Rachel format level scheme file

See also [[rachel_format_matrix_file | Rachel format matrix file]].

Rachel can read both Radware AGS ascii level scheme files and a simple human-readable level scheme file.  The Rachel-format level scheme file is most easily understood from the following example:

<pre>
# Not a real level scheme!
75   184                 # The Z and A number must appear first
band1  0.5  +    0.0     # The ground 1/2+ state at 0 keV
band1  1.5  +  100.0     # The first excited 3/2+ state at 100 keV
band1  2.5  +  200.0
a      2.5  -  250.0     # All states in one band must have the same parity
a      3.5  -  350.0     # The second band will be named "a".
a      4.5  -  450.0
band1  3.5  +  300.0     # States can appear in any order
</pre>

When the file is read into Rachel, a new band is created any time a new band name is encountered.  It is useful to arrange levels in bands to simplify defining initial matrix elements using a rotor model.  (Gosia is not aware of bands.)  

Levels can appear in any order.

Choose short band names (about 8 characters or fewer) to make the level scheme display clearly.  These band names will be referenced in [[rachel_yield_data_files | gamma-ray yield data files]].

Note the following requirements:

All levels with the same band name must have the same parity, or an error will be produced.

There may be only one state of a given spin in a single band.