GEANT Simulation Status

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GEANT Simulation Status

• Michael Wood
• University of Massachusetts, Amherst

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Primex GEANT Simulation

• To achieve the 1 result, a realistic detector
  simulation is needed
• Acceptance calculations
• Efficiency studies
• Background investigations
• GEANT simulation can include physical processes
  such as multiple scattering, energy loss, and
  secondary particle productions.
• Primex has software packages primsim and
  psim_digitize as a starting point.

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Primex Simulation Software

• Software philosophy
• primsim generates the initial particles from a
  physical reaction such as
• p0 production or Compton scattering and tracks
  them through the detectors.
• Energy deposition in HYCAL is stored in a bank.
  The output is stored in
• MC banks.
• psim_digitize program to create TDC and ADC
  banks from MC banks.
• Also, detector resolutions are applied. The
  output banks are the raw banks
• which should resemble the banks from a data run.
• prim_ana user analysis code which analyzes raw
  data banks and produces
• reconstruction or physics banks. The program
  should read in either data files
• or the output from psim_digitize.

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Current Status

• In May 2006, we had a meeting to discuss the
  status of the
• simulation software and outline steps to achieve
  our goal of a
• realistic detector simulation.
• Here is some points from the meeting
• Review of the detector volumes and materials in
  place.
• Detailed descriptions of HYCAL, Veto, targets,
  helium bag,
• vacuum box, and PS magnet exist.
• Materials missing are TAC, PS counters, and
  sweeping magnets
• before the target.
• Graphical interface exists to test the
  simulation.
• Built-in generators include p0 production,
  Compton scattering,
• and photon beam.
• Problems exist such as the elasticity from p0
  production is
• unrealistic. Also, the beam incident on the
  target is at a single point
• instead of being distributed over the target
  face.

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Plan for Development

• From the meeting, the plan is to begin testing
  the accuracy of
• simulation package. Dustin with p0 production and
  Yelena with
• Compton scattering have begun to test the
  software.
• The first test will be to produce a geometrical
  acceptance that can
• be believed. At this stage, the focus is on
  primsim.
• Features that are currently be added to primsim
  for debugging
• ffread card standard GEANT3 input to control
  which physics
• processes are ON, which volume are included, and
  which
• thresholds are applied. (M. Wood)
• Expanded MCPART bank currently this bank stores
  the
• generated particle 4-vectors. It will also
  include the 4-vectors of
• the particles before they enter HYCAL. (Y. Prok)

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Summary

• The focus of simulation will be on primsim. The
  psim_digitize code will be left for the future.
• The volume and material descriptions are advanced
  enough to begin testing.
• The goal by the next collaboration meeting will
  be to reproduce a believable geometrical
  acceptance. Dustin and Yelena have started
  testing.
• Small projects exist for a summer student
• Include missing volumes such as PS counters, TAC,
  sweeping magnets.
• Clean up the command line flags and remove
  obsolete features.