[FLASH-USERS] Ionization Initial Condition Question

[Roberto Alejandro Colon Quinones]

I am a new user of FLASH and have run into a question I was hoping the community could help with. I am trying to simulate the laser induced breakdown of a nitrogen gas by modifying the laser slab example but have run into some difficult defining initial conditions for the ionization level. Namely it seems that YE (defined as the ratio of avergage ionization to average atomic mass in cell) is initialized to ~ 0.006 in the simulation. Given that I want to watch the plasma to decay to a number density of 10^13 cm^-3, it seems that I need to initialize YE to a much lower value. My specific questions are highlighted below:

1. How do you initilize YE for the +MTMMMT EOS module. Right now in initial conditions, I do not see any way to directly set the ionization level in the medium for the laser slab example. In the laser slab it is initialized to be ~0.006 which results in an initial electron density that is too high.

2. Is there any lower limit to the initial ionization level for stability purposes? Given that I want to watch the plasma decay from 10^18 cm^-3 to 10^13 cm^-3 via diffusion, my initial gloval ionization level needs to be low.

3. Can you specify an initial grid dependent ionization level in the +MTMMMT module, namely only in a given target region?

Thanks,

Roberto
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20170816/98e863f2/attachment.htm>