CEA Codes forum

Hi

Yes, the variable VFAC is made for that purpose. By default, it is equal to 1. Also, it is to you to write a script for producing a sequence of .inp files with changing VFAC and run the code.

Please note that, at the moment, you decrease the voltage, obviously, the transmission will decrease also, at some point, there won't be anymore particles with an energy close the reference. This may cause the code to end abruptly depending how you play with the energy filter.

I hope it helps.

Romuald DUPERRIER

script means writing a batch file for various vfac settings...please see if you may give any example for it.

Thanks

Sarvesh

I do not have any example script for a varying vfac. I am sorry. But basically, your script has to build a new .inp with a copy of an orginal .inp until the command vfac to be adjusted, then add a new line with "end". Finally run 'toutatis.exe -i new.inp -nox" and gets results in toutatis.out to be saved at your convenience.

Best

Romuald

Dear Romuald

From RFQdesign, I have got an optimum solution for 3 MeV RFQ, 4 m RFQ, 70 mA with 0.15 mm-mrad as input emit in generated file for Toutatis. I have to increase input emit. 0.5 mm-mrad, What I should do ? Please give a general advice. Which parameter to be adjusted in .rfqd file. Secondly why beta x and Y are very high in generated file for Toutatis? How to find matched alpha and betas for an optimum solution from RFQdesign code. I can share file with you if you wish to see it in details. Please help me.

Thanks
Sarvesh

Hi,

If you want to increase the transverse acceptance of your RFQ for a given particle, you can increase the voltage and/or the wavelength.

For getting matched Twiss parameters and if you do not have Toutatis, RFQDesigner can only try to find Twiss parameters in envelop mode but this does not work as well as mutliparticle matching. If you have Toutatis, check the box "Multiparticle matching" and ensure that a proper path to Toutatis is declared just below.

Best,


Romuald

Thanks Romuald, Can you please give the mathematical expression for all parameters used in the RFQdesign code, any physics manual or report so that we can match handson calculations with initial guess to be put in RFQdesign.

Physics of RFQ Designer is in section 6.2 of the attached doc.

Best,

Romuald

Any specific reference on how to design radial matching section using RFQDesign ?

If we give beam.dst file in Toutatis and also by command line input -6 100000 ..........
then from where the toutatis will take alphas and betas and emittances finally....

.dst file will prevail.

R