LOW-PWXS

Summary

sets the correspondence between the Fluka and the pointwise low energy neutron xsec materials

​​

WHAT(1)

isomer code of the target (Z x 10000 + A x 10 + m) Z, A, m, are the atomic, mass and isomer number of the isotope; no default, a value \(< 0\) resets the association to null. If WHAT(1) = 1.0, it is interpreted as to let FLUKA choose the corresponding pointwise cross ection data sets for all isotopes of the elements defined by WHAT(4)-WHAT(6). Warning: uniform grid data sets are not yet supported in the production version

WHAT(2)

if \(> 0\) a uniform grid data set is looked for, 0 (default) means non uniform grid data set, \(< 0\) resets to default, actually 0 or \(< 0\) behave the same.

WHAT(3)

pointwise xsec temperature (def.\(=296\), 0 is ignored, \(< 0\) resets to default), actually 0 or \(< 0\) behave the same

WHAT(4)

= from material “WHAT(4)” …. (def. 3)

WHAT(5)

= …. to material “WHAT(5)” …. (def. WHAT(4))

WHAT(6)

= …. in step of “WHAT(6)” (def. 1)

SDUM

=SDUM10 = extra character for the pointwise cross section file

(default=blank).

=

1-H PWXS \(->\) means the built-in 1-H pointwise cross

sections (no external file needed).

=

2-H PWXS: \(->\) means the built-in 2-H pointwise cross

sections (no external file needed).

=

3-HE PWXS: \(->\) means the built-in 3-He pointwise cross

sections (no external file needed).

=

4-HE PWXS: \(->\) means the built-in 4-He pointwise cross

sections (no external file needed).

=

12-C PWXS: \(->\) means the built-in 12-C pointwise cross

sections (no external file needed).

The file name looked for by FLUKA in the directory

\(\$\)FLUPRO/pwxs is composed as:

\(<\)isomer code\(>\)(-\(<\)extra character if any\(>\))(-uni)-\(<\)temp\(>\).pwx

where -uni is present if WHAT(2) \(>\) 0

Default :

Notes

  1. If pointwise cross sections are requested for a compound the request is ignored. This card works only for elements, nevertheless it will silently ignore possible compounds included in the list defined by WHAT(4)-WHAT(6)

  2. ​ The list of available isotopes and temperatures, as well as of the originating evluated data file can be easily obtained looking in the \(\$\)FLUPRO/pwxs directory

Examples:

31P at 296 K from Endf/b-8r0:
*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+...
LOW-PWXS   150310.0                296.0      P-31      P-31          endfb8r0

All isotopes for all materials at 296 K, leaving Fluka to decide which
evaluations to pick up for each of them:
*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+...
LOW-PWXS   1.0                                 3.0  @LASTMAT