The OPAL Discussion Forum

[Dragos Constantin <Dragos.Constantin AT varian.com>]

Hi David and Andreas,

Thank you for your messages. I was busy the last few days looking into the subject.

 

My problem involves standing wave linacs.

 

David, do you have any insight into how easy it is to adapt ‘Hellweg’ to deal with standing wave linacs? Strategically I am thinking at a multi-step approach where we validate and benchmark Hellweg first, and then we implement beam loading into OPAL.

 

Thanks,

Dragos

 

From: David Bruhwiler <bruhwiler AT radiasoft.net>
Sent: Tuesday, August 4, 2020 8:13 AM
To: Adelmann Andreas (PSI) <andreas.adelmann AT psi.ch>
Cc: Dragos Constantin <Dragos.Constantin AT varian.com>; opal AT lists.psi.ch
Subject: Re: [Opal] beam current and final accelerating energy value

 

Hi all,

 

Andreas -- thanks for referencing the work by Dan, Stephen and Nathan. I agree that their work could be used together with OPAL to address the problem of beam loading.

 

The Hellweg code (primary author Sergey Kutsaev of RadiaBeam) is well-benchmarked and fast software for the simulation of low-to-moderate energy electron beams in traveling wave linacs. You can find the source code, with documentation and a list of references on GitHub, https://github.com/radiasoft/rslinac

 

One could use Hellweg to find the cavity amplitudes and phases in the presence of beam loading, and then use these settings in OPAL to get an independent assessment of the resulting beam dynamics.

 

Best,

David

--

David Bruhwiler

CEO | RadiaSoft

720-502-3928   x700

radiasoft.net | sirepo.com

 

 

 

On Tue, Aug 4, 2020 at 6:30 AM Adelmann Andreas (PSI) <andreas.adelmann AT psi.ch> wrote:

Hello Dragos, beam loading can not be modelled with the current version of OPAL. 

 

However in https://journals.aps.org/prab/abstract/10.1103/PhysRevAccelBeams.20.052002

an interesting method was published which could be implemented without bigger problems in OPAL.

This could be an interesting project if you want to be involved with the OPAL development. 

 

 

 

Cheers A

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On 3 Aug 2020, at 10:55, Dragos Constantin <dragos.constantin AT varian.com> wrote:

 

Dear All,
I am modeling an emitted beam being accelerated by a few RF cavities. The beam
emission time is longer than the RF period. I expect to see that final beam
energy has some dependence on the beam current but it does not. How can I
correctly model the beam loading in OPAL?

Thanks,
Dragos

 

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