X-ray from srf cavity field emission

Hi everyone, we are interested in simulating X-ray pattern generated by field emission in a srf cavity.
We have become aware that SLAC has developed a FLUKA code to reconstruct such process for srf cryomodules.

We’d like to know whether this routine is somehow public or a private property of SLAC. In the former case, we would like to use it to simulate the behavior of our experimental facility during cavities power test, then allowing us to better understand some puzzling radiation pattern induced by the cavity.

We already developed some very simple cavity models exploiting the built-in functions of FLUKA (CERN release) but - in order to develop a more realistic model - we’d need first, to import the CAD cavity model, and then to simulate both the RF field and the electron emission model (Fowler-Nordheim-wise).

About the CAD import issue, we have already tested SALOME open source software and FLuDAG , but without success. (Troubles in installation).

Thank you,
Elisa

Hello Elisa,

have a look at the paper by Zhou et al., https://academic.oup.com/rpd/article/185/1/124/5253234 .
They use CST Studio to solve for the RF fields. Field emission is modelwed by the Fowler-Nordheim equation. The dynamics of the emitted electrons in the RF fields is calculated by the CST PIC solver, leading to a distribution of impact energies, which are input to a stopping-, bremsstrahlung and photonuclear claculation in FLUKA.

Best regards, Thomas ( @totto )

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Adding to the reply of @totto, see this publication from SLAC. If you can run/get help in running a particle tracking code with a realistic model of the cavity to get particle information, then implementing its output in the FLUKA with the source routine should be doable. While F-N model predicts the trend well, the magnitude is dependent on less understood modifying factors. See “Padamsee et al. RF Superconductivity for Accelerators, 2nd Edition”
Good luck and let us know about your progress.
Sunil

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