Maria Grazia Pia, INFN Genova 1 Low Energy Electromagnetic Physics PART II Maria Grazia Pia INFN...

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/


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


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


Brachytherapy

Flexibility of modeling geometries and materials

Radioactive Decay Module

Low energy electromagnetic processes

Interactive facilities: visualisation, analysis, UI

Courtesy of R. Taschereau, UCSF


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


-40 -30 -20 -10 0 10 20 30 400,0

0,5

1,0

1,5

2,0

2,5

Simulazioni Plato Misure

Dos

e %

Distanza lungo X (mm)Distance along X (mm)

SimulationPlatoData

-40 -30 -20 -10 0 10 20 30 400,0

0,5

1,0

1,5

2,0

2,5 Simulazioni Plato

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

-40 -30 -20 -10 0 10 20 30 40-40

-30

-20

-10

0

10

20

30

40 Cut 0.1mm

200% 150% 100% 75% 50% 25%

Dis

tanza

lungo Z

(m

m)

Distanza lungo X (mm)


0 10 20 30 40 500,0

0,2

0,4

0,6

0,8

1,0

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!


Leipzig applicator

MicroSelectron-HDR source

DosimetryEndocavitary brachytherapy

DosimetryEndocavitary brachytherapy

DosimetrySuperficial brachytherapy

DosimetrySuperficial brachytherapy


Dosimetry Interstitial brachytherapy

Dosimetry Interstitial brachytherapy

Bebig Isoseed I-125 source

0.16 mGy =100%

Isodose curvesIsodose curves


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


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


Scattering system

Modulator & Range shifter

Monitor chambers

Ligth field

Laser

CATANA hadrontherapy facility


Real hadron-therapy beam line

GEANT4 simulation


Hadrontherapy: comparison of physics models to data

Standard Processes

Standard + hadronic

Low Energy

Low Energy + hadronic


LowE e.m. + hadronic

(precompound)

Difference below 3% even on the peak

Beam Line Validation


Difference in penumbra = 0.5 %

Difference in FWHM = 0.5 %

Difference Max in the homogeneity region = 2 %

Lateral Dose Validation


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


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


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


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 » -


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:


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


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...


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


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 (!)


Physics ListPhysics ListPhysics ListPhysics List

EM processes (LowE)Electrons, Gammas, etcAtomic de-excitationHadrons (no hFluorescence)

SecondariesCuts: (250 eV), 1mm - 5mmKill e- outside caging


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


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


...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

Maria Grazia Pia, INFN Genova 1 Low Energy Electromagnetic Physics PART II Maria Grazia Pia INFN...

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