The OPAL Discussion Forum

[Ezgi Sunar <ezgi.sunar AT mnt.com.tr>]

Dear Sir/Madam,

 

I am working on the design of a low energy cyclotron (for industrial applications).

The first result I’d like to get is a simple tune calculation in order to optimise the magnetic field

To achieve this, I have modified the cyclotron example file from the OPAL wiki page to suit my design parameters. Here is the relevant section of the input file:

 

Name_Cycl: CYCLOTRON, TYPE=CARBONCYCL, CYHARMON=4, FMLOWE=0.5, FMHIGHE=3.0, PHIINIT=0.0, PRINIT=pr0, RINIT=r0, SYMMETRY=4.0, RFFREQ=f1, FMAPFN="bfield.dat", BSCALE=1E-3;

L1: LINE = (Name_Cycl);

Dist1: DISTRIBUTION, TYPE=FILENAME, NSTEPS=100, SECTOR=FALSE, FNAME="dist1.dat";

Fs1: FIELDSOLVER, FSTYPE=NONE, MX=64, MY=64, MT=64, PARFFTX=true, PARFFTY=true, PARFFTT=false, BCFFTX=open, BCFFTY=open, BCFFTT=open;

Beam1: BEAM, PARTICLE=PROTON, PC=P0, NPART=2, BCURRENT=1.0E-6, BFREQ=f1;

SELECT, LINE=L1;

TRACK, LINE=L1, BEAM=Beam1, MAXSTEPS=nstep*turns, STEPSPERTURN=nstep;

RUN, METHOD="CYCLOTRON-T", BEAM=Beam1, FIELDSOLVER=Fs1, DISTRIBUTION=Dist1;

 

As part of the tune calculation mode, I am using data distribution for two particles: one as the reference particle with all data set to zero and another one off-center. The `dist1.dat` file includes the following information:

 

2

0.0         0.0           0.0           0.0          0.0           0.00

0.005       0.001         0.005         0.001        0.005         0.001

 

Additionally, the B-field data is created with:

- Grid points along azimuth (ntet): 239

- Grid points along radius (nrad): 4

 

4

4

0.0

1.5

239

48

11296.6  11317.7  11327.6  11337.9  11354.2

11367.0  11378.0  11393.0  11412.4  11435.4

11453.5  11472.2  11495.2  11523.0  11551.7 ......

 

Upon running this configuration, I encountered a few issues and a failure during execution. I would appreciate your guidance on the following points:

 

1. How and where can I define the initial and final energies in the input file?

2. Which type of cyclotron should I run for this application? I suppose it would be CARBONCYCL. If so, I have some difficulties with the necessary structures of the data files; like BFIELD.

3. How and where can I define and calculate the orbit coordinates according to the given energies in the input file? I found that OPAL uses the external program FIXPO for calculating the initial orbit coordinates based on our desired energy range. If this is correct, I cannot find how and where to set these parameters.

 

I have attached the error message encountered during the run for your reference.

 

Thank you for your assistance.

 

Best regards, 

Ezgi Sunar