Fluka2008.3b.1

Dear users

Fluka2008.3b.1, a respin of Fluka2008.3b (which is patch release of
Fluka2008.3), has been released today.

The features fixed with respect to Fluka2008.3b.0 are the following:

a) an incorrect isotopic composition for the two Sb (antimony) isotopes
    in the low energy neutron library has been corrected
b) the isotopic composition of hydrogen (1-H versus 2-H) has been
    adjusted so that it is now the one typical for water
c) the natural isotopic composition of all elements has been updated
    to the latest recommendations. Apart a) and b) these are always
    very minor corrections with respect to the past
d) natural Platinum and Lanthanum have been added to the neutron cross
    section library. The two stable Lanthanum isotopes, 138, 139, have
    been processed out of ENDF/B-VIIR0. There is no gamma production
    for both. Natural platinum has been processed out of JEFF-3.1.1,
    no individual isotopes are available: hence no residual nuclei
    infos are available, there are also some kerma issusse, however
    this is the only available evaluation for Platinum to my knowledge
e) it has been added the possibility to use pointwise hydrogen cross
    section together with (grouped) bound hydrogen cross section in the
    thermal region. Until now, using the DEFAULT PRECISIOn, or setting
    WHAT(6)>0 inside LOW-NEUT was switching on pointwise (free gas)
    hydrogen cross sections all over the range 1.E-14 - 0.02 GeV.
    Now setting WHAT(6)=1 keeps the same behaviour, while setting
    WHAT(6)=2 forces the use of hydrogen pointwise (free gas)
    cross sections down to 3.05 eV, while possibly bound grouped
    cross sections are used below. This allows for using pointwise
    cross sections for H as much as possible, while retaining the
    S(a,b) treatment for bound hydrogen in the thermal region.
    This is particularly important for hydrogen bound in water
    (the default hydrogen in the FLUKA neutron cross section library)

At the same time I would like to point out to the Fluka2008.3b release
itself: it occurred at the end of March. I never made the announcement,
sorry for this. The addition with respect to Fluka2008.3 is the
introdcution of bound Compton scattering taking into account all
bound electron levels and hence accounting for Compton Doppler broadening
and binding corrections in a precise way. Only the latter were accounted
for in an approximate way up to now, through the use of the inelastic
form factor S(q,Z). The new treatment is not (yet) activated by default,
please read the release notes if you are interested in activating it.

                  Ciao
                 Alfredo

+----------------------------------------------------------------------+
| Alfredo Ferrari || Tel.: +41.22.76.76119 |
| CERN-EN/STI || Fax.: +41.22.76.69474 |
| 1211 Geneva 23 || e-mail: Alfredo.Ferrari_at_cern.ch |
| Switzerland || |
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Received on Sat Jun 06 2009 - 11:44:35 CEST