atsetRFCavity

  ATSETRFCAVITY sets the RF Cavity with the passmethod RFCavityPass.
  RFCavityPass allows to change the energy of the beam changing the
  frequency of the cavity.

   newring = atSetRFCavity(ring, rfv, radflag, HarmNumber, DeltaFreq)
   sets the synchronous phase of the cavity, the voltage, the harmonic
   number and the PassMethod. All the N cavities will have a voltage rfv/N
   radflag says whether or not we want radiation on, which affects
   synchronous phase. If radflag is 0, the function calls atradoff, if it
   is 1, it calls atradon.
   Cavities in the ring must have the Class RFCavity.
   Normally DeltaFreq should be 0, it's different from 0 when you want to
   simulate a change of energy changing the RF frequency. DeltaFreq is in
   Hz.

   normal use:
   newring = atsetRFCavity( ring, 6e6, 1, 992, 0 )
   for off-energy simulations:
   newring = atsetRFCavity( ring, 6e6, 1, 992, 100 )

   see also: atsetcavity

0001 function newring = atsetRFCavity( ring, rfv, radflag, HarmNumber, DeltaFreq )
0002 %  ATSETRFCAVITY sets the RF Cavity with the passmethod RFCavityPass.
0003 %  RFCavityPass allows to change the energy of the beam changing the
0004 %  frequency of the cavity.
0005 %
0006 %   newring = atSetRFCavity(ring, rfv, radflag, HarmNumber, DeltaFreq)
0007 %   sets the synchronous phase of the cavity, the voltage, the harmonic
0008 %   number and the PassMethod. All the N cavities will have a voltage rfv/N
0009 %   radflag says whether or not we want radiation on, which affects
0010 %   synchronous phase. If radflag is 0, the function calls atradoff, if it
0011 %   is 1, it calls atradon.
0012 %   Cavities in the ring must have the Class RFCavity.
0013 %   Normally DeltaFreq should be 0, it's different from 0 when you want to
0014 %   simulate a change of energy changing the RF frequency. DeltaFreq is in
0015 %   Hz.
0016 %
0017 %   normal use:
0018 %   newring = atsetRFCavity( ring, 6e6, 1, 992, 0 )
0019 %   for off-energy simulations:
0020 %   newring = atsetRFCavity( ring, 6e6, 1, 992, 100 )
0021 %
0022 %   see also: atsetcavity
0023 
0024 clight=299792458 ;
0025 
0026 newring = ring;
0027 indrfc=findcells(ring,'Class','RFCavity');
0028 beta0=1;
0029 U0=atgetU0(ring); %% not ok if misaligned elem!
0030 
0031 circ=findspos(ring,length(ring)+1);
0032 
0033 newring=setcellstruct(newring,'PassMethod',indrfc,'RFCavityPass');
0034 
0035 freq0=(clight*beta0/circ)*HarmNumber;
0036 
0037 freq=freq0+DeltaFreq;
0038 
0039 %now set cavity frequencies, Harmonic Number and RF Voltage
0040 for j=indrfc
0041     newring{j}.Frequency=freq;
0042     newring{j}.HarmNumber=HarmNumber;
0043     newring{j}.Voltage=rfv/length(indrfc);
0044 end
0045 
0046 %now set phaselags in cavities
0047 if radflag
0048     timelag= (circ/(2*pi*HarmNumber))*asin(U0/(rfv));
0049     newring=atradon(newring,'RFCavityPass','auto','auto');  % set radiation on. nothing if radiation is already on
0050     newring=setcellstruct(newring,'PassMethod',indrfc,'RFCavityPass');
0051 else
0052     newring=atradoff(newring,'RFCavityPass','auto','auto');  % set radiation off. nothing if radiation is already off
0053     newring=setcellstruct(newring,'PassMethod',indrfc,'RFCavityPass');
0054     timelag=0;
0055 end
0056 newring=setcellstruct(newring,'TimeLag',indrfc,timelag);
0057 end