Question of ions supported by CHIANTI continuum calculation

[Conor Perks]

Hello,

My name is Conor Perks and I'm a graduate student at the MIT Plasma Science and Fusion Center working on x-ray spectroscopy in tokamaks. I'm interested in using CHIANTI to calculate the free-free and free-bound continuum emission for synthetic spectra I'm simulating. It would immensely save me the time of copying all the Gaunt factor tables in Karzas and Latter 1961 myself.

I've been aware of CHIANTI for some time, but have avoided it as the astrophysics community is concerned with lower-Z elements than in the tokamak community. So I figured out alternative methods to calculate line radiation and ionization balance. Would there be a similar issue with using the continuum calculations?

The exact species I'm considering are W, Mo, Xe, Kr, Ar, Cu, Ni, Cr, and lower. If it's a question of transition energies, ionization potentials, and energy levels then I already have the data so could implement a workaround. If so, where would I need to look to import the necessary data? Are there already convenient functions in ChiantiPy, i.e. to load the relevant Gaunt factors?

Thank you in advance for your time,

Conor

[Ken Dere]

Hi Conor,

first about ions in the CHIANTI.   We do include ions of Ar, Cu, Ni, and Cr, but not every single ionization stage.  if you go to our webpage CHIANTI and go to direct access and the to data files you will see a chart with all possible ions from H through Zn and if the ion is in CHIANTI, then it will have a link to the data files.

Also, if you have already downloaded the database, go to $XUVTOP/masterlist and the file masterlist.ions has a list of all ions in the data base.

the gaunt factors are read while building the ChiantyPy.tools.data class.

CHIANTI was developed for studying astrophysical spectra and  so there are some complications in using it for laboratory spectra.  One this is the use of abundance files with generally solar photospheric abundances.  You could use the unity.abund file were all abundances are set to 1.0

Then there is the ionization equilibrium files that are used.  I am not sure what alternative there is to that except to make one that just contains 1.0 for everything.

hope this helps

Ken