To create a matlab structure with cooling factors and average charge for a list of impurities:
  - Specify the list of imputities in 'chargemass.m' (already a default one)
  - Use only 'make_Lz_table_with_H0.m' which uses also neutral deuterium for computations including charge exchange
  
In 'make_Lz_table_with_H0.m', one can specify a preferential year for a given element (e.g. for W year 50 is used)
Some preferential years can also be added in 'init_adas.m'

It will download and read ADAS tables with 'read_adf11.m' (if url changes in the future, should be modified in this file)
Then the fractional abundances are computed with 'equi_ionisation.m' and the cooling factors with 'compute_lz.m'.

Finally 'Lz_zave_HDT0.mat' will be created together with a corresponding matlab function (using 'writestruct.m').
The latter is used in 'code/eval/private/qnze.m' and 'prad_adas.m'.
Since for the same years the ADAS data can be modified, a default matlab function is given with the time of
creation. This default function is used in 'qnze.m' and 'prad_adas.m' but can be changed with user
specific 'Lz_zave_HDT0.m' functions.
