chem: fix error handling of preprocessor

[VincentVanlaer]

The code to preprocess data about the chemical species does not properly handle errors when reading from the mass table. Currently only one element (re203) has an entry in this table that does not contain data. Instead, the mass excess of the previous row is reused. The processed data file included in the repository does not have this issue, so either it was manually corrected or the tool didn't have the bug when it was generated.

This might not be the best solution (maybe the error should be reported in some way, or the data tables updated), but now it is no longer using bogus data.

[Debraheem]

@VincentVanlaer Let's try to fix or fill in the missing data!

When I rebuild the chem data and I look into "$MESA_DIR/chem/preprocessor/chem_input_data/winvne_v2.data" I see:

re202 202.000 75 127 6.0 -4.190 frdm 1.00000E+0 1.00000E+0 1.01000E+0 1.04000E+0 1.08000E+0 1.13000E+0 1.20000E+0 1.27000E+0 1.35000E+0 1.44000E+0 1.53000E+0 2.12000E+0 2.93000E+0 4.09000E+0 5.75000E+0 8.22000E+0 1.20000E+1 1.79900E+1 2.77800E+1 7.33800E+1 2.25110E+2 8.06240E+2 3.34039E+3 1.53942E+4 re203 203.000 75 128 5.5 0.000 frdm 1.00010E+0 1.00094E+0 1.00324E+0 1.01286E+0 1.02826E+0 1.04818E+0 1.07172E+0 1.09836E+0 1.12779E+0 1.15986E+0 1.19453E+0 1.40957E+0 1.71410E+0 2.16059E+0 2.84964E+0 3.97023E+0 5.88109E+0 9.27634E+0 1.55297E+1 5.07458E+1 1.95413E+2 8.58997E+2 4.20683E+3 2.19302E+4 re204 204.000 75 129 4.0 6.050 frdm 1.00000E+0 1.01000E+0 1.04000E+0 1.15000E+0 1.33000E+0 1.57000E+0 1.85000E+0 2.17000E+0 2.53000E+0 2.92000E+0 3.34000E+0 6.05000E+0 9.99000E+0 1.57900E+1 2.46100E+1 3.84800E+1 6.10700E+1 9.92600E+1 1.66250E+2 5.17410E+2 1.86336E+3 7.71653E+3 3.59944E+4 1.00000E+5

It doesn't appear as though the data from the previous row is being reused? Am i missing something?

[Debraheem]

See https://github.com/MESAHub/mesa/compare/main...chem/fix_preprocessor_error

[VincentVanlaer]

It is not the data from the winvne_v2 table that is getting reused, but the data from the masslib_library_5.data file. See the following extract from this table (starting at line 4533).

  73 203            frdm        19880         #
  74 203            frdm         8940         #
  75 203            frdm            #         #
  76 203            frdm        -8640         #
  77 203            frdm       -15430         #

The Re203 isotope is the 75 203 line. The data that is being reused here is the line above (notice that the 8940 also appears in your diff in the last column)

[Debraheem]

@fxt44 > https://reaclib.jinaweb.org/links.php, "NucDataLib (currently unavailable)", do you know a location where we could get the mass excess for this isotope? The link in the masslib file is also broken. One could linearly interpolate between values get say ~ 150 for the mass excess in the mean time? The question is why it was ever "#".

[fxt44]

only re185 is stable; re203 is way out in the neutron-rich region. i looked around and didn't find much, even at the national data centers. there is this one https://materials.springer.com/lb/docs/sm_lbs_978-3-540-70609-0_2265 but i can't access it (springer paywall). i suspect any reasonable value will be ok, the # probably means "no value".

[fxt44]

frdm 2016 is at https://www.sciencedirect.com/science/article/abs/pii/S0092640X1600005X and it does list values for re203, although not explicitly the mass excess, but the binding energy, from which one can get the mass excess.

[Debraheem]

only re185 is stable; re203 is way out in the neutron-rich region. i looked around and didn't find much, even at the national data centers. there is this one https://materials.springer.com/lb/docs/sm_lbs_978-3-540-70609-0_2265 but i can't access it (springer paywall). i suspect any reasonable value will be ok, the # probably means "no value".

okay, I'll try both of these approaches. I might be able to access this paper free of charge on site at lanl tomorrow.

[Debraheem]

<Mexcess|Re203,75|Mexcess> = 0 :)