The FLUKA Code

The FLUKA CodeAn Introduction to FLUKA:a multipurpose Interaction and Transport MC codeBeginners’ FLUKA Course

FLUKAMain authors:A. Fassò, A. Ferrari, J. Ranft, P.R. SalaContributing authors: G. Battistoni, F. Cerutti, M. Chin,T. Empl, M.V. Garzelli,M. Lantz, A. Mairani, V. Patera, S. Roesler, G. Smirnov,F. Sommerer, V. VlachoudisDeveloped and maintained under an INFN-CERNagreement Copyright 1989-2011 CERN and INFN 4000 usershttp://www.fluka.org

The FLUKA international CollaborationV. Boccone, T. Boehlen, M. Brugger, F. Cerutti, M. Chin, Alfredo Ferrari, A. Mereghetti, S. Roesler, G. Smirnov,C. Theis, R. Versaci, Heinz Vincke, Helmut Vincke, V. Vlachoudis, J.Vollaire, CERNA. Fassò, Jefferson Lab, USAJ. Ranft, Univ. of Siegen, GermanyG. Battistoni, F. Broggi, M. Campanella, F. Cappucci, E. Gadioli, S. Muraro, P.R. Sala, INFN & Univ. Milano, ItalyL. Sarchiapone, INFN Legnaro, ItalyG. Brunetti, A. Margiotta, M. Sioli, INFN & Univ. Bologna, ItalyV. Patera, INFN Frascati & Univ. Roma La Sapienza, ItalyM. Pelliccioni, INFN Frascati & CNAO, Pavia, ItalyM. Santana, SLAC, USAA. Mairani, CNAO Pavia, ItalyM.C. Morone, Univ. Roma II, ItalyK. Parodi, F. Sommerer, HIT, Heidelberg, GermanyA. Empl, L. Pinsky, B. Reddell, Univ. of Houston, USAK.T. Lee, T. Wilson, N. Zapp, NASA-Houston, USAS. Rollet, AIT, AustriaM. Lantz, Uppsala Univ., SwedenG. Lukasik, PolandM.V. Garzelli, Granada Univ., SpainS. Trovati, PSI, SwitzerlandP. Colleoni, Bergamo, ItalyAnna Ferrari, FZR Rossendorf, Germany

RFFLUKA ApplicationsMomentunCleaningCMSPoint 4Point 5LHC DumpPoint 3.3Point 3.2The LHCLoss RegionsPoint 6Regions of high losses(e.g., Collimators, ) Regions with low losses(e.g., due to residual gas)Point 7BetatronCosmic ray physicsCleaningALICENeutrino physicsLHCbAccelerator design ( n ToF, CNGS, LHC systems)ATLASParticle physics: calorimetry, tracking and detector simulation etc.( ALICE, ICARUS, .)ADS systems, waste transmutation, ( ”Energy amplifier”, FEAT, TARC, )Shielding designDosimetry and radioprotectionSpace radiationHadrontherapyNeutronicsPoint 2Point 8Point 1

The HistoryThe beginning:The name:The early days1962: Johannes Ranft (Leipzig) and Hans Geibel (CERN):Monte Carlo for high-energy proton beams1970: study of event-by-event fluctuations in a NaIcalorimeter (FLUktuierende KAskade)Early 70’s to 1987: J. Ranft and coworkers (Leipzig University) with contributionsfrom Helsinki University of Technology (J. Routti, P. Aarnio) and CERN(G.R. Stevenson, A. Fassò)Link with EGS4 in 1986, later abandonedThe modern code: some datesSince 1989: mostly INFN Milan (A. Ferrari, P.R. Sala): little or no remnants ofolder versions. Link with the past: J. Ranft and A. Fassò1990: LAHET / MCNPX: high-energy hadronic FLUKA generator No further update1993: G-FLUKA (the FLUKA hadronic package in GEANT3). No further update1998: FLUGG, interface to GEANT4 geometry2000: grant from NASA to develop heavy ion interactions and transport2001: the INFN FLUKA Project2003: official CERN-INFN collaboration to develop, maintain and distribute FLUKA

The FLUKA Code design - 1Sound and updated physics modelsBased, as far as possible, on original and well-tested microscopic modelsOptimized by comparing with experimental data at single interactionlevel: “theory driven, benchmarked with data”Final predictions obtained with minimal free parameters fixed for allenergies, targets and projectilesBasic conservation laws fulfilled “a priori” Results in complex cases, as well as properties and scaling laws,arise naturally from the underlying physical models Predictivity where no experimental data are directly availableIt is a “condensed history” MC code, with the possibilityuse of single instead of multiple scattering

The FLUKA Code design - 2Self-consistencyFull cross-talk between all components: hadronic,electromagnetic, neutrons, muons, heavy ionsEffort to achieve the same level of accuracy:for each componentfor all energies Correlations preserved fully within interactions andamong shower componentsFLUKA is NOT a toolkit! Its physical models are fullyintegrated

The Physics Content of FLUKA 60 different particles Heavy Ions Nucleus-nucleus interactions from Coulomb barrier up to10000 TeV/n Electromagnetic and μ interactions 1 keV – 10000 TeV Hadron-hadron and hadron-nucleus interactions 0–10000 TeV Neutrino interactions Charged particle transport including all relevant processes Transport in magnetic fields Neutron multigroup transport and interactions 0 – 20 MeV Analog calculations, or with variance reduction

The FLUKA course: an IntroductionHow:This course is intended to provide users with the basic (andpossibly more than basic!) knowledge of:a)The most relevant FLUKA instructions and optionsb)The physics models adopted in FLUKAc)The different scoring options embedded in FLUKAd)The different running optionse)How to insert user code in FLUKAf)The tools to plot resultsg)The right approach to the existing documentationh)The procedures to overcome difficulties and problemsand related debugging toolsi)etc. etc.

Method There will be formal lectures but they will befollowed as much as possible by practical (simple)examples. Emphasis will be given to practice. If possible we shall try to transform your questionsinto cases of general interest.

A possible problem People here are not at the same level of FLUKAknowledge. There are those who already have someexperience, maybe not negligible. However we need to start from scratch. We apologize to the experienced people and begthem to be patient: it’s not excluded a priori thatthey can learn something new also concerning thevery basic elements!

A glimpse of FLUKA

The FLUKA versionFLUKA20xx.n(y)(.m)Major versionRespinMinor version PatchlevelSince 2006 each version is going to be maintained for 2 years max.In this course we are using FLUKA2011.1

The FLUKA license (it is not GPL): Standard download: binary library user routines. FLUKA can be used freely for scientific and academic purposes,ad-hoc agreement for commercial purposes It cannot be used for weapon related applications It is not permitted to redistribute the code (single user, singlesite) User can add their own scoring, sources etc through a wide set ofuser routines, provided they don’t modify the physics Relevant references for each FLUKA version can be found in thedocumentation It is possible, by explicit signature of license, to downloadthe source for researchers of scientific/academic Institutions.(!!! now from NEA as well !!!) FLUKA cannot be copied, even in part, into other codes, ortranslated into another language without permission. The user cannot publish results with modified code, unless explicitauthorization is granted in advance.14

Using FLUKAPlatform: Linux with g77Under test: Linux and Mac OSX (gfortran), Windows-Cygwin (g95)The code can be compiled/run only on with operating systems, compilers (andassociated) options tested and approved by the development teamStandard Input: Command/options driven by “data cards” (ascii file) .Graphical interface is available!!!! Standard Geometry (“Combinatorial geometry”): input by “data cards” Standard Output and Scoring:Apparently limited but highly flexible and powerfulOutput processing and plotting interface available

The FLUKA mailing lists fluka-users@fluka.orgUsers are automatically subscribed here when registering onthe web site. It is used to communicate the availability of newversions, patches, etc. fluka-discuss@fluka.orgUsers are encouraged to subscribe at registration time, butcan uncheck the relevant box. It is used to have user-userand user-expert communication about problems, bugs, generalinquiries about the code and its physics contentusers are strongly encouraged to keep this subscription

FLUKA DescriptionFLUKA is a general purpose tool for calculations of particle transportand interactions with matter, covering an extended range ofapplications: from proton and electron accelerator shielding to targetdesign, calorimetry, activation, dosimetry, detector design, AcceleratorDriven Systems, cosmic rays, neutrino physics, radiotherapy etc. 60 different particles Heavy Ions Hadron-hadron and hadron-nucleus interaction ”0”-10000 TeVElectromagnetic and μ interactions 1 keV – 10000 TeVNucleus-nucleus interaction up to 10000 TeV/nCharged particle transport and energy lossNeutron multi-group transport and interactions 0-20 MeVn interactionsTransport in magnetic fieldCombinatorial (boolean) and Voxel geometriesDouble capability to run either fully analogue and/or biased calculationsOn-line evolution of induced radioactivity and doseUser-friendly GUI interface thanks to the Flair interfaceMaintained and developed under CERN-INFN agreement and copyright1989-2011More than 4000 users all over the world http://www.fluka.org

Examples of FLUKA Applications

The TARC experiment at CERN:

The TARC experiment: neutron spectraFLUKA EA-MC (C.Rubbia et al.)

Applications – LHC collimation regionRFMomentunCleaningCMSPoint 4Point 5LHC DumpPoint 3.3Point 3.2The LHCLoss RegionsMagnetsPoint 6Regions of high losses(e.g., Collimators, )Point 2Regions with low losses(e.g., due to residual gas)Point 7BetatronCleaningPoint 8ALICEPoint 1LHCbATLASCollimatorsFLUKA geometryvisualized withSimpleGeo

Example: 3 Primary Collimators IR722

Studies of the radiation damage to the LHCcopper collimatorsEstimated number of DPAper incident proton (beamsize accident case) on acopper jaw

Applications – LHC collimation regionCooling timeResidual dose rate (mSv/h)after one year of operation8 hours1 week4 monthsCERN-SC-2005-092-RP-TN6th FLUKAcourse,ParisCERN 20087th FLUKAcourse,Sept.2424

Applications – CNGS

Cern Neutrino to Gran SassoEngineering and physics: target heating,shielding, activation, beam monitors, neutrino spectraMuons in muon pits: horiz. distribution for beam alignmentEnergy deposition in CNGS target rods, GeV/cm3/pot

Applications – CNGSmSv/hExample:100tcool 1 day1016th FLUKA course, CERN 2008

Effect of a magnetic muonspoiler in the LCLS tunnelThe spoiler allows to reducethe shielding thickness in theforward direction.dose rate map without spoilerthe same with spoilerMagnetic field map used by FLUKA

Damage to electronicsSLAC: Damage to electronics near the dumps atthe LCLS (Linear Coherent Light Source)

CERN-EU High-Energy Reference Field facility (CERF)Thermo-Eberline dose-meter FHZ 672samples in contactwith a 50 cm long, 7cm diameter coppertarget, centred onthe beam axisMicrospec

Test of instrumentation : Beam Loss Monitors at CERFCERN-EN-NOTE-2010-002-STICERF setupBLM’s positions

CERF particle spectraNeutron spectrach hadronsCh. Had.andBLM1Ch HadandBLM 6

(3D) Calculation of Atmospheric ν FluxThe first 3-D calculation ofatmospheric neutrinos wasdone with FLUKA.The enhancement in thehorizontal direction, whichcannot be predicted by a 1-Dcalculation, was fullyunexpected, but is nowgenerally acknowledged.In the figure: angulardistribution of ,,,In red: 1-D calculatione,e .

Negative muons at floating altitudes: CAPRICE94Open symbols: CAPRICE dataFull symbols: FLUKAprimary spectrum normalization AMS-BESSAstropart. Phys., Vol. 17, No. 4 (2002) p. 477

Neutrons on the ER-2 plane at 21 km altitudeMeasurements:Goldhagen et al., NIM A476, 42 (2002)Note one order of magnitudedifference depending on latitudeFLUKA calculations:Roesler et al., Rad. Prot. Dosim. 98,367 (2002)

Dosimetry ApplicationsRoesler et al.,Rad. Prot. Dosim.98, 367 (2002)Ambient dose equivalent from neutrons at solar maximum oncommercial flights from Seattle to Hamburg and from Frankfurt toJohannesburg.Solid lines: FLUKA simulation

Dosimetry applications: doses toaircrew and passengersToilet orGalleyAIRBUS 340Wing fuel tankCockpitFerrari et al, Rad. Prot.Dosim. 108, 91 (2004)Business ClassEconomic ClassCenter fuel tankHold