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**
**  RF HEATING AND CURRENT DRIVE INPUT FROM INPUT DIFF COEFFS
**  namelist rfsetup
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**
**  
**  rdcmod="format1" or "aorsa", then read in externally calculated
**    velocity space diffusion coefficient D_u0u0 in cgs units.  This
**    is a bounce-averaged coeff giving diffusion in 
**    momentum-per-mass coordinates: u0=x*vnorm, where x is
**    the code normalized momentum-per-mass coordinate and pitch
**    angle theta0.  The u0,theta0 are at minimum-|B| on a flux 
**    surface.
**
**    "format1" is data formatted according to AORSA convention:
**    Data is given on a regular grid of u_par0 and u_perp0, 
**    with upar0: -unorm,+unorm, uperp0: 0,unorm.
**    (Velocity unorm, here, is specified in the file, and may
**    be different from cql3d vnorm (specified through enorm).
**    (for relativistic cases, unorm refers to momentum-per-rest-mass.)
**    If unorm in the file is less than cql3d vnorm, then the
**    diffusion coeffs above unorm will be set =0. on the cql3d grid.) 
**    Data is read in from file du0u0_input, with format shown
**    in subroutine rd_diff_coeff.
**
**    The read in data is interpolated onto the code
**    momentum-per-mass grid.
**    ===>  Presently, the rdcmod radial grid IS TAKEN TO   <====
**    ===>  BE THE SAME as specified rya(1:lrz) for cql3d.  <====
**    Except, if data is given on twice as many flux surfaces as
**    specified by lrz, then the data set is reduced by omitting
**    data for every second flux surface.
**
**   Multi-file "aorsa"/"format1" set up. Can input multiple diffusion
**     coeff files and ql diffuse separate or
**     the same general species depending on setting of
**     nrdcspecies(1:nrdc).  [BH110608]
**    
**   nrdc=number of "aorsa"/"format1" files to be read (must be .le.
**     parameter nrdca, presently set = 10). Default nrdc=1 (gives backwards 
**     compatibility); that is, the default input file is named du0u0_input.
**     It is assumed that the velocity and radial grids 
**     are the same in each of the input diff coeff files.
**   
**   rdcfile(1:nrdc)=file path for each file (up to 256 characters).
**             default: rdcfile(1)=du0u0_input, rdcfile(2:nrdca)="notset"
**   
**   nrdcspecies(1:nrdc)=general species index to which the respective
**     diffusion coefficient files are applied.
**     Default: nrdcspecies(1:nrdca)=1
**   
**   rdcscale(1:nrdc)=scaling of each of the diffusion coefficient files.
**     Default: rdcscale(1:nrdca)=1.
**           If nrdc=1 and namelist rdcscale(1).ne.1., then use this value.
**           However, if nrdc=1 and rdcscale(1).eq.1.(e.g., the default)
**           then set rdcscale(1)=pwrscale(1).
**           (This maintains backwards compatibility.)
**
**   rdcmod="format2" reads in velocity space diffusion coefficient 
**    from files du0u0_grid and du0u0_rnnn, where nnn=[001-n_psi], 
**    and n_psi is number of radii given in du0u0_grid.  Thus,
**    the set of velocity-space diffusion coeffs are given in a
**    separate file for each radius, as provided by the DC diffusion
**    coefficient code.   Formats are otherwise
**    similar to "format1".  Note restriction re rya()!
**    Presently not set up for multiple radial sets of diffusion coefficient
**    files (as in rdcmod="format1" case, but this feature can readily be 
**    added if there is a need,  BH180507).
**
**    default:  rdcmod="disabled"
**
**  plturfb (in namelist section setup, see plot controls above) gives
**    plots of urfb diff coeff.
**
**  rdc_netcdf=ne."disabled", then
**    rdcb,etc.,  written into a netcdf file mnemonic//'_nn_rdc.nc', 
**    where nn=number of diffusion coefficient input file.
**          ="one", or "enabled", write first set of diff coeff
**            to mnemonic//'_rdc.1.nc'
**          ="all", write mnemonic//'_rdc.n.nc', n=1:nrdc
**          (default="all")
**    The rdcb, rdcc, rdce, rdcf are on the cql3d vel space grid.
**    Amount of output affected according to netcdfshort='long_urf'.
**
**  pwrscale(1) [from urf section of code, presently used to
**               scale input value of diffusion coeffs, but
**               can be superceded by rdcscale(1),
**               (above) for rdcmod="format1"]
**
**  rdc_upar_sign=+1. to maintain u_par sign convention of du0u0_input,
**                -1., to reverse order.   This should be used for DC
**                when the toroidal mag field is negative(clockwise),
**                since upar in DC is pos in dirn of B-field,
**                but in cql3d, upar is positive when in toroidal dirn.
**                (default=+1.)
**
**  rdc_clipping='enabled' for clipping of diffusion coefficient spikes
**               which sometimes occur near the trapped-transiting bndry.
**               Clipping is according to "Running Median Filters and 
**               a General Despiker", John R. Evans, Bull. Seismological
**               Soc. Amer. (1982).  Efficacy of the method has been
**		 investigated with python plotting script
**               plot_DC_multiR_format_cqlf.py.
**               default='disabled', for backwards compatibility.
**
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