Date: Mon, 6 Jan 2014 15:44:28 +0800 (CST)
Hello,
Everyone!The attachment is my input file and the figure of flux density.
(1)In my input file,the primary electron energy is 20KeV;the carbon target is just 1um. I find there is a big difference between single scattering and mutiple scattering for the figure of flux density on the target side.I just don't know why this happened.I doubt when the primary electron energy is 20KeV and the target is 1um,multiple scattering is not applicable.Anyway,Could you explain this to me?
(2)I change the primary energy.Now the primary electron energy is 100KeV and the target stay the same.You can see from the attached figure,the results are almost the same from single scattering and multiple scattering for the figure of flux density on the target side.Similarly,I don't know why this happened.
(3)In the Fluka Manual,it says
"Although in high-Z materials the Moliere
multiple scattering model becomes unreliable below 20-30 keV, a single-scattering option is available which
allows to obtain satisfactory results in any material also in this low energy range.
The minimum recommended energy for primary electrons is about 50 to 100 keV for low-Z materials
and 100-200 keV for heavy materials, unless the single scattering algorithm is used. Single scattering transport
allows to overcome most of the limitations at low energy for the heaviest materials at the price of some
increase in CPU time."
Is there a link between this part and my question?
(4)Last but not least,I think single scattering is universally applicable for any thickness of material and any energy(low energy like below 20-30KeV and high energy).But,multiple scattering is based on Moliere theory and has its limits of validity.Am I right?
On the other hand,the Manual says "when the energy is low or the region is thin,we should use single scattering".But how low is the energy? How thin is the region?
Best Regards
Chen Yuan
- application/octet-stream attachment: rl.inp
(image/jpeg attachment: the_figure_of_flux_density_20KeV_.jpg)
- application/octet-stream attachment: the_figure_of_flux_density__100KeV_.fig