Maria Grazia Pia, INFN Genova 1
Low Energy Electromagnetic Physics Low Energy Electromagnetic Physics PART IIPART II
Low Energy Electromagnetic Physics Low Energy Electromagnetic Physics PART IIPART II
Maria Grazia PiaINFN Genova
[email protected] behalf of the Low Energy Electromagnetic Working Group
Geant4 WorkshopHelsinki, 30-31 October 2003
http://www.ge.infn.it/geant4/training/
Maria Grazia Pia, INFN Genova 2
Technology transfer
Particle physics software aids space
and medicine
Geant4 is a showcase example of technology
transfer from particlephysics to other fields such as
space and medical science […].
CERN Courier, June 2002
Maria Grazia Pia, INFN Genova 3
CT-simulation with a Rando phantomExperimental data with TLD LiF dosimeter
CT images used to define the geometry:
a thorax slice from a Rando
anthropomorphic phantom
Comparison with commercial Comparison with commercial treatment planning systemstreatment planning systems
Comparison with commercial Comparison with commercial treatment planning systemstreatment planning systems
M. C. LopesIPOFG-CROC Coimbra Oncological Regional Center
L. Peralta, P. Rodrigues, A. TrindadeLIP - Lisbon
Central-Axis depth dose
Profile curves at 9.8 cm depth
PLATO overestimates the dose at ~ 5% level
Maria Grazia Pia, INFN Genova 4
Brachytherapy
Flexibility of modeling geometries and materials
Radioactive Decay Module
Low energy electromagnetic processes
Interactive facilities: visualisation, analysis, UI
Courtesy of R. Taschereau, UCSF
Maria Grazia Pia, INFN Genova 5
DosimetryDosimetryDosimetryDosimetry
AIDA + Anaphe Python
Analysis of the energy deposit in the phantom resulting from the simulation
Dose distribution
Isodose curves
for analysis for interactivity
may be any other AIDA-compliant analysis system
Simulation of energy deposit through Geant4 Low Energy Electromagnetic package
to obtain accurate dose distributionProduction threshold: 100 m
2-D histogram with energy deposit
in the plane containing the source
Maria Grazia Pia, INFN Genova 6
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Simulazioni Plato Misure
Dos
e %
Distanza lungo X (mm)Distance along X (mm)
SimulationPlatoData
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Dos
e %
Distanza lungo Z (mm)Distance along Z (mm)
SimulationPlato
LongitudinalLongitudinal axis of the source axis of the sourceDifficult to make direct measurementsrely on simulationrely on simulation for better accuracy than for better accuracy than conventional treatment planning softwareconventional treatment planning software
Effects of source anisotropy
TransverseTransverse axis of the axis of the sourcesourceComparison with experimental data validation of the softwarevalidation of the software
S. Agostinelli, F. Foppiano, S. Garelli, M. TropeanoEndocavitary brachytherapy
Role of the simulation: Role of the simulation: precise evaluation precise evaluation of the effects of of the effects of source anisotropysource anisotropy
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Maria Grazia Pia, INFN Genova 7
0 10 20 30 40 500,0
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1,2 Simulazione Nucletron Misure
Dose %
Distanza lungo Z (mm)Distance along Z (mm)
SimulationNucletronData
Experimental validation:Geant4
Nucletron dataIST data
Leipzig applicators
F. Foppiano, M. Tropeano
Superficial Superficial BrachytherapyBrachytherapy
Code reuse:
still the same application as in the previous case
only difference: the implementation of the geometry of the applicator, derived from the same abstract class
No commercial software exists for superficial brachytherapy treatment planning!
Maria Grazia Pia, INFN Genova 8
Leipzig applicator
MicroSelectron-HDR source
DosimetryEndocavitary brachytherapy
DosimetryEndocavitary brachytherapy
DosimetrySuperficial brachytherapy
DosimetrySuperficial brachytherapy
Maria Grazia Pia, INFN Genova 9
Dosimetry Interstitial brachytherapy
Dosimetry Interstitial brachytherapy
Bebig Isoseed I-125 source
0.16 mGy =100%
Isodose curvesIsodose curves
Maria Grazia Pia, INFN Genova 10
RBE enhancement of a RBE enhancement of a 125125I brachytherapy seed with I brachytherapy seed with characteristic X-rays from its constitutive materialscharacteristic X-rays from its constitutive materialsRBE enhancement of a RBE enhancement of a 125125I brachytherapy seed with I brachytherapy seed with characteristic X-rays from its constitutive materialscharacteristic X-rays from its constitutive materials
Per
cent
age
R. Taschereau, R. Roy, J. PouliotCentre Hospitalier Universitaire de Québec, Dépt. de radio-oncologie, Canada
Univ. Laval, Dépt. de Physique, CanadaUniv. of California, San Francisco, Dept. of Radiation oncology, USA
Goal: improve the biological effectiveness of titanium encapsulated 125I sources in permanent prostate implants by exploiting X-ray fluorescence
Titanium shell (50 µm)
Silver core (250 µm)
4.5 mm
All the seed configurations modeled and simulated with
Distance away from seed
RB
E
0 1 2 3 4 5
1
1.02
1.04
1.06
1.08
M200
0 1 2 3 4 5
1
1.02
1.04
1.06
1.08
Mo- Y
M200
-- healthy tissues++ tumors
Maria Grazia Pia, INFN Genova 11
Hadron Therapy Medical Applications
G.A. Pablo Cirrone
On behalf of the CATANA – GEANT4 Collaboration
Qualified Medical Physicist and PhD Student
University of Catania and Laboratori Nazionali del Sud - INFN, Italy
Maria Grazia Pia, INFN Genova 12
Scattering system
Modulator & Range shifter
Monitor chambers
Ligth field
Laser
CATANA hadrontherapy facility
Maria Grazia Pia, INFN Genova 13
Real hadron-therapy beam line
GEANT4 simulation
Maria Grazia Pia, INFN Genova 14
Hadrontherapy: comparison of physics models to data
Standard Processes
Standard + hadronic
Low Energy
Low Energy + hadronic
Maria Grazia Pia, INFN Genova 15
LowE e.m. + hadronic
(precompound)
Difference below 3% even on the peak
Beam Line Validation
Maria Grazia Pia, INFN Genova 16
Difference in penumbra = 0.5 %
Difference in FWHM = 0.5 %
Difference Max in the homogeneity region = 2 %
Lateral Dose Validation
Maria Grazia Pia, INFN Genova 17
Simulation of cellular irradiation with Simulation of cellular irradiation with the CENBG microbeam line using the CENBG microbeam line using GEANT4GEANT4
Sébastien IncertiSébastien Incerti representing the efforts of the representing the efforts of the Interface Physics - Biology group Interface Physics - Biology group
Centre d'Etudes Nucléaires de Bordeaux - GradignanCentre d'Etudes Nucléaires de Bordeaux - Gradignan IN2P3/CNRS IN2P3/CNRS Université Bordeaux 1 Université Bordeaux 1 33175 Gradignan 33175 Gradignan France France
Email : [email protected] : [email protected]
Nuclear Science SymposiumNuclear Science SymposiumPortland, OR, USAPortland, OR, USAOctober 19-25October 19-25thth, 2003, 2003
Maria Grazia Pia, INFN Genova 18
Need for a reliable simulation tool
WHY A SIMULATION TOOL ?
Technical challenge : to deliver the beam ion by ion, in air, keeping a spatial resolution compatible with irradiation at the cell level, i.e. below 10 µm
A simulation tool will help to :
• understand and reduce scattering along the beam line as much as possible : collimator, diaphragm, residual beam pipe pressure…
• understand and reduce scattering inside the irradiation chamber : single ion detector, beam extraction into air, cell culture layer…
• predict ion transport (ray tracing) in the beam line magnetic elements
• dosimetry
with high flexibility and integration. GEANT4GEANT4
Maria Grazia Pia, INFN Genova 19
Testing GEANT4 at the micrometer scale
• horizontal error bars : 5% experimental uncertainty on the foil thickness value• vertical error bars combine statistical fluctuations obtained by varying the number of incident
particles in the simulation and systematic fluctuations of the FWMH values due to the 5 % error on the foil thickness ; they range from 1% to 4% for protons and from 5% to 7% for alphas.
• ICRU_R49p and ICRU_R49He electronic stopping power tables used (G4hLowEnergyIonisation)• Important issue on cuts :
- Default cutValue in PhysicsList.cc : 100 µm and above - Max step length in target foil logic volume (UserLimits) in DetectorConstruction.cc : foil
thickness / 10- low energy EM and standard packages give same results in the measured region of thickness
PROTONSPROTONS
ALPHASALPHAS
Reference
Simulation of ion propagation in the CENBG microbeam line using GEANT4, S. Incerti et al., Nucl. Instr. And Meth. B 210 (2003) 92-97
Maria Grazia Pia, INFN Genova 20
Probability to reach a given 10 µm circular surface :• In vacuum :• Taking into account the residual air ( 5.10-6 mbar ) :
2.37 0.01 MeVT
T s± = ±
70.5( 0.8)%aa pp s± = ±
Beam on target cells
VACUUMVACUUMAIRAIRAIRAIR
99.41( 0.05)%aa pp s± = ±
3.00 MeV 0.06 keVT
T s± = ± In red :scattered bydiaphragm
In blue : no scattering
• Beam initial energy distribution :
• Beam energy distribution on target :
10 µm1 mm
exp 80 90%p » -
Maria Grazia Pia, INFN Genova 21
GATE, a Geant4 based simulation GATE, a Geant4 based simulation platform, designed for PET and SPECTplatform, designed for PET and SPECTGATE, a Geant4 based simulation GATE, a Geant4 based simulation platform, designed for PET and SPECTplatform, designed for PET and SPECT
Steven Staelens
For the OpenGATE collaboration:
Maria Grazia Pia, INFN Genova 22
Overview
Geometry: scanners +sourcesGeometry: scanners +sourcesGeometry: scanners +sourcesGeometry: scanners +sourcesInterface with the user : scripting (macros)
Maria Grazia Pia, INFN Genova 23Courtesy ESA Space Environment & Effects Analysis Section
X-Ray Surveys of X-Ray Surveys of Planets, Planets, Asteroids and MoonsAsteroids and Moons
Induced X-ray line emission:indicator of target composition
(~100 m surface layer)
Cosmic rays,jovian electrons
Solar X-rays, e, p
Courtesy SOHO EIT
Geant3.21
ITS3.0, EGS4
Geant4
C, N, O line emissions included
low energy elow energy e// extensionsextensionswere triggered by astrophysics requirements
Maria Grazia Pia, INFN Genova 24
Fluorescent spectrum of Icelandic Basalt (“Mars-like”)
Experimental data: 6.5 keV photon beam, BESSYCourtesy of A. Owens et al., ESA
ESA Bepi Colombo Bepi Colombo mission to Mercury
Analysis of the elemental composition of Mercury crust through X-ray spectroscopy
X-ray fluorescence, PIXEX-ray fluorescence, PIXE
many more new features,no time to mention them all...
Maria Grazia Pia, INFN Genova 25
LowE at very high energy...LowE at very high energy...LowE at very high energy...LowE at very high energy...
Courtesy of Auger
Fluorescence is an important effect in the simulation of ultra-high energy cosmic ray experiments
Maria Grazia Pia, INFN Genova 26
Geant4 simulationGeant4 simulationof test-mass charging in the LISA missionof test-mass charging in the LISA mission
Very long base-line: 1 million km
Very high precision: < 1nm – 1pm (!)
Maria Grazia Pia, INFN Genova 27
Physics ListPhysics ListPhysics ListPhysics List
EM processes (LowE)Electrons, Gammas, etcAtomic de-excitationHadrons (no hFluorescence)
SecondariesCuts: (250 eV), 1mm - 5mmKill e- outside caging
Maria Grazia Pia, INFN Genova 28
Courtesy of Borexino
lowE physics fluorescence radioactivity neutrons etc..
unique simulation capabilities:
Underground astroparticle experimentsUnderground astroparticle experimentsGran Sasso Laboratory, Italy
Credit: O. Cremonesi, INFN Milano
Maria Grazia Pia, INFN Genova 29
Boulby Mine dark matter Boulby Mine dark matter search Prototype Simulationsearch Prototype Simulation
LXe
GXe
PMT
mirror
source
One High Energy event
Courtesy H. Araujo and A. Howard, IC London
ZEPLIN III
Maria Grazia Pia, INFN Genova 30
...and much more...and much more...and much more...and much more
No time to show all applications
Very good relationship between Geant4 LowE Group and its user community– valuable feedback on applications
– new user requirements to extend and improve the package
Feel free to contact us!
Many user applications become (simplified) advanced examples distributed with Geant4– to help other groups in the user community to get started