CEA Codes forum

I would like to ask about the gas scattering implementation in Tracewin.
In the "GAS" command, only pressure and atomic number are demanded, but no cross section is required for scattering calculations (the cross section in the GAS command will be used for gas stripping, I assume). I would like to know if this feature has been validated (benchmarking with some other codes) and if we can rely on such results. I would appreciate more information about the physic model describing such interactions.

Dear Conoa (if it is not your name, please excuse me),

This option calculates the elastic Coulomb scattering on the residual gas (nucleus). It uses Rutherford cross section.
In 1995, the probability formula had been validated on an experimental set-up [Jacow- accelconf.web.cern.ch/e96/PAPERS/MOPL/MOP017L.PDF].
This probability law has then been implemented in Tracewin a few years after, applying a random process to each particle at each step.
I remember that we made a benchmark at that time using dense gas in which the number of scattered particle was high (and can be seen, as, at that time, simulation time was much longer than now ).
As, since then, many new implementations have been added in TraceWIN, I recommend you to redo the benchmark (in a drift, with high pressure, in well known conditions where analytic shape can be predicted) by yourself.
Please let us know (in this forum), if your benchmark shows good results or shows that debugging is necessary.

Best regards.

Nicolas.

Thank you Nicolas.
I will keep you informed
Conchi Oliver