Test:

1

2/10/2002 Geant4 Workshop CERN

• Test
• Range of e- in different materials

Susanna Guatelli Univ. and INFN Genova CERN
Technical Student
2
CSDA Range
CSDA Range

• (dE/dx)tot is the Stopping Power
• (ionization and Bremsstrahlung)

• T0 is the kinetic energy of e-

• Multiple scattering is not encountered

3
User Requirements

• Model of a simple geometry
• Physical processes for e- in the medium
• Primary particles
• Track of the particles
• Visualization of the geometry involved and of the
  
• trajectories of electrons
• Interactivity the user shall be able to change
  the medium
• Store of the results

4
Design of the test
5

• Electrons are delivered from the center of a box
  with random direction
• The box is filled with absorber material
• The range is calculated as distance between the
  origin and the point
• where the kinetic energy of e- is zero
• Max step set
• Cut in range 1m
• No energy loss fluctuations
• No multiple scattering
• 1Dhistogram in which the range is stored

The range is fixed
Set of the simulation
6

• Test with Low Energy package
• emlowen-V04-01-02
• Test with Standard package
• Geant4-V04-00-00

same experimental set
Ionization Bremsstrahlung
Implemented
Comparison with Report ICRU 37 data
CSDA range No energy loss fluctuations
Protocol adopted in medical physics,
used in the clinical practice
7
Results

Test on elements Beryllium Aluminum Gold Lead Ura
nium
Test on Water Soft tissue Bone Muscle (medical
interest)
Beryllium
range
Beryllium
Comparison The narrow line is the
uncertainty of the ranges reported by ICRU37
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gold
lead
aluminum
uranium

• Low Energy and Standard simulate e-
• range with an acceptable accuracy
• For T010keV the difference is higher
• with Low Energy package
• Improvements !

9
Soft tissue
muscle
Compact bone

• T0lt5 MeV the difference is below or
• equal to 3.
• For T0gt 5 MeV the results can get less accurate
  for both the packages.