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Re: [Opal] Particle interactions for news developments in OPAL

Chronological Thread 
  • From: "Adelmann Andreas (PSI)" <andreas.adelmann AT>
  • To: "Baumgarten Christian (PSI)" <christian.baumgarten AT>
  • Cc: "opal AT" <opal AT>
  • Subject: Re: [Opal] Particle interactions for news developments in OPAL
  • Date: Tue, 10 Apr 2018 06:19:02 +0000
  • Accept-language: en-US, de-CH
  • Authentication-results: localhost; dmarc=skipped

Dear Andreas et al,

very good idea indeed.

One comment: I would expect that the van-der-Waals 
constants "a" and "b" can be neglected at gas densities 
in which cyclotrons are able to work, probably even close 
to internal ion sources.

You are probable right and this brings an other question to the surface: how
do we specify the pressure in the vacuum chamber. Do we add to each 
lattice element pressure value? Do we assume over a lattice element the pressure
does not change? 

Of course it would be interesting to have this kind of loss
Monte Carlo also for H2+, though I am not sure if cross
section data for different vibration states are known…

There is some knowledge, the figure below is from

One question: Did you also consider to trace stripped 
ions to the walls of the vacuum tank to enable for a 
prediction of activation hot spots?

See my comment to Jon and yes OPAL can handle geometries and we 
should be able to know where particles are hitting the wall. 


-- Christian

Dr. sc. math. Andreas (Andy) Adelmann
Staff Scientist - Deputy Labor Head LSM
Paul Scherrer Institut OHSA/D17 CH-5232 Villigen PSI
Phone Office: xx41 56 310 42 33 Fax: xx41 56 310 31 91
Phone Home: xx41 62 891 91 44
Friday: ETH CAB F37 or HPK G 28   +41 44 632 75 22
The more exotic, the more abstract the knowledge,
the more profound will be its consequences.
Leon Lederman

Begin forwarded message:

From: "Calvo Portela, Pedro"
<Pedro.Calvo AT<mailto:Pedro.Calvo AT>> Subject: Particle
interactions for news developments in OPAL
Date: 6 April 2018 at 14:11:50 GMT+2
To: "andreas.adelmann AT<mailto:andreas.adelmann AT>"
<andreas.adelmann AT<mailto:andreas.adelmann AT>> Cc: "Oliver
Amoros, Concepcion"
<concepcion.oliver AT<mailto:concepcion.oliver AT>>,
"daniel.winklehner AT<mailto:daniel.winklehner AT>"
<daniel.winklehner AT<mailto:daniel.winklehner AT>>,
"jralonso AT<mailto:jralonso AT>"
<jralonso AT<mailto:jralonso AT>>,
"conrad AT<mailto:conrad AT>"
<conrad AT<mailto:conrad AT>>


As a OPAL project collaborators, we are interested in vacuum stripping
implementation in the code. So, we have drafted  a document that
summarizes the main models for particle interactions in a cyclotron, as
Andreas Adelmann suggested us few months ago. This is a first draft,
focused on H- ions, but with references to H2+ ions. In addition to the
stripping of residual gas I have included the magnetic field stripping
Here a link ( with
the LaTex document. We would appreciate any comments or suggestions on
this topic

Best regards

Pedro Calvo Portela
Unidad de Aceleradores - CIEMAT
Avenida Complutense 40, Edificio 7
28040 Madrid
Tel: +34 – 91 496 2554


Paul Scherrer Institut
Dr. Christian Baumgarten
Accelerator Physicist 

Large research facilities
5232 Villigen PSI

Phone +41 56 310 3780
christian.baumgarten AT

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