[FLASH-USERS] Flash LaserSlab ionmix

[Klaus Weide]

On Wed, 21 Jun 2017, stylianos.passalidis17 at imperial.ac.uk wrote:

> Good morning, I am working on Flash for HEDP purposes and I would like 
> to ask how to find a .cn4 file for hydrogen since the only available are 
> for polystyrene, Al and He. Is there such file in order to simulate 
> hydrogen- laser interaction?

Stylianos,

Welcome to FLASH-USERS.

There are actually some more IONMIX files in the FLASH release than the 
ones with the suffix ".cn4" that you found. You can also find several 
files with ".imx" which have been generated with IONMIX and may be usable 
for you. Also possibly some files ending in ".cnr".

Unfortunately not all ".imx" files appear to be in the same format.
Here is a quick guideline -

1. If the first four lines look like this:

   ======================================================================  
            21        17                                                            
     atomic #s of gases:          2                                                 
     relative fractions:   1.00E+00                                                 
              30
   ======================================================================  

   then assume it is an IONMIX 4 output file.

2. If the first four lines look like this:

   ======================================================================  
            30         5                                                            
     atomic #s of gases:          1                                                 
     relative fractions:   1.00E+00                                                 
    0.100000E+010.140000E+020.333333E+00-.100000E+01         100
   ======================================================================  

   then assume it is an IONMIX 1 output file.

3. If the first four lines look totally different from these two samples,
  assume neither! 


The important tell to distinguish between IONMIX 4 and IONMIX 1 is
whether the fourth line contains 5 numbers (4 reals and 1 integer) or
just 1 integer.  (In either case the integer represents the number of
radiation energy groups for which the file contains opacities.)

The IONMIX4 format is documented in section

   22.4.6 The IONMIX EOS/Opacity Format

of the Users Guide (e.g., https://flash.uchicago.edu/site/flashcode/user_support/flash4_ug_4p4/node140.html)
where IONMIX1 (just called IOMNIX there) is also mentioned.


In your case, you may be able to use an IONMIX1 file "h-100grp-lte.imx"
which is included in the FLASH release. You should find copies in the
Eos and Opacity units. Let us know if this does not solve your problem.


Klaus