Difference between revisions of "Start Counter Background Studies"
From GlueXWiki
(Created page with "* Seema and Sasha's Old Background Study: [https://halldweb1.jlab.org/talks/2012-2Q/background/SC_simulations.pdf] * Sasha's Howto [https://halldweb1.jlab.org/wiki/index.php/HOWT...") |
m (Text replacement - "/halldweb1.jlab.org/" to "/halldweb.jlab.org/") |
||
(11 intermediate revisions by one other user not shown) | |||
Line 1: | Line 1: | ||
− | * Seema and Sasha's Old Background Study: [https:// | + | * Seema and Sasha's Old Background Study: [https://halldweb.jlab.org/talks/2012-2Q/background/SC_simulations.pdf] |
− | * Sasha's Howto [https:// | + | * Sasha's Howto [https://halldweb.jlab.org/wiki/index.php/HOWTO_to_generate_electromagnetic_background] |
− | ===EM Background=== | + | === EM Background Rates === |
− | * Generated | + | * 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'' | ||
− | * Plots | + | '''$ genr8_2_hddm -V"0 0 50 80" file_out.ascii''' |
− | ** Rates [https:// | + | |
− | ** Hit Multiplicity [https:// | + | * Use the following control.in file options to process the events through HDGEANT (from latest sim-recon version) |
− | ** R vs Z hit [https:// | + | ** 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''' |
− | ** Y vs X hit [https:// | + | ** The background rate is set appropriately depending on the threshold: |
+ | *** 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''' (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: | ||
+ | |||
+ | <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, | ||
+ | and <math>N</math> is the number of events generated. | ||
+ | |||
+ | * Plots <math>10^8 \gamma/s</math> | ||
+ | ** Rates [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/paddle_rate_1.png] | ||
+ | ** Hit Multiplicity [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/hitmult_1.png] | ||
+ | ** R vs Z hit [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/rz_1.png] | ||
+ | ** Y vs X hit [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/yx_1.png] | ||
+ | ** Energy [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/energy_1.png] | ||
+ | |||
+ | * Plots <math>10^7 \gamma/s</math> | ||
+ | ** Rates [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/paddle_rate_2.png] | ||
+ | ** Hit Multiplicity [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/hitmult_2.png] | ||
+ | ** R vs Z hit [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/rz_2.png] | ||
+ | ** Y vs X hit [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/yx_2.png] | ||
+ | ** Energy [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/energy_2.png] | ||
+ | |||
+ | === 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'''. <!----The bggen card options are: [https://halldweb.jlab.org/talks/2012-2Q/background/hadronic_bggen_run.ffr]----> | ||
+ | * 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: | ||
+ | ** Rates [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/paddle_rate_1.png] | ||
+ | ** Hit Multiplicity [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/hit_mult_1.png] | ||
+ | ** R vs Z hit [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/rz_1.png] | ||
+ | ** Y vs X hit [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/yx_1.png] | ||
+ | ** Energy [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/energy_1.png] | ||
+ | |||
+ | |||
+ | ====Energy Cuts==== | ||
+ | * E > 0.2 MeV | ||
+ | ** EM only [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/paddle_rate_0.2mev.png] | ||
+ | ** Hadronic [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/paddle_rate_0.2mev.png] | ||
+ | * E > 0.3 MeV | ||
+ | ** EM only [https://halldweb.jlab.org/talks/2012-3Q/sc_background/em/paddle_rate_0.3mev.png] | ||
+ | ** Hadronic [https://halldweb.jlab.org/talks/2012-3Q/sc_background/had/paddle_rate_0.3mev.png] | ||
+ | |||
+ | |||
+ | |||
+ | ------ | ||
+ | |||
+ | * [[Main Page|GlueX Wiki]] » [[Start Counter]] » [[Start Counter Background Studies]] |
Latest revision as of 21:54, 31 March 2015
EM Background Rates
- 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:
Energy Cuts
- GlueX Wiki » Start Counter » Start Counter Background Studies