Difference between revisions of "Modeling"

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=='''How To Get It'''==
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The Mott Group has a GEANT4 simulation of the JLab MeV Mott Polarimeter. This simulation was built from 2014-2016 simultaneous to the upgrade efforts on the polarimeter. The primary purpose of this simulation is to determine, from first principles, the shape of the effective Sherman function with respect to target thickness. This page serves a few purposes: it provides links to the relevant references for simulation users, provides a brief tutorial, and shows results. Additionally, this page may serve as a place to indicate what work is being done or needs to be done on the simulation.  
*User must set environment variable '''$MOTTG4DIR''' to '''/path/to/MottG4/''' before using the simulation.
 
*A working version is maintained on the '''ifarm''' computers CUE in the directory '''/group/mottgrp/MottG4'''
 
*The current version is maintained at [https://github.com/mjmchugh/MottG4 github] for those who want the model on their personal computers. Contact Martin McHugh at mjmchugh@jlab.org for access to this repository.
 
  
=='''How It Works'''==
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=='''Where To Find the Simulation'''==
*The Mott Polarimeter team is developing a [http://geant4.cern.ch/ GEANT4] model of the polarimeter.
 
  
=='''To Do List'''==
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*A working version is maintained on the '''ifarm''' computers CUE in the directory '''/group/mottgrp/MottG4/'''.
*<s>Add pre-vertex energy loss</s> Small effect for our targets (~50 keV max in 5 um Au) according to [http://physics.nist.gov/PhysRefData/Star/Text/ESTAR.html NIST] --[[User:Mjmchugh|Mjmchugh]] ([[User talk:Mjmchugh|talk]]) 17:54, 22 April 2015 (EDT)
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*To use this, the user must set the environment variable '''$MOTTG4DIR''' to '''/path/to/MottG4/''' before using the simulation.
*<s>Add primary vertex output info:
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*Additionally, the user must have access to '''cmake''' version 2.8 or later.  
**Scattering cross-section
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*The current version is maintained at [https://github.com/JLabMottGroup/MottG4 github] for those who want the model on their personal computers or some other location for development purposes. Contact Martin McHugh at mjmchugh@jlab.org for access to this repository.
**Scattering location 3-vector
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**Outgoing polarization 3-vector</s> --[[User:Mjmchugh|Mjmchugh]] ([[User talk:Mjmchugh|talk]]) 19:04, 9 June 2015 (EDT)
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=='''Documentation'''==
*Integrate Xavier's most recent calculations.
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The best way to get started is to read the Tutorial slides.
*<s>Interactively change angular range for primaries</s> --[[User:Mjmchugh|Mjmchugh]] ([[User talk:Mjmchugh|talk]]) 09:57, 16 June 2015 (EDT)
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*<s>Change Random Seed handling to GEANT4 standard a la QweakSimG4.</s> --[[User:Mjmchugh|Mjmchugh]] ([[User talk:Mjmchugh|talk]]) 15:36, 29 June 2015 (EDT)
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[[File:MottGeant4Tutorial.pdf]]
*Build Mott Physics Class (single scattering based on Xavier's data).
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*<s>Build Double-Scattering Generator</s> --[[User:Mjmchugh|Mjmchugh]] ([[User talk:Mjmchugh|talk]]) 15:35, 29 June 2015 (EDT)
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[[May 10th Simulation Tutorial BlueJeans Information]]
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 +
Herein lies all that Marty McHugh has written about the Mott GEANT4 simulation:
 +
 
 +
*[[Media:PSTPFinal.pdf]]: PSTP 2013 Presentation
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*[http://pos.sissa.it/archive/conferences/182/040/PSTP2013_040.pdf PSTP 2013 Proceedings]
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*[[Media:DNP_Final.pdf]]: DNP Fall 2013 Meeting Presentation
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*[[Media:Mott_Geant4_User_Guide.pdf]]: User's guide
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*Tech Note
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*[[List of meeting talks]]
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 +
External sources of interest:
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*[http://geant4.cern.ch/ GEANT4 Documentation]
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*[https://git-scm.com/docs/gittutorial Git Tutorial]
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*[http://scicomp.jlab.org/scicomp/ Jefferson Lab Scientific Computing]
 +
 
 +
=='''Future Work: A Suggested To Do List'''==
 +
*'''Double Check Marty''' We're no longer a team of one!
 +
*Compare simulated spectra to real spectra
 +
*Get Xavier's calculations for gold and other nuclei of interest on a 100-250 keV over the whole range of energies (approx. 2-10 MeV)
 +
**Integrate this into the exiting interpolation method in '''MottPrimaryGeneratorAction.cc'''.
 +
**Perform calculations for target foil thickness extrapolation based on final Run 2 parameters:
 +
*** Scattering Angle
 +
*** KE = 4.9 MeV.
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*** Final thickness measurments from Marcy.
 +
*Build Mott Physics Class (single scattering based on Xavier's data). (Low priority)
 +
 
 +
=='''FAQ'''==
 +
*Rejection method -- gets you asymmetries; vs rate method -- gets you rates

Latest revision as of 17:07, 25 August 2016

The Mott Group has a GEANT4 simulation of the JLab MeV Mott Polarimeter. This simulation was built from 2014-2016 simultaneous to the upgrade efforts on the polarimeter. The primary purpose of this simulation is to determine, from first principles, the shape of the effective Sherman function with respect to target thickness. This page serves a few purposes: it provides links to the relevant references for simulation users, provides a brief tutorial, and shows results. Additionally, this page may serve as a place to indicate what work is being done or needs to be done on the simulation.

Where To Find the Simulation

  • A working version is maintained on the ifarm computers CUE in the directory /group/mottgrp/MottG4/.
  • To use this, the user must set the environment variable $MOTTG4DIR to /path/to/MottG4/ before using the simulation.
  • Additionally, the user must have access to cmake version 2.8 or later.
  • The current version is maintained at github for those who want the model on their personal computers or some other location for development purposes. Contact Martin McHugh at mjmchugh@jlab.org for access to this repository.

Documentation

The best way to get started is to read the Tutorial slides.

File:MottGeant4Tutorial.pdf

May 10th Simulation Tutorial BlueJeans Information

Herein lies all that Marty McHugh has written about the Mott GEANT4 simulation:

External sources of interest:

Future Work: A Suggested To Do List

  • Double Check Marty We're no longer a team of one!
  • Compare simulated spectra to real spectra
  • Get Xavier's calculations for gold and other nuclei of interest on a 100-250 keV over the whole range of energies (approx. 2-10 MeV)
    • Integrate this into the exiting interpolation method in MottPrimaryGeneratorAction.cc.
    • Perform calculations for target foil thickness extrapolation based on final Run 2 parameters:
      • Scattering Angle
      • KE = 4.9 MeV.
      • Final thickness measurments from Marcy.
  • Build Mott Physics Class (single scattering based on Xavier's data). (Low priority)

FAQ

  • Rejection method -- gets you asymmetries; vs rate method -- gets you rates