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AW: [Opal] Transit time factor calculation in OPAL

From: Snuverink Jochem <jochem.snuverink AT psi.ch>
To: Malek Haj Tahar <malek AT transmutex.com>
Cc: "opal AT lists.psi.ch" <opal AT lists.psi.ch>
Subject: AW: [Opal] Transit time factor calculation in OPAL
Date: Wed, 8 Mar 2023 16:08:55 +0000
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Dear Malek

Apologies for the late answer.

The correction is done when a particle step crosses an RF cavity. In this case the step is split in two, one with the old particle energy up to the cavity, and one with a step after the cavity with the new particle energy. I believe this is what is meant with the transit time correction.

To see the code, this is implemented twice (in the same way) at:

https://gitlab.psi.ch/OPAL/src/-/blob/master/src/Algorithms/ParallelCyclotronTracker.cpp#L1971

and

https://gitlab.psi.ch/OPAL/src/-/blob/master/src/Algorithms/ParallelCyclotronTracker.cpp#L3242

Best wishes,

Jochem

Von: opal-request AT lists.psi.ch <opal-request AT lists.psi.ch> im Auftrag von Malek Haj Tahar <malek AT transmutex.com>
Gesendet: Dienstag, 21. Februar 2023 11:35
An: Opal AT lists.psi.ch <Opal AT lists.psi.ch>
Betreff: [Opal] Transit time factor calculation in OPAL

Dear OPAL developers,

Looking at the RFcavity model implementation in OPAL, one could read in the manual that

"The RF cavities are treated as straight lines with infinitely narrow gaps and the electric field is a �δ function plus a transit time correction."

Could you please let me know where to find more info regarding how OPAL computes the transit time correction? Is this an analytical model available somewhere?

Many thanks for your time and support!

Best regards,

Malek

------------------------

Dr. Malek Haj Tahar

Computational physicist

Transmutex SA

Mobile: +41 784 202 022

Chemin de Blandonnet 8

1214 Genève (Vernier)

www.Transmutex.com

AW: [Opal] Transit time factor calculation in OPAL, Snuverink Jochem, 03/08/2023
- RE: [Opal] Transit time factor calculation in OPAL, Daniel Winklehner, 03/08/2023
  - Re: [Opal] Transit time factor calculation in OPAL, Malek Haj Tahar, 03/09/2023