GE FULL PROBLEM (20 microsecs)
After running the code for 20 microsecs, we again see the
anomalous peak at the center (r = 0).
The better results after "1 microsec" were the result of the new cross-sections.
Apparently, the larger excitation
cross-section
used by XPDP1 creates an energy sink which slows down the ionization rate.
However, even after 1 microsec, there is a large peak in the rate of
ionization at the center as seen in
Full Problem after 1 microsec.
Eventually, this peak in ionization rate at the center leads to
the familiar large axial density peak. The new
larger excitation cross-section just creates an energy sink that slows down
the ionization rate and the axial peak creation by about a factor of 5.
So, you begin to see the peak at 5 microsecs rather than at
1 microsec (as with the previous cross-sections).
