Difference between revisions of "SHMS Single arm Monte Carlo"

Revision as of 16:58, 2 November 2012

Source code

• mc_shms_single_april2012.tar.gz is the tarball. Discussion of the changes made to code.
• On JLab ifarm64 machines execute : "setup cernlib/2005" before doing "make"

Comments on code

• Designed to be used for studying optics and acceptance of the SHMS.
• Materials hit when multiple scattering flag turned on.
  • Target
    • When target length greater than 3cm, assumes a beer can target with diameter of 3.37cm and wall thickness of 0.005 inches
    • Need to enter the radiation length of target material in the input file.
  • Scattering chamber window is 0.016inches of aluminum
  • 15 cm of air between scattering chamber and snout. Since snout is not designed this is a guess.
  • SHMS entrance window is 0.020 inches of aluminum.
  • SHMS exit window is 0.020 inches of aluminum.
  • Three options for after the SHMS exit window
    • Argon/Neon Cerenkov. Set the cer_flag=1 ( line 22 in input file). The vac_flag ( line 23 in input file) is ignored.
    • Helium bag replaces the Argon/Neon Cerenkov. This is the assumed mode of option at low momentum. Set the cer_flag=0 ( line 22 in input file) and set the vac_flag=0 ( line 23 in input file).
    • For study, vacuum pipe replaces the Argon/Neon Cerenkov. Set the cer_flag=0 ( line 22 in input file) and set the vac_flag=1 ( line 23 in input file).
  • SHMS wire chambers
• SHMS wire chamber resolution is 200 microns
• SHMS collimator is in place and cuts events.
• Events cut if outside area of drift chambers, S1 and S2 scintillators and the calorimeter in mc_shms_hut.f.
• Dipole apertures used in the MC model: The following figures describe how to calculate the parameters required to describe the dipole apertures in the MC. The dipole effective length is divided into 8 equal segments and the aperture center and inclinations are calculated at each of these segments. The inclinations angles are shown in angles, and the drift distances and offsets of the center of the aperture with respect to the central trajectory are shown in table of offsets (20 cm drop) and (26 cm drop)