The OPAL Discussion Forum

[Philippe Piot <philippe.piot AT gmail.com>]

Dear All,

  I am trying to understand how does the emission work in OPAL Specifically, in my simulation, I emit a Gaussian beam from a cathode with:

    DistFT: DISTRIBUTION, TYPE = GAUSS,
   SIGMAX  = 0.002,
   SIGMAY  = 0.002,
   SIGMAT  = 3.4e-12,
            EMISSIONSTEPS = 500,
   CUTOFFLONG = 3,
   CUTOFFX = 0.5,
   CUTOFFY = 0.5, // CUTOFFR is not implemented/wotking?
            EMITTED = True,        
            EMISSIONMODEL = ASTRA,
            EKIN = 0.55,      
//    NBIN=5,
            WRITETOFILE = True;

   What surprises me is that as I increase the charge I should see the onset of space-charge-induced saturation and not all the particle being emitted anymore. But OPAL does emit all the particles -- ultimately the distribution is extremely disrupted (but not as one would expect from space charge). Am I doing anything wrong above?  

  Also, I noticed, independently of charge (or even with FC_solver=None) I get a warning:

OPAL{0}> *****************************************************

OPAL{0}> Warning: attempted to rebin, but not all distribution
OPAL{0}> particles have been emitted. Rebin failed.
OPAL{0}> *****************************************************
OPAL{0}> *****************************************************
OPAL{0}> Warning: attempted to rebin, but not all distribution
OPAL{0}> particles have been emitted. Rebin failed.
OPAL{0}> *****************************************************

   Thank you,  -- Philippe.