GPT/IBSimu Benchmarking Final Exam

Here are some ideas for a complete benchmarking simulation test between GPT and IBSimu. Both programs will be used to create the same simulation and (ideally) achieve the same results when everything (ionization, field maps, secondary electrons, etc.) are included.

What Should Be Included

Ionization Routine

• Ionization
  • Same ion production rate
  • Same ionization cross section for a given species
  • Same gas density profile (constant for GPT)
• Secondary electrons
  • Same energy distribution (SEDCS in GPT)
  • Secondary electron yield, with Maxwellian energy distribution about 2eV (requires same geometry and model)
• Ions
  • At least H2+ ions (GPT also supports He+ ions)
  • Same energy distribution (Maxwellian about 4eV)

Field Maps

• Photogun E-Field map (Cathode at -130kV, Anode at 0V)
• Solenoid at z=0.76m
• Steering magnets
• Dipole

Initial Distribution

• Same initial distribution (from Cristhian: media:Electrondistribution.txt Columns: x vx y vy z vz iq mass)
  • Or time based? (i.e. flat bunch, single bunch, DC beam, or pulsed beam)

What Results Do We Want

• Same number of ions produced (to within a reasonable margin of error)
• Same energy distributions of ions and secondary electrons
• Same primary electron beam trajectory and profile along the beamline
• Same ion damage pattern at the photocathode (i.e. position, number, and energy distribution at the photocathode)

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