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HOW TO CREATE THE CHIANTI LINE EMISSIVITY DATABASE       01Aug2010

NOTES:
a. This version of PINTofALE is designed for use with CHIANTI v6
b. For convenience, we have also provided a tar file containing the
   CHIANTI line emissivities computed at various densities, in
        http://hea-www.harvard.edu/PINTofALE/PoA_chianti_2.0.tar.gz
   The following instructions should be used if you prefer to use a
   different grid, or need the emissivities computed at constant
   pressure, etc.

1. Obtain the CHIANTI dataset from

   http://www.chiantidatabase.org/

   and install it, say at /foo/bar/CHIANTI/

2. Start IDL and initialize the variables

        WMN=0.0        	;minimum wavelength [Ang] in output database
        WMX=3000.0      ;maximum wavelength [Ang] in output database
        CHIDIR='/foo/bar/CHIANTI/dbase/'
                        ;full path to CHIANTI installation,
			; _including_ the "dbase"
        OUTDIR='/foo/bar/PINTofALE/emissivity/chianti'
                        ;full path to output database location,
                        ; _without_ a trailing "/"

        NE_MIN=8.0      ;minimum log10 density [cm^-3] in database
        NE_MAX=15.0     ;maximum log10 density [cm^-3] in database
        D_NE=1.0        ;grid resolution in log10 electron density

        P_MIN=13.0      ;minimum log10 pressure [cm^-3 K] in database
        P_MAX=20.0      ;maximum log10 pressure [cm^-3 K] in database
        D_P=1.0	        ;grid resolution in log10 pressure (set to -1
                        ;to avoid making constant pressure database)

   These variables set up the IDL script that will extract line
   emissivities from CHIANTI and write them out in a fast-access
   form.  Two directories are created, one containing emissivities
   calculated at constant densities ("chiantiD") and one at constant
   pressures ("chianti").  Since each of these databases take up 176
   MB, in order to save space it may be advantageous to avoid making
   the constant-pressure database.  This may be achieved simply by
   setting D_P=-1.0 in the above initialization.

3. Run the script        MK_LCOOL_CHIANTI

        .run mk_lcool_chianti

   This will take a few hours to complete, but does not need any
   intervention.  The CHIANTI dataset is read in and emissivities
   are computed for each line at a variety of densities, pressures,
   and temperatures, which are then saved in a PINTofALE readable
   format.

4. To compare PINTofALE calculations with CHIANTI's over some
   wavelength range of interest, use the example script chipoacom.
   Start IDL afresh,

	IDL> .run initale
	PoA> v_OUTPS = 'chi42poa.ps'
	PoA> .run chipoacom
   
   The output in the postscript file will show the spectra calculated
   by PINTofALE and CHIANTI, followed by the fractional differences
   between the two.  If all goes well, you should see only horizontal
   green line at Y=0 in the fractional difference plots.

5. CHIANTI has grown considerably over time, and now the full database
   in PINTofALE takes up more than a gigabyte.  This database can be
   compressed to include only locally strong lines -- i.e., lines which
   are within a set threshold (e.g., 1%) of the strongest lines in the
   vicinity (e.g., with 1AA).  The example script chiompress illustrates
   how to extract such lines and write them out to a smaller database.

   	IDL> .run initale
	PoA> chifulldir=!LDBDIR
	PoA> outdir='/foo/bar/emissivity/chiompress'
	PoA> hwdth=1 ;moving window half-width [Angstrom]
	PoA> dynrng=1e2 ;dynamic range threshold within window
	PoA> .run chiompress

   This will create the shrunken line database directory outdirD/ and
   a postscript file that displays which lines were kept and which were
   not, for each element.

   NOTE: Any errors in these computations are due to us, and
   are not the responsibility of the CHIANTI software team.
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