The Stopping Power Conundrum

It is well known that the stopping powers in RUMP are not very good for high Z projectiles.  Why do I let this problem persist?  The issues are not all that complex and basically come down to three issues:

  1. For the majority of users, ion beam analysis is done using alpha particle scattering and the existing stopping power calculations are pretty good.  There are now modifications to improve on the He stopping power in Si and C.
  2. My own work has only involved He and H backscattering to date and I haven't had to personally worry about the problems with high Z projectiles
  3. I've been informed that I cannot include more recent stopping power calculation algorithms in a commercial (for fee) package.  The copyright issues are unclear ...
The second of these issues is minor and I would be more than happy to implement a much more comprehensive algorithm for stopping powers.  The third, though, is much more difficult to work around.  Even if I write the code and attempt to place it in the public domain, there remains a very strong conflict of interest since I also sell RUMP.  I do not doubt that the copyright lawyers would have no difficulty charging a violation, and I do not have the will or resources to challenge such a lawsuit.

The best that I believe I can do legally is to provide an internal mechanism for loading alternate stopping power calculation routines.  Users can write (or download from others) a DLL which provides more accurate stopping power information.   The NT version presently has this DLL load mechanism built in.  UNIX does not support DLL's but I'd be happy to help users modify the code if an appropriate public domain algorithm were available.

What is needed?

What I can (and will) do:

IF you can show that the code has all appropriate licenses and copyright permissions, I would like to negotiate an agreement to include the code in the default RUMP distribution (with appropriate royalties).

Contact Mike Thompson if you want to discuss these issues further.