Changes between Version 24 and Version 25 of StoutData


Ignore:
Timestamp:
2017-09-03T15:24:10Z (3 weeks ago)
Author:
Gary J. Ferland
Comment:

explain the TP problem with ADF04 file format - a significant minority have a TP of 1e-30 s-1 since they do not allow a TP of 0 for forbidden transitions

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  • StoutData

    v24 v25  
    139139These require Python3.
    140140
    141 == ADF04. energy levels, transition probabilities, and collision strengths ==
     141== ADF04, energy levels, transition probabilities, and collision strengths ==
    142142The script to convert from the ADF04 format used in the
    143143[http://open.adas.ac.uk Open-ADAS] database can be found
    144144in scripts/ in the root directory, named '''adf042stout.py'''.
    145145A possibly out of date version may be found [https://github.com/mattlykins/Adf04ToStout here].
     146
     147The ADF04 standard requires that ''all'' upper and lower states be joined with a non-zero transition probability.  In practice, something like 20% of the TP will have a value of 1e-30 s^-1^, the smallest value they use.
     148Many of these transitions are completely forbidden and, if the line exists, Cloudy has to transfer the line, no matter how small the TP.  We introduced the rule that we do not create emission lines
     149when the TP is 1e-30 s^-1^ or smaller.
    146150
    147151== NIST, energy levels and transition probabilities ==