Transcript FLUKA towards applications in hadrontherapy - INFN

Atmospheric Muon Simulation using
the FLUKA MC Model
G.Battistoni, A.Ferrari, S.Muraro, T.Montaruli P.R. Sala
INFN & Univ.Milano, CERN, Madison Univ. of Winscosin
Work carried on within the program of the
FLUKA Collaboration
F.Ballarini, G.Battistoni, M.Campanella, M.Carboni, F.Cerutti, A.Empl, A.Fassò, A.Ferrari, E.Gadioli,
M.V.Garzelli, M.Lantz, A.Mairani, A.Mostacci, S.Muraro, A.Ottolenghi, M.Pelliccioni, L.Pinsky,
J.Ranft, S.Roesler, P.R.Sala, D.Scannicchio, S.Trovati, V.Vlachoudis, R.Villari, T.Wilson, N.Zapp
INFN-Mi, LNF, Pv, Univ. Milano, Univ. Pavia, CERN, Univ. of Houston, SLAC, Univ. of Siegen,
NASA-Houston
Outline:
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2)
3)
4)
5)
6)
Motivations
The key features of FLUKA hadronic models at high energy
the FLUKA cosmic ray library
Results 1: up to 100 GeV region
Results 2: beyond the 100 GeV region
The TeV region: prediction about the prompt component at
very high energy and multimuon events
7) Conclusions
FLUKA
Authors: A. Fasso`1, A. Ferrari2, J. Ranft3, P.R. Sala4
1
SLAC Stanford, 2 CERN, 3 Siegen University, 4 INFN Milan
Interaction and Transport Monte Carlo code
FLUKA 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, radioprotection, radiotherapy etc.,
 therefore can be used in cosmic rays
Maintained and developed under INFN-CERN agreement and copyright
1989-2006; More than 1000 users all over the world;
see http://www.fluka.org
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Specific Motivations
FLUKA is designed and maintained searching for high degree of
quality in physics models and algorithms.
Model building based on “microscopic” concepts that allow to be
predictive even where data do not yet exist. We do not rely on
parametrizations. Minimiz. of the number of free parameters. Not
flexible everywhere: cannot be forced at pleasure.
Benchmarked ONLY with data from well controlled situations (typically
thin target exp at accelerators)
The interest in c.r. physics arises from a twofold necessity:
1. Basic research: investigate how a model based upon the above
principles is able to explain/predict c.r. fluxes (e.g. the calculation
of atmospheric neutrinos). Muons are a good subject.
2. FLUKA groups working in fields like radioprotection in space and
in atmosphere need these comparisons to take confidence on the
reliability of their calculations.
The FLUKA hadronic Models
Hadron-Hadron
Elastic,exchange
Phase shifts
data, eikonal
P<3-5GeV/c
Resonance prod
and decay
Hadron-Nucleus
E < 5 GeV
PEANUT
Sophisticated GINC
Preequilibrium
Coalescence
High Energy
Glauber-Gribov
multiple interactions
Coarser GINC
Coalescence
> 5 GeV Elab
low E π,K
Special
High Energy
DPM
hadronization
Nucleus-Nucleus
E< 0.1GeV/u
BME
Complete fusion+
peripheral
0.1< E< 5 GeV/u
rQMD-2.4
modified
new QMD
Evaporation/Fission/Fermi break-up
 deexcitation
E> 5 GeV/u
DPMJET
DPM+
Glauber+
GINC
Relevant for
HE C.R. physics
DPM: soft physics based on (multi)Pomeron exchange
DPMJET: soft physics of DPM plus 2+2 processes from pQCD
Comparison with the HARP experiment
Data from the HARP
experiment at CERN
particle production
with p beams in the
1.5-15 GeV/c range
on several targets
First published
results : 12.9 GeV/c
protons on
Aluminum,
+ production cross
section as a function
of emission
momentum and
angle
The relevant key features
(mostly for inclusive calculations)
Above few tens of GeV:
approximate Feynman scaling
X
E, K ,...
Ep
the “Z-moments” from FLUKA in
p-Air interaction
 1
Z     
1
dnpN  X
0
E

;   2. 7
Ep
+
-
K+
K-
d
d
Muon and Neutrino fluxes:
Semi-analytic calculations
The above distributions can be inserted in the formalism described by
T.K.Gaisser in Astropart.Phys. 16 (2002) 285 (1-dimensional,
exponential atmosphere, exact Feynman scaling, ecc.)
X dn/dX
m flux weight by E3
FLUKA+DPMJET: behaviour @1000 TeV
As expected: violation of scaling in the “central’ region (low rapidity)
naive behaviour
~(1-x)b
The FLUKA C.R. library
Dedicated FLUKA library + additional off-line packages including:
Primary spectra from Z = 1 to Z = 28 (derived from NASA and
updated to most recent measurements.)
Solar Modulation model (correlated to neutron monitors)
Atmospheric model (MSIS Mass-Spectrometer-Incoherent-Scatter)
3D geometry of Earth + atmosphere
FLUKA:
Geomagnetic model
superposition model
nucleon-Air interaction
FLUKA+DPMJET(II or III):
full N-Air interactions
Basic primary fluxes
modulated for a given date,
location according to geomag.
model, solar modulation
other primary choices possible, for instance the Bartol all-nucleon spectrum
Example of geometry setup for
earth + local atmosphere
100 layers
50 or 200
as options
Cone amplitude
Depending on allowed tolerance
On geomagnetic cut-off
For the special case of atmospheric neutrinos
the whole earth is instead considered
The output of the cosmic FLUKA library:
At user request:
Fluences or currents of charged/neutral particles
in atmosphere at different altitudes (@boundary X-ing between layers)
in the form of double differential distributions with respect to
energy or momentum or angles or xF or xLab or etc. etc.
AND/OR: spatial distributions in x-y-z or R-z-f coordinates
AND/OR: event by event output
AND/OR: particle trajectories  shower drawing
The simulation of muon fluxes:
In the recent years many new data sets have been published.
In particular the BESS spectrometer has collected data at different
cut-offs, altitudes, solar modulation
Up to 10-20 GeV: BESS muons @Lynn Lake (1997)
Very Low Cut-off: 0.4 GV
m
+
m
cone of
~25o
Up to 100 GeV: BESS muons @Mnt Norikura (1999)
2,700 m asl
Cut-off: 11.2 GV
m
m+
BESS: high altitude hadron fluxes
exp. data
FLUKA simulation
here:
atmospheric profile from MSIS different from data,
cut-off might be too approximated
BESS: high altitude muon fluxes
Here, unspectedly, simulation exceed REAL DATA
The difference in atmospheric profile could have relevance
for decay prob. of pions
The all-nucleon spectrum of the simulation
towards higher energies: constrained to join KASKADE measurements
Beyond the 100 GeV region: L3 Muons
exp. data
Vertical
at larger angle
FLUKA simulation
Very High Energies:
convntional + prompt muons and neutrinos
Presented at ICRC 2005
Knee model: following KASCADE results
A benchmark on charmed
meson production (OLD)
A look at particle production at 1 PeV
Pions
Kaons
A comparison with results
from the models contained
in CORSIKA
(with R.Ganugapati, A.Karle,
J.L.Kelley, Univ. of Winsconsin)
Charm (Meson+Baryon)
Muons in EAS: 1 TeV vertical p prim.
Integral at sea level: ~ 21 m/p
sea level
2800 m
6200 m
10200 m
Using FLUKA for underground m-bundles
The aim is to predict multiple muon rates for
different primary masses and energy within
the framework of a unique simulation model
Within ICARUS collaboration
Four steps:
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2)
3)
4)
atmospheric shower generation
transport in Gran Sasso rock
folding with the detector (spatial randomization of event)
full simulation in ICARUS T600
Voxel geometry
description of
GranSasso
Interaction model: FLUKA + DPMJET-II for nucleus-nucleus collisions Secondary threshold
= 1 TeV
Output: muons (E > 1 TeV) event by event
Muon Yield underground
3100 hg cm-2
q ~ 30o
Continuos lines are the parametrization
obtained from the MC code used for
MACRO analysis
[C.Forti et al. (1990)]
Fe nuclei
protons
Systematic differences
at the level of 15% exist
between
FLUKA
FLUKA+DPMJET2
FLUKA+DPMJET3
in yield and radial distr.
First results: folding with FLUKA full simulation
in ICARUS
Fe nuclei,
1000 TeV/nucleon
Conclusions
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FLUKA results for muon fluxes in atmosphere are in general satisfactory
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The numerical results are strongly dependent on the choice of primary flux.
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To a lesser extent, other details still seem to be important: atmosphere, algorithm of
solar modulation and geomagnetic cutoff
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FLUKA can be successfully operated also at very high energy (tested in part up to 106
GeV)
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At these energy the coupling FLUKA+DPMJET (2 or 3) is probably more reliable, at
least for theoretical reasons (the hard QCD contribution must not be neglected)
The FLUKA library for c.r. fluxes can be made available to interested people
(documentation is still in progress)
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The primary fluxes of FLUKA library for C.R. physics in the atmosphere should
probably be improved
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dN/dX distributions for semi-analytic calculations can be made available for fast
numerical evaluation