`enable_em` not working

[Jean1995]

When I try to enable the simulation of electromagnetic cascades, i.e., setting config.enable_em = True, I receive the error

FileNotFoundError: [Errno 2] Unable to synchronously open file (unable to open file: name = '/home/jean/.local/lib/python3.8/site-packages/MCEq/data/mceq_db_EM_Tsai-Max_Z7.31.h5', errno = 2, error message = 'No such file or directory', flags = 0, o_flags = 0)

The file mceq_db_EM_Tsai-Max_Z7.31.h5 doesn't seem to exist, I also can't find the code which is supposed to download this file... Where is my mistake, how can I get this file? 🙂

[afedynitch]

Hi!

Well, that file is not public unfortunately for reasons you may know.

I'm wondering if can calculate inclusive cross sections for e+- pair production or bremsstrahlung with PROPOSAL? If yes, I could enable EM without using this special file..

[MarkWalker]

Hello.
Thanks for making MCEq available to everyone - it's very useful.

I would also like to enable EM interactions, but I'm experiencing the same issue reported by Jean1995 so presumably there isn't a workaround yet?

I don't know why the EmCA file is not public, but I guess it wouldn't help me if I did?

[afedynitch]

Hi Mark,

It won't be public. Perhaps we will develop a new approach, but at the moment, there is no priority for it. If you can provide any convincing use case, that part may have the priority bumped.

[MarkWalker]

OK, thanks for letting me know, Anatoli. My application is very much a niche, so I certainly wouldn't ask you to change your priorities on account of what I'm doing. (I have an astrophysical application, rather than a terrestrial one.) Slightly surprising to me that most of your users don't need the EM shower as (according to MCEq!) most of the energy ends up there, and I would've imagined that'd be important for many applications.