Difference between revisions of "Wednesday, July 11, 2012"

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* don't have to worry about overlapping with scoring mesh?
 
* don't have to worry about overlapping with scoring mesh?
 
*  
 
*  
−
<br><br>
+
<br>
  
  
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* layer to read step files in directly is abandoned
 
* layer to read step files in directly is abandoned
 
* child gdml files are not assembly volumes - the development for adding assembly volumes is "frozen"
 
* child gdml files are not assembly volumes - the development for adding assembly volumes is "frozen"
−
<br><br>
+
<br>
  
  
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*   
 
*   
 
*
 
*
 +
<br>
 +
=== EM Physics II ===
 +
 +
* Livermore Physics
 +
** have some process classes, but model classes are different
 +
* Polarized Livermore models
 +
* Penelope models
 +
<br>
 +
 +
=== Hadronic Physics I ===
 +
 +
* models need to cover the whole energy range that you want
 +
* only defaults in hadronic physics are for cross-section sets
 +
* quark-gluon string - QGSP
 +
* slide 10 - LEP, HEP, old GEISHA code, translated from FORTRAN to C++
 +
* slide 11 - partial inventory of available physics lists
 +
* can't have a model with an energy range fully covered by another model
 +
 +
* slide 14 explanation
 +
** top-left
 +
*** high energy hadron coming into a nucleus
 +
*** excite nucleons in a relatively small cylinder around the track - quark cascade
 +
*** hadron can interact in nucleus, and particles are QM entangled
 +
*** secondaries don't form until outside nucleus
 +
*** covered by QGS, FPF
 +
 +
** top-right
 +
*** within nucleus, nucleon interactions - intranuclear cascade
 +
 +
** lower-left
 +
*** highly excited nucleus
 +
*** exciton models are used
 +
 +
** lower-right
 +
*** de-excitation stage
 +
*** nucleus at equilibrium - evaporating photons and neutrons
 +
*** HP models are starting to be used
 +
 +
* Specific Models
 +
** Elastic scattering
 +
*** valid for all energies
 +
** coherent elastic
 +
*** sees nucleus as a whole
 +
** neutron elastic from HP models
 +
 +
* Validation
 +
** G4HadronElastic - not valid above about 20 degrees (need coherent model)
 +
** Low energy neutron physics data-driven - large database
 +
*** if thermal is important, need to download add'l DB
 +
*** G4NDL - update to 4.9.5 - big step in quality of HP data
 +
*** multiple DB with different formats
 +
*** now we know it all comes from ENDF/B-VII DB w/ format
 +
*** small energy non-conservation because data is binned
 +
** Inelastic neutron
 +
*** pretty good for something that fed the DB (interpolation of data)
 +
** Neutron capture
 +
 +
* If you don't have an isotope, what does G4 do?
 +
** uses LEP - old GEISHA model automatically
 +
** does tell you what it is doing
 +
 +
* even if you don't need thermal - 4.0 or later - should get them
 +
 +
* QMD is better than binary cascade when compared to data (nuclear fragments)
 +
** takes a long time
 +
** slide 37 - instructions to include it in your physics list
 +
 
<br><br>
 
<br><br>
 +
 +
  
 
== Afternoon Talks ==
 
== Afternoon Talks ==
 +
 +
=== Hadronic Physics II ===
 +
 +
*
 +
*
 +
<br>
 +
 +
=== Hadronic Physics III ===
 +
 +
*
 +
*
 +
<br>
 +
 +
=== Analysis ===
 +
 +
*
 +
*
 +
<br>
 +
 +
=== Hands On III ===
 +
 +
*
 +
*
 +
  
  

Latest revision as of 11:54, 11 July 2012

Morning Talks

Scoring I

  • score energy deposition, for example, on the surface of a volume
  • don't have to worry about overlapping with scoring mesh?



Geometry III - GDML and CAD

  • use if you want to make changes without having to rebuild
  • can do ALMOST everything that you can with the GDML geometry
  • defining "dummy" materials and then using hard-coded def'ns is the way to do it (pending reply of

an expert)

  • slide 22 - links to forum and tech note for GDML
  • cadmesh - can get tesselated solid from CAD but can't go from G4 to CAD
  • layer to read step files in directly is abandoned
  • child gdml files are not assembly volumes - the development for adding assembly volumes is "frozen"



User Interface II

Could use notes for this


EM Physics II

  • Livermore Physics
    • have some process classes, but model classes are different
  • Polarized Livermore models
  • Penelope models


Hadronic Physics I

  • models need to cover the whole energy range that you want
  • only defaults in hadronic physics are for cross-section sets
  • quark-gluon string - QGSP
  • slide 10 - LEP, HEP, old GEISHA code, translated from FORTRAN to C++
  • slide 11 - partial inventory of available physics lists
  • can't have a model with an energy range fully covered by another model
  • slide 14 explanation
    • top-left
      • high energy hadron coming into a nucleus
      • excite nucleons in a relatively small cylinder around the track - quark cascade
      • hadron can interact in nucleus, and particles are QM entangled
      • secondaries don't form until outside nucleus
      • covered by QGS, FPF
    • top-right
      • within nucleus, nucleon interactions - intranuclear cascade
    • lower-left
      • highly excited nucleus
      • exciton models are used
    • lower-right
      • de-excitation stage
      • nucleus at equilibrium - evaporating photons and neutrons
      • HP models are starting to be used
  • Specific Models
    • Elastic scattering
      • valid for all energies
    • coherent elastic
      • sees nucleus as a whole
    • neutron elastic from HP models
  • Validation
    • G4HadronElastic - not valid above about 20 degrees (need coherent model)
    • Low energy neutron physics data-driven - large database
      • if thermal is important, need to download add'l DB
      • G4NDL - update to 4.9.5 - big step in quality of HP data
      • multiple DB with different formats
      • now we know it all comes from ENDF/B-VII DB w/ format
      • small energy non-conservation because data is binned
    • Inelastic neutron
      • pretty good for something that fed the DB (interpolation of data)
    • Neutron capture
  • If you don't have an isotope, what does G4 do?
    • uses LEP - old GEISHA model automatically
    • does tell you what it is doing
  • even if you don't need thermal - 4.0 or later - should get them
  • QMD is better than binary cascade when compared to data (nuclear fragments)
    • takes a long time
    • slide 37 - instructions to include it in your physics list




Afternoon Talks

Hadronic Physics II


Hadronic Physics III


Analysis


Hands On III




Return to JLAB GEANT4 Workshop, July 9-13, 2012
Return to MOLLER GEANT4 Simulations
Return to MOLLER at 11 GeV E09-005

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