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 14th 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, 2012
Paola Sala, Varenna2012

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
DPMJET3
rQMD-2.4
BME
Muon photonuc
Neutrino
Em-dissociation
Photonuclear
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..):
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++
June 14th, 2012
Paola Sala, Varenna2012

6. Pion production close to DPM thr.
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 + -
June 14th, 2012
Paola Sala, Varenna2012

7. Pion production close to DPM thr.
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 - + +
June 14th, 2012
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, 21085At has a mean life of 8.1 h, 5.6 MeV  decay and  decay to 21084Po
(, 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 FLUKA
It works for Aproj,Atarg 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
BME : E. Gadioli group in Milano
June 14th, 2012
Paola Sala, Varenna2012

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, 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= multipole order
=level density at
excitation energy. U
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
Paola Sala, Varenna2012

13. Prompt photons: benchmarks I
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

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

15. Photon yields by 160 MeV p in PMMA
Absolute comparison
Preliminary
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)
June 14th, 2012
Paola Sala, Varenna2012

16. Spin-parity in Fermi-Break-up
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  + 8Be impossible in L=0
Factor 3 on 11C production
June 14th, 2012
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)
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)
June 14th, 2012
Paola Sala, Varenna2012

19. ElectroMagnetic dissociation at LHC
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)
Total electromagnetic and nuclear cross sections (barn) for Pb-Pb interactions at
the energy sNN = 2.76 TeV
Reaction
FLUKA
ALICE (arXiv: v1 [nucl-ex].)
Single EMD + nuclear
199
194.6 ± 0.3 stat +14.1/–12.1 syst
nuclear
7.67
7.5 ± 0.1 stat +0.6/–0.5 syst
Single EMD
191.3
187.2 ± 0.2 stat +13.8/–12.0 syst
Paola Sala, HSS066

20. Thanks for your attention!
Work partially supported by the ENVISION and PARTNERS European programs
June 14th, 2012
Paola Sala, Varenna2012