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New developments in FLUKA Paola Sala INFN Milano On behalf of the FLUKA collaboration ≈ 50 members from several institutions around the world Varenna,

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Presentation on theme: "New developments in FLUKA Paola Sala INFN Milano On behalf of the FLUKA collaboration ≈ 50 members from several institutions around the world Varenna,"— Presentation transcript:

1 New developments in FLUKA Paola Sala INFN Milano On behalf of the FLUKA collaboration ≈ 50 members from several institutions around the world Varenna, June 14 th 2012

2 A glimpse of latest developments and applications FLUKA is a general purpose tool for calculations of particle transport and interactions with matter (all hadrons, ions, EM) FLUKA applications range from LHC or cosmic energies down to hadron-therapy (A. Mairani’s talk) and microdosimetry Standard tool at CERN for beam-machine interactions and radioprotection A long and constant development of nuclear interaction models that benefits to a wide range of applications Without forgetting EM and particle transport In this talk some news on Hadronic interactions in the few GeV energy range and neutrinos Interactions of  particles below 150 MeV/A Improvements in the latest stages of nuclear reactions with examples Very high energy : examples of LHC applications June 14th, 2012Paola Sala, Varenna20122

3 Hadron interactions in FLUKA: an integrated ensemble h-h DPM + quark chain hadronization Resonance production and decay Elastic, ch.exc. h-A PEANUT Glauber-Gribov multiple collisions G-INC Preequilibrium (Exciton) Evaporation/Fragmentation or Fermi Break-up  deexcitation A-A DPMJET3rQMD-2.4BME Muon photonucNeutrinoEm-dissociationPhotonuclear June 14th, 2012Paola Sala, Varenna20123

4 DualPartonModel at its lower limit Strong experimental effort is ongoing on particle production from beams in the few to tens of GeV range Important for neutrino beams and interactions Challenging: too high energy for resonance formation, too low for quark gluon based models Fluka high energy hadron-hadron interaction model – DPM-: chain production and chain hadronization Strong mass effects for low energy chains  “standard” hadronization outside its validity region NEW: gradual transition of low energies chains to “phase space explosion” constrained in p T, including baryons, mesons, resonances. June 14th, 2012Paola Sala, Varenna20124

5 Neutrino interactions (ICARUS..): 5Paola Sala, Varenna2012June 14th, 2012 Fluka has its own neutrino interaction generator, including QE, Resonance, DIS DIS uses the same chain hadronization as DPM Embedded in the FLUKA nuclear environment (PEANUT) New low-mass chain treatment-> improvements in the RES-DIS transition μ +p -> μ - +p+  +

6 Pion production close to DPM thr. 6Paola Sala, Varenna2012June 14th, 2012 Pion production from proton interactions on Be at 12.3 GeV Emitted pion spectra at different angles in the range Dots: data (BNL910 expt.), histograms : Fluka -- ++

7 Pion production close to DPM thr. 7Paola Sala, Varenna2012June 14th, 2012 Pion production from proton interactions on Be at 17.5 GeV Emitted pion spectra at different angles in the range Dots: data (BNL910 expt.), histograms : Fluka -- ++ ++

8  -induced reactions,  -emitters Fragmentation tail in hadrontherapy beams Radiation damage to electronics Production of residual nuclei: On heavy targets, interactions of secondary  ’s can produce dangerous radioisotopes, for instance:  ( , Bi )  At : chemically reactive (halogen)  and  + emitters. Eg, At has a mean life of 8.1 h, 5.6 MeV  decay and  decay to Po  ( , Pb )  Po...well known “problematic”  -emitters Some of these isotopes have exemption limits 3-4 order of magnitudes smaller than most other radioisotopes commonly produced at accelerators  New  New in FLUKA:  - induced reactions at low energy (E < 150 MeV/A) through the BME model  At higher energies: already handled through the rQMD-2.4 and DPMJET-3 models June 14th, 20128Paola Sala, Varenna2012

9 9 FLUKA: the BME Model for nucleus – nucleus interactions below 150 MeV/n FLUKA The BME ( Boltzmann Master Equation) in FLUKA It works for A proj,A targ  4, E  150 MeV/A 1. COMPLETE FUSION 2. PERIPHERAL COLLISION three body mechanism with incomplete fusion one nucleon break-up and possibly transfer (at high b) pickup/stripping (for asymmetric systems at low b) The kinematics is suggested by break-up studies. Fragment(s) : pre-equilibrium de-excitation according to the BME theory (where available) or to the PEANUT exciton model evaporation/fission/fragmentation/ gamma de-excitation, same as for hadron-nucleus interactions June 14th, 2012Paola Sala, Varenna2012 BME : E. Gadioli group in Milano

10 BME in FLUKA : ( ,xn) examples Excitation functions for the production of radioisotopes from  interactions on Au (left) and Pb ( right) (Data: CSISRS, NNDC) June 14th, Paola Sala, Varenna2012

11 Gamma De-excitation in Fluka At the end of evaporation : cascade of  transitions At high excitation: assume continuous level density and statistical emission: At low excitation: through discrete levels Tabulated experimental levels (partial coverage) Rotational approximation outside tabulations See A. Ferrari et al., Z. Phys C 71, 75 (1996) L= multipole order  =level density at excitation energy. U f = strength from single particle estimate (c)+ hindrance (F) 11Paola Sala, Varenna2012June 14th, 2012

12 Ongoing developments for  ’s:  Extended database of known levels and transitions taken from RIPL-3 (IAEA)  Discrete level treatment extended to evaporation stage  Already inserted in the released FLUKA  Photon angular distribution according to multipolarity and spin (  effort to estimate residual spin value and direction in PEANUT, BME, rQMD)  Account for discrete levels in BME (to be extended to rQMD and DPMJET)  Application : prompt photon for in-vivo hadron therapy monitoring 12Paola Sala, Varenna2012June 14th, 2012

13 Prompt photons: benchmarks I 13 Prompt photons measured during irradiation of water and PMMA phantoms with C ions. Photon spectra measured at 90 0 wrt beam Time-of-flight to discriminate neutron background Threshold at 2 MeV to discriminate prompt photons from secondary photons, bremsstrahlung etc. [figures and exp. data taken from F. Le Foulher et al IEEE TNS 57 (2009),E. Testa et al, NIMB 267 (2009) 993] and later revisions

14 Results 14 Blue: fluka Red: data Counts/ion vs position along the phantom (mm) Exp. Energy/tof Distribution and Window 95 MeV/u Bckg subtraction from data to equalize the bckg.level before the target 310 MeV/u Scatter plot and exp. data taken from F. Le Foulher et al IEEE TNS 57 (2009) and later revisions Bragg peak position

15 15 Photon yields by 160 MeV p in PMMA Energy spectrum of “photons” after background subtraction (collimator open – collimator closed) for 160 MeV p on PMMA. FLUKA red line, data black line (J.Smeets et al., ENVISION WP3) Absolute comparison Paola Sala, Varenna2012 Preliminary June 14th, 2012

16 Spin-parity in Fermi-Break-up June 14th, 2012Paola Sala, Varenna For A<16, evaporation is substituted by Fermi break-up In cases where spin and parity of the residual nucleus are known, conservation laws, constraints on available configurations and centrifugal barrier (if L=0 is forbidden), are enforced in the fragment production Straightforward example : photonuclear reaction in the GDR region Effect : residual nuclei production Application: background from induced activity in underground experiments 12C +  in GDR  J  = 1 -  3  and  + 8 Be impossible in L=0  Factor 3 on 11 C production

17 Examples at LHC June 14th, 2012Paola Sala, Varenna201217

18 Application at TeV ( MeV eq. in lab) June 14th, 2012Paola Sala, Varenna BLM response along triplet right of IR5 BLM dose per collision assuming CMS luminosity measurement and 73.5 mb proton-proton cross-section (from TOTEM) Discrepancy possibly due to geometry model (e.g. interconnections are not modeled in detail)

19 Paola Sala, HSS06619 Electromagnetic dissociation: s EM increasingly large with (target) Z’s and energy. Already relevant for few GeV/n ions on heavy targets (s EM ~ 1 b vs s nucl ~ 5 b for 1 GeV/n Fe on Pb) ElectroMagnetic dissociation at LHC ReactionFLUKAALICE (arXiv: v1 [nucl-ex].) Single EMD + nuclear ± 0.3 stat +14.1/–12.1 syst nuclear ± 0.1 stat +0.6/–0.5 syst Single EMD ± 0.2 stat +13.8/–12.0 syst Total electromagnetic and nuclear cross sections (barn) for Pb-Pb interactions at the energy  s NN = 2.76 TeV

20 20June 14th, 2012Paola Sala, Varenna2012


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