Problem 946

Created attachment 2 [details]
sample output showing problem

I'm running a simple simulation to generate electron cascades (including Auger electrons) in sodium iodide subsequent to low energy photoelectric and Compton interactions for gammas.  The 28.3 keV fluorescent xray is never generated, although higher-energy xrays at 28.6 keV and 32-33 keV and lower energy xrays at 0.5-5 keV are generated.

Quite often, only a photoelectron with energy E-32.2 keV is generated for an incident gamma of energy E, and the dE for the gamma is 32.2 keV.

This behavior occurs with both low energy and Penelope processes.  A sample output is attached.

This may be related to problem 933 and also to a dialog from the user forum pasted below.

Thanks!

Dialog title "Losing characteristic radiation, where is problem?":

On Mon, 29 Aug 2005, Hayk Gabrielyan wrote:

> *** Discussion title: Event and Track Management
> Email replies to PublicHyperNews@slac.stanford.edu must include:
>   In-Reply-To: <"/eventtrackmanage/374/1/1"@geant4-hn.slac.stanford.edu>
>   Subject: ...change this to be about your reply.
> 
> Dear Vladimir IVANTCHENKO!
> 
> thank you for fast reply.
> 
> But I have a question again. I am "gathering" energy deposit of gammas
> via electron kinetic energies. I've an initial gamma, after interacting
> (photo, compton effects), I get electrons. I am summarizing initial
> kinetic energies of electrons and kill them. I thought, that I must get
> more precised data. But as I've mentioned above in my topic, nearly 10%
> of the electrons which I must get from the electron conversion from high
> shells (N,M) to K shell (interval ~28-29keV)gammas, but I haven't. In
> other 90% of acts, that gammas (28-29keV) appear, with the following
> photoeffect and electron emission.
> 
> I want to understand, why I am getting this result? Is there a logical
> mistake?
> 
> thank you again
> 
Hello,

If you are using standard package, then no atomic deexcitation is
simulated. If you are using lowenergy, then fluorescence is active by
default with the default energy threshold 250 eV. To have a complete
deexcitation simulated one has to activate also Auger production and
establish needed thresholds for dexcitation gamma and Auger electrons.

If you are sure that deexcitation is active and threshold are on the level
you want and there is no existing lines in the final spectrum, then it may
be a subject of a bug report.

VI