mp Diffusion
Directories mupd[1-3], because mupd kinetics is used, but transfer set to 0.
Alas, we have not real thermal model in Mucat, so mp scattered below 0.04 eV are
reset to 0.04 eV. mp+H2 cross sections given for 30K (rotational excitation).
Results therefore are qualitative only.
For mp cross section used, click here.
1E7 statitistics.
root
edit to slice1, mupd1 etc
.L mupd1.C
slice()
draw()
c1->Print("mupd1.gif")
In the following we display the range distribution at decay for different
time slices multiplied by 1/R^2.
thermal E=0.04eV, mup(F=0) only, mupd1
thermal E=0.04eV, mup(F=0) & mup(F=1), mupd2
epithermal E=4 eV, mup(F=0) & mup(F=1), mupd3
The values for the time slices are given in the pdf file. The
X-axis is in mm at 0.01 gas density.
The pdf files also displays the mean and the rms radius for the original Monte Carlo distributions
mupd[1-3] and for the 1/R^2 multiplied distribution. Is appears that the ideal diffusion
equation is only a rough approximation to the real process. The differences for differing
kinetics assumptions are small. For MC simulation one could either take the slices, the mean and
rms or the diffusion approximation, in decreasing order of precision. Quantitatively, the presently
calculated diffusion radii seem larger than in our original proposal.
We could ask A. Admaczak for better estimates, if required.