How to active bremsstrahlung by electron?

How to active bremsstrahlung by electron? when uisng 110keV electron to bomb tungsten, it seems no bremsstrahlung photon.the .

inp file is uploaded
BombTungsten.inp (1.4 KB)

here is the result.

here is the result from phits. it seems right.

Hi Lihua,

I quickly ran your input file out of curiosity. You are already generating the bremsstrahlung spectrum that you attached. However, your Tungsten is heavily attenuating forward-propagating photons, such that your current USRBDX is empty. If you create a new USRBDX from your target to your void regions (upstream direction), you will see the below spectrum:

I find it helpful to use a USRBIN to visually see what is happening in your simulation too. Below is a very very basic R-Phi-Z USRBIN plot from your input file, which scores photon fluence:


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Dear Lihua Li,

In addition to Ted’s much appreciated and very pertinent comment, I’d like to point out that the initial EMFCUT cards you passed were ineffective, since you’re not specifying the materials/regions to apply
them to (!).

You then get the default transport/production cuts for electrons and positrons prescribed by your chosen DEFAULTS card, specifying EM-CASCA in your case, implying 100 keV thresholds for electrons and 10 keV for photons (you can triple check in the output file). You’re killing your e- a mere 10 keV below primary energy.

With kind regards,


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@ Ted Liang,@ cesc, thanks!