BEAMBEAM (updated May 3, 2005)
The main program and sample initialization files are in "/home/dlr/development1_linux/beambeam".
  • Description: Generate a gaussian distribution in 3 dimensional phase space of N_part particles and track them for N_turn turns. Tune the model by interactively changing parameters. Strong beam size is updated to be consistent with weak beam size.
  • The parameters of the scan are given in an input file. An example of an input file is "/home/dlr/development1_linux/beambeam/beambeam.in"
    • Input file beambeam.in 
      & parameters                                                                     
    Q_x =   0.51500   !horizontal tune with lrbbi included
    Q_y =   0.61500   !vertical tune with lrbbi included
    Q_z  = -0.1       !synchrotron tune                                                          
    Q_x_init = 0.55   !safe horizontal tune where lrbbi and beambeam are added. This is only for setup
    Q_y_init = 0.59   !safe vertical tune where lrbbi and beambeam are added. This is only for setup
    lat_file = '/home/dlr/bmad_allocate2/bmad/lat/low_emitt_ew_sym_20040503.lat_and_layout_symp_map'
    n_turn = 100000
    particle = 1      ! 1=positrons, -1=electrons                                                        
    n_part = 100      ! number of particles in distribution
    i_train = 1       !train of tracked bunch                                                          
    j_car = 1         !car of tracked bunch                                                          
    n_trains_tot = 9  !number of trains in strong beam                                                  
    n_cars = 4        !number of cars in strong beam
    current = 0.5     !bunch current in strong beam
    lrbbi = .true.    !if true, include long range parasitic interactions
    beambeam_ip = .true.  !if true, include beam beam interaction
    close_pretz = .true.  !if true, adjust horizontal separators 8e, 8w to ensure collisions
    close_vert = .true.   !if true, adjust vertical separator, and vnoseing 1 to ensure collisions
    rec_taylor = .true. !if true look for digested file appropriate to your choice of bunch pattern
                             and copy taylor coefficients to active ring. This feature is only useful
                             if taylor coefficients exist. 
    slices = 5          !Beambeam interaction treated as  longitudinal kicks. (Default = 1)
    go = .true.  !if true, then no interactive input. If false, interactively adjust ring parameters.
                             At prompt "GO>" type "?" to see options. Or input from file
    min_sig = 0  !Only use particles with x+y+z > min_sig.
    coupling_sb = 0.01 !coupling assumed to generated strong beam parameters
    coupling_wb = 0.01 !coupling assumed to generate weak beam distribution
    radiation   = .true. !if true include radiation damping and fluctuations
    rec_taylor = .true. !if true look for digested file appropriate to your choice of bunch pattern
                             and copy taylor coefficients to active ring. This feature is only useful
                             if taylor coefficients exist.                            
    fit        = sig
    final_pos_in = 0. 0. 0. 0. !designated x,x',y,y' weak strong beam separation at IP
    parallel = .false.
/
      Parallel processing

      More physics of simulation

      Mike's feynmann fix 4/2007