Start Counter Background Studies