Dear Fluka Users,
I have the pleasure to announce a new major FLUKA release.
fluka2020.0beta is now available on the www.fluka.org website
This brand new release includes plenty of improvements and new
features, which, while they have been extensively tested and debugged,
could still be subject to residual hidden problems, hence the "beta"
appellation. Therefore, for a few weeks both fluka2011.2x.8 and
fluka2020.0beta will available on the web site, and assistance will be
provided for both. Please SPECIFY WHICH VERSION you are using,
possibly in the subject, when asking for help at
fluka-discuss_at_fluka.org.
The changes with respect to fluka2011.2x.8 are reported in the
release notes included below (also on the website and within the fluka
distributions)
Copyright and licensing conditions have changed too, the website will
automatically ask you to accept them before downloading. Users who
already asked access to the source code will simply have to reconfirm
acceptance of the license: they will receive a message with details.
A corresponding Flair version will be released soon.
The Fluka team
- Release notes for Fluka2020.0beta -
This is a major release with several important physics and technical
improvements and additions.
This fully brand new release includes a plethora of improvements and new
features, which, while they have been extensively tested and debugged,
could still be subject to some residual hidden problem, hence the "beta"
appellation. For this reason, for a few weeks both fluka2011.2x.8 and
fluka2020.0beta will available on the web site, and assistance will
be exceptionally provided for both. Please SPECIFY WHICH VERSION you
are using, possibly in the subject, when asking for help at
fluka-discuss_at_fluka.org.
Please take note of the revised license, which you can find in the
LICENSE.2020.0beta file, or printed by the code when it runs.
The most relevant new features are described below, those flagged "(#)"
are either particularly complex, or brand new, and therefore more
prone to possible residual rare issues
-- PHYSICS IMPROVEMENTS: --
- The PEANUT model has been significantly improved in the energy range
from a few GeV's on. Comparisons with experimental data for
production in the 10-20 GeV range shows noticeable improvements
in the predicted distributions, particularly for heavy targets. The
introduction of cross section fluctuations now allows better
predictions of multiplicity distributions of fast hadrons in the
multi-GeV regime, with impact on computed calorimeter resolutions (#)
- Electro-nuclear reactions are now implemented and can be activated with
the PHOTONUC card with sdum=ELECTNUC (see the manual for further details)
- Muon-nuclear reactions are now extended down to virtual photon energies
in the quasi-deuteron and Giant Dipole Resonance regions with significant
improvements in the predictions of cosmogenics backgrounds
- Electro-Magnetic-Dissociation has been inproved introducing also
the Electric Quadrupole (E2) contribution, of particular importance
at the lowest energies
- An extended and improved nuclear database allows better treatment
of unstable nuclei near the neutron and proton drip lines.
Masses, decay channels and branching ratios have been extensively
revised. Many more isomers are now included in the database:
conventionally FLUKA considers "isomers" all excited states with
half-lives in excess of 1 microsecond. Please note that residual
nuclei output files from previous versions cannot be processed
with the fluka2020.0 auxiliary routines, because of their dependence
on the nuclear database.(see below)
- The inclusion of many more isomers makes the old, crude, 50-50%
estimate for isomer vs ground state production rather questionable.
That estimate, applied a posteriori and only for activation and
residual dose rate purposes, becomes more and more unphysical,
particularly for nuclei with more than one isomer (eg a nucleus with
3 isomers would be scored on a 25-25-25-25% basis). An attempt
to evaluate isomer production "a priori" during the nuclear model
evolution is now implemented. It is still rudimentary, but it should
be already better than the old ansatz. Together with the isomer
production data now available in the neutron cross section file
(see below), it should significantly improve isomer production
predictions. It should be noted that now isomers, when produced,
are allowed to fly until stopping, since their half-life is such
that they will hardly decay before stopping in most practical
problems. The new isomer production mechanism can be switched
off (strongly discouraged) by setting What(1)=-1 in a PHYSICS
card with sdum=ISOMERS (#)
- A deuteron pre-formation production mechanism by light nuclei has been
implemented, resulting in much better predictions of excitation
functions of reactions like (p,d)/(p,pn), (n,d)/(n,np) on light nuclei
at low and intermediate energies. This mechanism is automatically
activated if the user requests COALESCEnce (PHYSICS card) as
recommended
- Direct reactions to IAS (Isobar Analogue State) have ben implemented
for a few isotopes of particular importance as neutron producing
targets, resulting in major improvements in the prediction of
neutron spectra at forward angles at low to medium energy (#)
- Full account for discrete levels, out of the (IAEA) Ripl-3 library,
is now implemented in every nuclear reaction step/generator
- Heavy fragment evaporation up to Z_max=4, A_max=9, is now automa-
tically activated when the PRECISIOn default is selected. For
residual nuclei activation and/or dose rates it is recommended
to activate heavy fragment evaporation up to the maximum Z and A
implemented (eg with what(1)=3.0 in the PHYSICS card with sdum
EVAPORATion)
- A simplified model for angular momentum barriers is now implemented
inside the Fermi break-up de-excitation model whenever emission
cannot occur with L=0. Major improvements in residual nuclei
predictions for virtual or real photons on light nuclei in the
GDR region had been observed thanks to this extension
- Photofission is back working in reasonable shape
- The high energy fission model has been improved. Further work on
this topic is scheduled in the near future
- Fission fragment yields by low energy neutrons (neutrons below 20 MeV)
are now based on the most recent evaluations, Endf/b-VIIIr0,
Jeff-3.3, and Jendl-4.0
- Neutron cross sections for several isotopes had been updated with
more recent evaluations, mostly Endf/b-VIIIr0. The Tellurium cross
sections have been added (see the manual for further details).
As a consequence of the availability in Endf/b-VIIIr0 of some isotopes
previously missing (eg 13C, 17O, 18O) the FLUKA identifier for some
elements are now different (eg for OXYGEN), please refer to the
manual for further details
- Neutron cross sections now contain the information for production of
isomers, out of the European Activation File. Therefore isomer
versus ground state production by low energy neutrons is no longer
based on the "old", crude, estimate 50-50%, but it is rather calculated
according to the evaluated values when available (#)
- Fully correlated pointwise cross sections are now available for
neutrons below 20 MeV for 2-H, 3-He, 4-He and 12-C (in addition
to 1-H and 6-Li which were already implemented). They are
automatically selected when What(6) of LOW-NEUT is set to a suitable
value (see the manual), or by default for some DEFAULTS, if the
material name is respectively DEUTERIUM, HELIUM-3, HELIUM-4,
CARBON/C-12/12-C/C-NAT/NAT-C (all 5 are recognized for Carbon)
- (Anti)Neutrino cross sections have been revised and improved,
particularly at the higher energies, and for charm production
- A preequilibrium step, based on the PEANUT one, has been introduced in
the rQMD event generator. Together with other improvements this results
in significantly better reproduction of ion-ion experimental data,
particularly towards the bottom energy range of application of rQMD
- A preequilibrium step, based on the PEANUT one, has been introduced in
the BME event generator when the projectile-target/pre-fragment
combination is not one of those pre-calculated in the BME database.
This addition results in significant improvements particularly for
(very) light projectiles on heavy targets. There are still some
weaknesses for intermediate-to-heavy projectiles on
intermediate-to-heavy targets, with BME somewhat overpredicting
ejectile high energy tails
- Alpha-Nucleus cross sections for light nuclei have been updated
according to the recent expreimental data, bringing better agreement
with measured attenuation curves and Bragg peaks
- A special treatment has been implemented for some exo-energetic,
low energy reaction cross sections, in particular p-11B, Alpha-18O,
Alpha-17O, Alpha-13C
- Default damage threshold energies when asking DPA estimates are now
available for all elements. The user can still override them by
inputting her/his own values. Please note that widely different values
are sometimes available in the literature for the same element, hence
care must be used when using these default values. Also they apply
to elements, for compounds/mixtures no specific default is available
- Explicit emission of Alpha particles is now included in the radioactive
decay part, for isotopes whose alpha decay energies and branchings
are known.
-- TECHNICAL IMPROVEMENTS --
- Dynamic memory allocation for the blank common is now supported
in the Gfortran versions. The code allocates a preset memory size
and automatically increases it whenever a USRBIN/EVENTBIN or VOXEL
card so requires. If the available memory is exhausted somewhere
else (i.e. geometry), or anyway is she/he so wishes, the user can
ask for a larger preset (blank common) memory by selecting
a proper value with What(6) in the GLOBAL card. Max ~4GB.
- The maximum region number is now set at 100000 for the G77 version,
while it is "unlimited" for the Gfortran version thanks to the
dynamic memory allocation. For both versions all region number
dependent arrays are now allocated in blank common according to
the actual number of regions, with the exception of one, dynamically
allocated by Gfortran and statically set to 100000 for G77 (#)
- The SPOTBEAM, SPOTDIR, SPOTPOS, and SPOTTRAN cards allow
treatment planning system like multi-energy/position beams to
be used (see the manual for further details)
- The special SPECSOURce sdum BIN-SOUR can be used to create a spatially
distributed source out of a USRBIN file (eg a radioactive isotope
distribution, see the manual for further details)
- The Earth magnetic field according to the latest (December 2019)
release of the International Geomagnetic Reference Field (Igrf13)
has been implemented into the code and it is an option for space
and cosmic ray calculations
- The PYX, PYY, PYZ (PYramid along X, Y, or Z axis) bodies have been
added to the geometry (#)
- Up to two nested roto-translations are now allowed in geometry, both
for bodies and lattices (see the manual, in particular the new
option LATTSNGL, for details)
- Parentheses in region definitions are now evaluated run time, if the
initialization time expansion results in too many terms
- The rQMD event initialization has been made significantly faster,
resulting in speed-up factors up to x3 for light projectiles
- Hadron masses and physical constants have been updated to the values
reported in the PDG 2018 edition
-- IMPORTANT WARNINGS FOR THE USERS --
We would like to stress once more that whenever activation is a concern or,
"precise" particle production calculations are required, the PEANUT extended
model, as well as heavy particle evaporation/fragmentation and coalescence
should be switched on (see below for details)
- Already starting from Fluka2006.3, a new high energy event generator had
been developed, based on the sophisticated nuclear physics of PEANUT
coupled with the proved FLUKA Dual Parton Model description for
hadron-hadron collisions and a brand new Glauber cascade treatment.
Starting
from fluka2011.2x release, this model is substituting as default the old
one
(PEANUT was already the default below 5 GeV).
All thin target benchmarks of the code by the development team are run
with the new model, the development of the old one being frozen. Only
this model should be considered representative of the ultimate FLUKA
performances. The PHYSICS card with SDUM PEATHRESH allows to switch back
to the old model (highly discouraged)
Also the new model potentially provides a fully featured simulation of
high energy quasi-elastic events, but this requires cleaning up some FLUKA
inconsistencies and therefore is not yet activated.
- Whenever residual nuclei (and residual dose rates) scoring is of
importance, or accurate neutron yields are required, the heavy residual
emission ("fragmentation") and the coalescence emission of fast complex
particles should be switched on, through the following data cards:
PHYSICS 3.0
EVAPORAT
PHYSICS 1.0
COALESCE
and (as a consequence of coalescence) it would be wise to link with
rQMD-2.4 (and DPMJET) and activate ion transport and interactions. These
suggestions are mandatory for residual nuclei calculations.
Those options are not on by default because the heavy evaporation carries a
big CPU penalty which would be a waste for most problems when residuals are
not a issue. Starting from Fluka2020.0, heavy evaporation is on by
default (limited to A_max=9, Z_max=4) when the PRECISIOn default is
requested
- The ARB, BOX, WED body types, which are deprecated since many years due to
their precision problem prone coding, are now accepted only if the user
explicitly sets SDUM=DEPRBODY in the GLOBAL card. They will disappear
entirely
with the next full release. The same geometrical shapes can be obtained in
a safer way using a combination of the other body types and of
transformations.
- !!!! MAJOR WARNING, please read !!!!
The use of so-called "expressions" inside the Flair preprocessor, those
writing pseudo-comments in the input file like
!_at_what.1=-1.5e-2
has been found to be prone to potentially dangerous situations, where
FLUKA runs with parameters different from those intended by the user with
no detectable warning. This is particularly true if a Flair generated
input is modified by editing it outside Flair or viceversa, or in all
cases where inputs using the #include directive together with those kind
of expressions or similar operators are modified in Flair.
The developer team has identified already a few scenarios where because of
these shortcomings of the Flair implementation, FLUKA could run with a
setup different from the one shown in the Flair screen.
Therefore it is STRONGLY recommended to refrain from using such Flair
features until a safer implementation will be available (the developer
team is working on it). If you cannot avoid using those features, please
ALWAYS CHECK what ended up into the input file (and the corresponding
interpretation in the output file), since what will be actually
run is what is written in the WHATs fields of the
input file (!... comments ignored) and not what the Flair screen can
show in case they are different. Warnings have been added in the .err
and .out files for this purpose.
In order to still use those kind of expressions, the user has to
explicitly set SDUM=OLDFLAIR in the GLOBAL card. If by chance, a user
needs to use those expressions AND some deprecated body types
(see the previous warning) at the same time, the special SDUM=OLDFLBDY
is available for this purpose
Please note that FLUKA offers the possibility to code expressions
*DIRECTLY IN THE INPUT FILE*, through the #define directive.
-- Modifications to user-written source.f routines
Due to the new treatment of isomeric states, three new variables have
to be initialized in the stack: EEXSTK, TMNSTK, ILVSTK.
Users should modify their custom source.f routines accordingly,
setting the variables as in the new source.f template.
-- Old residual nuclei output files
As described above, the auxiliary programs (usrsuw and usrsuwev in
$FLUPRO/flutil) that sum and process the residual nuclei output files
depend on the nuclear database. Users who still need to process files
produced with previous fluka versions can do it by keeping their
fluka2011.2x distribution. Users who already produced xxx_tab.lis
and xxx_sum.lis files are not concerned.
-- PLATFORMS UNDER WHICH FLUKA SHALL BE RUN --
This version of the code should be run on the platforms for which it
has been released, that is Linux x86 under g77 (which runs on both
32 and 64 bit machines) and Linux x86_64 under gfortran. The latter
requires a recent version of the gfortran compiler, given the
incompatibility between different versions of gfortran.
A Mac OS version compiled with gfortran is also available.
The available gfortran versions are compiled with gfortran 9.2 (Linux) and
gfortran 9.2 (Mac). Files compiled with gfortran 8.4 (Linux) and
gfortran 8.3 (Mac) are also available.
Users running on Windows can install fluka in a virtual machine through the
provided dockers scripts (on the website).
The code has been reasonably checked and validated for these
platforms/compilers only. There is no warranty whatsoever that the
code and/or the compilers used are bug free, see the disclaimer in the
license file for further details.
The availability of the source code shall not be exploited for tentative
builds on other architectures or with different compilers/compiler options
than the ones recommended by the development team. Our experience shows that
for a code of the complexity of FLUKA the chances of hitting one or more
compiler issues are pretty high. Therefore users shall not make use
for every serious task, including whichever form of publication or
presentation, of code versions built on platforms and/or with compiler
options which have not been cleared as safe by the development team.
-- INSTRUCTIONS FOR THE GFORTRAN VERSION --
The gfortran (64 bits) version is for x86_64 machines and cannot be run
on 32 bit architectures. The FLUKA scripts recognize which version the
user is running according to the following:
a) The FLUFOR environmental variable, which can take the values "g77"
or "gfortran"
b) If FLUFOR is not set, if the directory name contain the "gfor" string
gfortran is assumed, g77 otherwise
c) If gfortran is selected by means of a) or b), the additional variable
GFORFLU can be set to specify the specific version of gfortran to be
used if more than one is available. Please note that gfortran >= 6.3
is required. For example, if on your machine "gfortran" points to a
version < 6.3, and "gfortran63" points to version 6.3, you can set
GFORFLU to "gfortran63" and happily use the FLUKA gfortran (64 bits)
version
-- FLUKA AND LICENSING CONDITIONS --
Use of FLUKA must be compliant with the FLUKA user license, which is
not a GPL-like license. Therefore, users shall read carefully the
licensing conditions as available in the distribution tar file,
on the FLUKA website and in the output files.
In case of doubts or need for special authorizations, or anyway for
licensing and commercial questions, or questions related to publications
or releases, users shall contact the Fluka Scientific Committee (FSC)
(fsc_at_fluka.org) .
-- REFERENCES TO BE QUOTED --
The use of the FLUKA code must be acknowledged explicitly by quoting
at least two of the following set of references
- T.T. Bohlen, F. Cerutti, M.P.W. Chin, A. Fasso`, A. Ferrari, P.G.
Ortega,
A. Mairani, P.R. Sala, G. Smirnov, and V. Vlachoudis,
"The FLUKA Code: Developments and Challenges for High Energy and
Medical Applications", Nuclear Data Sheets 120, 211-214 (2014)
- A. Ferrari, P.R. Sala, A. Fasso`, and J. Ranft,
"FLUKA: a multi-particle transport code",
CERN 2005-10 (2005), INFN/TC_05/11, SLAC-R-773
Use of Flair must be acknowledged using the following reference:
- V. Vlachoudis, Proc. Int. Conf. on Mathematics, Computational
Methods & Reactor Physics (M&C 2009), Saratoga Springs, New York, 2009
Additional FLUKA references can be added, provided they are
relevant for the problems under consideration, in particular
the use of some specific models should be individually acknowledged, eg:
For the use of the neutrino event generator (NUNDIS):
- G. Battistoni, A. Ferrari, M. Lantz, P. R. Sala and G. I. Smirnov,
"A neutrino-nucleon interaction generator for the FLUKA Monte Carlo
code",
Proceedings of 12th International Conference on Nuclear Reaction
Mechanisms, Varenna, Italy, 15-19 June 2009,
CERN-Proceedings-2010-001 pp.387-394.
For the use of (the modified) rQMD-2.4:
- H. Sorge, H. Stoecker, and W. Greiner, Annals of Physics 192, 266
(1989)
- V. Andersen. F. Ballarini, G. Battistoni, M. Campanella, M. Carboni,
F. Cerutti, A. Empl, A. Fasso`, A. Ferrari, E. Gadioli, M.V. Garzelli,
K. Lee, A. Ottolenghi, M. Pelliccioni, L.S. Pinsky, J. Ranft, S.
Roesler,
P.R. Sala, and T.L. Wilson,
"The FLUKA code for space applications: recent developments"
Advances in Space Research, 34(6), 1302-1310 (2004).
For the use of DPMJET-3:
- S.Roesler, R.Engel, J.Ranft: "The Monte Carlo Event Generator
DPMJET-III"
in Proceedings of the Monte Carlo 2000 Conference, Lisbon, October
23-26
2000, A. Kling, F. Barao, M. Nakagawa, L. Tavora, P. Vaz eds.,
Springer-Verlag Berlin, 1033-1038 (2001).
- A. Fedynitch, PhD Thesis,
https://cds.cern.ch/record/2231593/files/CERN-THESIS-2015-371.pdf
For medical applcations of FLUKA:
- G. Battistoni, J. Bauer, T.T. Boehlen, F. Cerutti,
M.P.W. Chin, R. Dos Santos Augusto, A. Ferrari, P.G. Ortega,
W. Kozlowska, G. Magro, A. Mairani, K. Parodi, P.R. Sala, P. Schoofs,
T. Tessonnier, V. Vlachoudis,
"The FLUKA code: An accurate simulation tool for particle therapy",
Frontiers in Oncology, Radiation Oncology Section, 00116 (24 pages)
(2016)
Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
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Received on Fri Jan 17 2020 - 12:09:35 CET