518
J. Apostolakis
The prototype calorimeter with analog readout consisted of 38 layers, each
containing a steel absorber plate and a scintillator layer. The 30 × 30 cm 2 core
of the scintillator had granularity 3 × 3 cm 2 , and outer regions 6 × 6 cm 2 and
12 × 12 cm 2 . Data was collected with pions between 8 GeV and 100 GeV and
compared with Monte Carlo simulation [120] using GEANT4 version 9.4.
The fine segmentation allows the estimation of the layer of the first hard
interaction. This is used to obtain the shower profile relative to this starting layer.
Averaging over showers starting in different layers reduces the effect of the variation
of calibration, and is used to estimate uncertainties.
Comparisons of the mean longitudinal and lateral shower profiles for 8 GeV,
18 GeV and 80 GeV pions with GEANT4 physics lists including QGSP_BERT and
FTFP_BERT were provided.
Figure 11.9 top row shows the longitudinal shower profile for pions of 8 GeV
(left), 18 GeV (center) and 80 GeV (right) compared with GEANT4 physics lists
FTFP_BERT.
Normalization to unit total is used in each distribution. For FTFP_BERT less
energy is deposited in the early shower layers at all energies. At 80 GeV a difference
is seen in the shower maximum of 10% (FTF versions) to 20% (QSGP versions),
and the shower is more compact.
Similar comparisons for the radial shower profile show that all physics lists
underestimate the radial extent of the showers and have a larger fraction of energy
in the core. The effect is most pronounced at 80 GeV, see Fig. 11.10.
Either improvement of the relevant models or alternative physics models is
needed to better describe these shower shapes, and provide the accuracy to use the
full potential of simulation for future highly granular calorimeters.
11.6 Applications in Other Fields
Particle transport simulation tools, including GEANT4 and FLUKA, have seen
greatly increasing usage beyond High Energy and Nuclear Physics (HENP) experiments in the past decade.
In particular in medical physics, their application has seen spectacular growth,
and has spanned several domains, especially the development and refinement of
new methods and assessment of treatments in radiotherapy, and the simulation of
medical imaging detectors.
J. Apostolakis
The prototype calorimeter with analog readout consisted of 38 layers, each
containing a steel absorber plate and a scintillator layer. The 30 × 30 cm 2 core
of the scintillator had granularity 3 × 3 cm 2 , and outer regions 6 × 6 cm 2 and
12 × 12 cm 2 . Data was collected with pions between 8 GeV and 100 GeV and
compared with Monte Carlo simulation [120] using GEANT4 version 9.4.
The fine segmentation allows the estimation of the layer of the first hard
interaction. This is used to obtain the shower profile relative to this starting layer.
Averaging over showers starting in different layers reduces the effect of the variation
of calibration, and is used to estimate uncertainties.
Comparisons of the mean longitudinal and lateral shower profiles for 8 GeV,
18 GeV and 80 GeV pions with GEANT4 physics lists including QGSP_BERT and
FTFP_BERT were provided.
Figure 11.9 top row shows the longitudinal shower profile for pions of 8 GeV
(left), 18 GeV (center) and 80 GeV (right) compared with GEANT4 physics lists
FTFP_BERT.
Normalization to unit total is used in each distribution. For FTFP_BERT less
energy is deposited in the early shower layers at all energies. At 80 GeV a difference
is seen in the shower maximum of 10% (FTF versions) to 20% (QSGP versions),
and the shower is more compact.
Similar comparisons for the radial shower profile show that all physics lists
underestimate the radial extent of the showers and have a larger fraction of energy
in the core. The effect is most pronounced at 80 GeV, see Fig. 11.10.
Either improvement of the relevant models or alternative physics models is
needed to better describe these shower shapes, and provide the accuracy to use the
full potential of simulation for future highly granular calorimeters.
11.6 Applications in Other Fields
Particle transport simulation tools, including GEANT4 and FLUKA, have seen
greatly increasing usage beyond High Energy and Nuclear Physics (HENP) experiments in the past decade.
In particular in medical physics, their application has seen spectacular growth,
and has spanned several domains, especially the development and refinement of
new methods and assessment of treatments in radiotherapy, and the simulation of
medical imaging detectors.