Sources input parameters (parameter -- description -- options, with default given first):

source_option -- determines how source profiles are specified -- 'analytic' or 'iterdb'
source_file -- file with source profile data (if using 'iterdb' option) -- path of profile input file
source_time -- time during discharge to sample experimental data in seconds (if using 'iterdb option)
include_alphas -- include alpha heating source -- default .true.
include_radiation -- include Bremstrahlung radiation -- default .true.
write_pwr_profiles -- write to file radial source profiles -- default .false.
powerin -- external power input in MW (if using 'analytic' source_option) -- default 50.0
densin -- external density input (if using 'analytic' source_option) -- default 0.0
radin -- spatial mean of Gaussian power deposition profile (if using 'analytic' source) -- default 0.0
src_ratio -- fraction of external power going to ions (if using 'analytic' source) -- default 0.5
psig -- width of power input profile in units of minor radius (if using 'analytic' source -- default 0.1
nsig -- width of density input profile in units of minor radius (if using 'analytic' source -- default 0.1