3. DESCRIPTION OF PROGRAM OR FUNCTION
FLUKA is a Fortran 77 (f77) Monte Carlo computer code.
It is a general purpose tool for calculations of particle transport and interactions with matter, covering an extended range of applications spanning from proton and electron accelerator shielding to target design, calorimetry, activation, dosimetry, detector design, Accelerator Driven Systems, cosmic rays, neutrino physics, radiotherapy etc.
For details, see:
G. Battistoni, S. Muraro, P.R. Sala, F. Cerutti, A. Ferrari, S. Roesler, A. Fasso', J. Ranft:
"FLUKA: a multi-particle transport code"
Proceedings of the Hadronic Shower Simulation Workshop 2006, Fermilab 6--8 September 2006, M. Albrow, R. Raja eds., AIP Conference Proceeding 896, 31-49, (2007)
"The FLUKA code: Description and benchmarking" A. Ferrari, P.R Sala, A. Fasso', and J. Ranft, CERN-2005-10 (2005), INFN/TC_05/11, SLAC-R-773
FLUKA is a general purpose Monte Carlo radiation transport code that tracks nearly all particles over an extended energy range. Various generations of FLUKA can be distinguished. Initially (1962-1987) the code, originated at Leipzig University and later modified in collaboration with CERN and Helsinki University of Technology, was transporting exclusively hadrons of energies larger than 50 MeV. The present multi-particle, extended energy code started in 1989 as an effort mainly of INFN (Italy) and has been in continuous development since then, eventually in the frame of a collaboration between INFN and CERN which was formalized in 2003. A complete history is reported on the FLUKA manual, distributed with the code and available on line on the FLUKA web site.
The physical models of FLUKA include hadron-hadron and hadron-nucleus interactions and transport up to 10 PeV, nucleus-nucleus interactions and transport between 10 MeV/n and 10 PeV/n, electron, positron and photon interactions and transport between 100 ev (photons) or 1 keV (electrons and positrons) and 10 PeV, neutrino interactions, neutron multigroup transport and interactions up to 20 MeV, charged particle transport including all relevant processes and transport in magnetic fields.
The program can be run in analog mode or with several variance reduction options. Geometry description can be done with an advanced version of Combinatorial Geometry allowing lattice capabilities and voxel description.
The code has been extensively benchmarked and has found a large number of applications, such as cosmic ray physics, neutrino physics, accelerator design, calorimetry and particle detector simulation, shielding design, dosimetry and radiation protection, space radiation, hadron therapy, neutronics, ADS systems, waste transmutation, etc.
Information about FLUKA development can be found on the web site http://www.fluka.org/
The FLUKA package for LINUX platforms is distributed as two separated files. The release of the FLUKA source code is available under the licence established by the FLUKA Coordination Committee.
The distribution consists in a package containing a compiled library, user routines in source form, INCLUDE files, various unformatted and formatted data files and a number of scripts for compiling, linking and running the program on a given platform. A list of the contents is provided in a README file, and information on the current version, possibly overriding parts of the current manual, may be contained in a file RELEASE-NOTES.
A second package contains the source files.
No external library routines are required. The timing and other necessary service routines are already included.
Changes in FLUKA2011.2 compared to previous version:
Fluka2011.2 contains several new features and additions with respect to Fluka2008.3(b,c,d):
- Stopping power models have been thoroughly reworked, and are now more precise particularly for heavy ions. In particular, the Barkas (Z^3), Bloch (Z^4), and Mott corrections have been implemented.
- Nuclear stopping power is now calculated and taken into account. It matters only for heavy ions at low energies, however it is an essential prerequisite for NIEL and DPA calculations (see next point).
- Radiation damage (Non Ionizing Energy Loss, NIEL, and Displacements Per Atom, DPA) can now be computed and scored. The electromagnetic part is still under refinement, in particular the contributon of bremsstrahlung and pair production has to be implemented, as well as the effect of using the Mott cross section rather than the Rutheford one. The DPA-SCO, NIEL-DEP, and RES-NIEL generalized particles have been added for this purpose.
- The LPM (Landau-Pomeranchuk-Migdal) effect has been extended to pair production (it was already active for bremsstrahlung).
- The lower limit for photon transport has been lowered to 100 eV. Macroscopic surface effects (refraction/reflection) are not treated.
- Several improvements in the hadron-nucleus event generators have been implemented.
- Nuclear deexcitation by photon emission makes use of an extended database of known levels and transitions. The evaporation stage is also consistent with this database.
- The Boltzmann Master Equation, BME, model for heavy ion interactions at low-medium energies is now included in the distributed version. It can handle all projectiles with A>=4 on all targets, with the exception of systems lighter than (alpha, 6Li). BME is invoked for projectile energies lower than 125 MeV/A, however its limit of validity is 150 MeV/A.
- The BME is still in a developing phase, it has been extended and improved very recently, therefore the authors would like to warn users about possible bugs, and would be very grateful to receive feedback about possible problems.
- A new card, IONTRANS has been added to control the transport/interaction of heavy ions. As a consequence, the EVENTYPE card is now obsolete.
- Several new options are now available in order to define spatially distributed sources. Check the manual for the description of the FLOOD, CART-VOL, SPHE-VOL, and CYLI-VOL option in the BEAMPOS card.
- Pre-built source routines for special cases are now supported under the SPECSOUR card. The first one allows an easy setup of colliding beam interactions.
- A pre-built source routine, also available under SPECSOUR, and related auxiliary files and examples, can simulate atmospheric showers from cosmic rays and Solar Particle Events (see the manual for details).
- A new body, a generic quadric QUA, has been introduced in the geometry
- Geometry transformations: directives allowing roto-translations and expansions for sets of bodies are now available in geometry. They can be applied also to the voxel part, when existing.
- The "sophisticated" Compton scattering, including electron binding and Doppler effects is now activated by default for "defaults"CALORIME, PRECISIO, EM-CASCA, or HADROTHE
- A few compounds of dosimetric interest are now available as pre-defined materials, see the manual for details.
- Additional material have been included in the low energy neutron library, some materials have been reworked from newer evaluations, and several materials are now available at 430 K.
- The old 72 groups neutron library has been declared obsolete and is no longer distributed.
- It is now possible to use a different material assignment for thetransport of prompt and radioactive decay radiations. Only switching to vacuum or blackhole is supported, through the ASSIGNMAT card. WARNING for user routines: the array MEDIUM has changed :
MEDIUM (MREG ) --> MEDFLK (I, MREG) I=1 or I=2 for prompt and decay radiation respectively.
- Time scoring has been added for USRYIELD.
- A generalized estimator, NET-CHRG, of net charge (algebraic sum of positive and negative charge) is now available.
- A new dose equivalent estimator, DOSEQLET, based on convolution with the Q(LET) relation as defined in ICRP60 is now available.
- The #include directive is now supported in the input file.
- There is no longer a default material assignment. Previously BLCKHOLE was assigned to all regions, except for region 2 which was assigned COPPER. Now the program stops whenever a region has no material assigned.
Most of the physics improvements are brand new and still unpublished.
This version should not be used to publish results about individual model validation/benchmarking (see the license), in particular but not only when the new features are concerned.In case of doubt please contact the FLUKA Collaboration Committee, through firstname.lastname@example.org.