Difference between revisions of "Start Counter Background Studies"
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(→Pure EM Background) |
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* Sasha's Howto [https://halldweb1.jlab.org/wiki/index.php/HOWTO_to_generate_electromagnetic_background] | * Sasha's Howto [https://halldweb1.jlab.org/wiki/index.php/HOWTO_to_generate_electromagnetic_background] | ||
− | === | + | === EM Background === |
* Generated 10K dummy events using | * Generated 10K dummy events using | ||
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** 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 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 is set appropriately depending on the threshold: | ** The background rate is set appropriately depending on the threshold: | ||
− | *** For <math>10^7 \gamma/s</math> use '''BGRATE 1.1''' ( | + | *** For <math>10^7 \gamma/s</math> use '''BGRATE 1.1''' (HDGEANT scales the BGRATE to 2.22) |
− | *** For <math>10^8 \gamma/s</math> use '''BGRATE 11.0''' ( | + | *** For <math>10^8 \gamma/s</math> use '''BGRATE 11.0''' (HDGEANT scales the BGRATE to 22.2) |
** The photon pileup window is set to 100ns: '''BGGATE 0. 100.''' | ** The photon pileup window is set to 100ns: '''BGGATE 0. 100.''' | ||
** The following EM processes are turned on: | ** The following EM processes are turned on: | ||
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** Y vs X hit [https://halldweb1.jlab.org/talks/2012-3Q/sc_background/em/yx_2.png] | ** Y vs X hit [https://halldweb1.jlab.org/talks/2012-3Q/sc_background/em/yx_2.png] | ||
** Energy [https://halldweb1.jlab.org/talks/2012-3Q/sc_background/em/energy_2.png] | ** Energy [https://halldweb1.jlab.org/talks/2012-3Q/sc_background/em/energy_2.png] | ||
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=== Hadronic Rates === | === Hadronic Rates === |
Revision as of 09:27, 26 July 2012
EM Background
- Generated 10K dummy events using
$ genphoton -M 10000 -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 options to process the events through HDGEANT (from latest sim-recon version)
- 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 is set appropriately depending on the threshold:
- For use BGRATE 1.1 (HDGEANT scales the BGRATE to 2.22)
- For use BGRATE 11.0 (HDGEANT scales the BGRATE to 22.2)
- 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 (but is currently not applied in HDGEANT code)
- 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.
Hadronic Rates
- To study the hadronic rates, a similar method is used compared to the EM background study.
- 395K background events are generated using bggen.
- These events are then passed through HDGEANT
- The BGRATE and BGGATE options are turned off as we don't want to look at additional photon pile-up (double counting)
- The same EM processes as above are turned on
- The BEAM options are still BEAM 12. 9. 0.0012
- The output is again smeared using mcsmear
- No normalization factor is applied
- The following rates are observed:
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