New developments in FLUKA

Paola SalaINFN Milano

On behalf of the FLUKA collaboration≈ 50 members from several institutions around the world

Varenna, June 14th 2012

http://www.fluka.org

Paola Sala, Varenna2012 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 transportIn 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 applicationsJune 14th, 2012 http://www.fluka.org

Paola Sala, Varenna2012 3

Hadron interactions in FLUKA: an integrated ensemble

h-hDPM + quark chain

hadronization

Resonance production and

decay

Elastic, ch.exc.

h-APEANUT

Glauber-Gribov multiple collisions

G-INC

Preequilibrium (Exciton)

Evaporation/Fragmentation or Fermi Break-up

deexcitation

A-A

DPMJET3

rQMD-2.4

BME

Muon photonuc

Neutrino Em-dissociationPhotonuclear

June 14th, 2012

Paola Sala, Varenna2012 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 pT , including baryons, mesons, resonances.

June 14th, 2012

Paola Sala, Varenna2012 5

Neutrino interactions (ICARUS..):

June 14th, 2012

Fluka has its own neutrino interaction generator, including QE, Resonance, DISDIS uses the same chain hadronization as DPMEmbedded in the FLUKA nuclear environment (PEANUT)New low-mass chain treatment-> improvements in the RES-DIS transition

μ+p ->μ- +p++

Paola Sala, Varenna2012 6

Pion production close to DPM thr.

June 14th, 2012

Pion production from proton interactions on Be at 12.3 GeVEmitted pion spectra at different angles in the range 300 - 600 Dots: data (BNL910 expt.), histograms : Fluka

- +

Paola Sala, Varenna2012 7

Pion production close to DPM thr.

June 14th, 2012

Pion production from proton interactions on Be at 17.5 GeVEmitted pion spectra at different angles in the range 00 - 200 Dots: data (BNL910 expt.), histograms : Fluka

-

+

+

Paola Sala, Varenna2012 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, 210

85At has a mean life of 8.1 h, 5.6 MeV decay and decay to 210

84Po (, 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 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, 2012

Paola Sala, Varenna2012 9

FLUKA: the BME Model for nucleus – nucleus interactions below 150 MeV/n

The BME ( Boltzmann Master Equation) in FLUKAIt works for Aproj,Atarg 4, E 150 MeV/A

1. COMPLETE FUSION 2. PERIPHERAL COLLISIONthree body mechanism

withincomplete fusionone 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, 2012BME : E. Gadioli group in Milano

Paola Sala, Varenna2012 10

BME in FLUKA : (,xn) examplesExcitation functions for the production of radioisotopes from interactions on Au (left) and Pb ( right) (Data: CSISRS, NNDC)

June 14th, 2012

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

ii

ff LEfUU

dEEP ),()()(

)( L= multipole order

=level density at excitation energy. U

)12()(),( LLL EAFcLEf

f = strength from single particle estimate (c)+ hindrance

(F)

June 14th, 2012

Paola Sala, Varenna2012 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 FLUKA2011.2 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

June 14th, 2012

Prompt photons: benchmarks I

13

Prompt photons measured during

irradiation of water and PMMA

phantoms with C ions.

Photon spectra measured at 900

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

Results

14

Blue: flukaRed: data

Counts/ion vs position along the phantom

(mm)

Exp. Energy/tofDistribution 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

Paola Sala, Varenna2012 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

Preliminary

June 14th, 2012

Paola Sala, Varenna2012 16

Spin-parity in Fermi-Break-up

June 14th, 2012

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 productionStraightforward example : photonuclear reaction in the GDR regionEffect : residual nuclei production Application: background from induced activity in underground experiments

12C + in GDRJ = 1-

3 and + 8Be impossible in L=0

Factor 3 on 11C production

Paola Sala, Varenna2012 17

Examples at LHC

June 14th, 2012

Paola Sala, Varenna2012 18

Application at 3.5+3.5 TeV (2.6 1010 MeV eq. in lab)

June 14th, 2012

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)

Paola Sala, HSS066 19

Electromagnetic dissociation: sEM increasingly large with (target) Z’s and energy. Already relevant for few GeV/n ions on heavy targets (sEM ~ 1 b vs snucl ~ 5 b for 1 GeV/n Fe on Pb)

211 )()(

21Znnd

AA

ElectroMagnetic dissociation at LHC

Reaction FLUKA ALICE (arXiv:1203.2436v1 [nucl-ex].)

Single EMD + nuclear 199 194.6 ± 0.3 stat +14.1/–12.1 systnuclear 7.67 7.5 ± 0.1 stat +0.6/–0.5 systSingle EMD 191.3 187.2 ± 0.2 stat +13.8/–12.0 syst

Total electromagnetic and nuclear cross sections (barn) for Pb-Pb

interactions atthe energy sNN = 2.76 TeV

Paola Sala, Varenna2012 20

Thanks for your attention!

Work partially supported by the ENVISION and PARTNERS European programs

June 14th, 2012