Gabriele Cosmo
136 lines
5.1 KiB
Plaintext
136 lines
5.1 KiB
Plaintext
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=========================================================
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Geant4 - Nanobeam example
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=========================================================
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README file
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----------------------
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CORRESPONDING AUTHOR
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S. Incerti (a, *) et al.
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a. Centre d'Etudes Nucleaires de Bordeaux-Gradignan
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(CENBG), IN2P3 / CNRS / Bordeaux 1 University, 33175 Gradignan, France
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* e-mail:incerti@cenbg.in2p3.fr
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---->1. INTRODUCTION.
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The nanobeam example simulates the beam optics of the nanobeam line installed
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on the AIFIRA electrostatic accelerator facility located at CENBG,
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Bordeaux-Gradignan, France. For more information on this facility,
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please visit :
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http://www.cenbg.in2p3.fr/
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The code can be used to calculate :
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1) intrinsic aberration coefficients of the nanobeam line
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2) beam image from a relasitic primary emittance distribution
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3) grid shadow images
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Three quadrupole field models can be used :
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- a simple square field model
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- a 3D mesh field model computed from OPERA3D
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- an analytical model based on Enge's model
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---->2. GEOMETRY SET-UP.
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The full magnetic configuration of the nanobeam line is simulated.
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This configuration is made of a combination of a doublet and triplet of
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5 Oxford Microbeams Ltd. OM50 quadrupoles.
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More details on the experimental setup and its simulation with Geant4 can
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be found in the following papers:
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- A DETAILED RAY-TRACING SIMULATION OF THE HIGH RESOLUTION MICROBEAM AT THE
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AIFIRA FACILITY
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By F. Andersson, Ph. Barberet, S. Incerti, Ph. Moretto
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Published in Nucl.Instrum.Meth.B266:1653-1658, 2008
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- MONTE CARLO SIMULATION OF THE CENBG MICROBEAM AND NANOBEAM LINES WITH THE
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GEANT4 TOOLKIT
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By S. Incerti, Q. Zhang, F. Andersson, Ph. Moretto, G.W. Grime,
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M.J. Merchant, D.T. Nguyen, C. Habchi, T. Pouthier and H. Seznec
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Published in Nucl.Instrum.Meth.B260:20-27, 2007
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- GEANT4 SIMULATION OF THE NEW CENBG MICRO AND NANO PROBES FACILITY
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By S. Incerti, C. Habchi, Ph. Moretto, J. Olivier and H. Seznec
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Published in Nucl.Instrum.Meth.B249:738-742, 2006
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- A COMPARISON OF RAY-TRACING SOFTWARE FOR THE DESIGN OF QUADRUPOLE MICROBEAM
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SYSTEMS
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By S. Incerti et al.,
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Published in Nucl.Instrum.Meth.B231:76-85, 2005
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---->3 VISUALIZATION
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Visualization has not been implemented.
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---->4. HOW TO RUN THE EXAMPLE
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1) You must have compiled your Geant4 installation with the FULL version of the
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CLHEP library which can handle matrix operations.
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2) The code should be compiled cmake and run with :
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./nanobeam
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The macro file default.mac is read by default.
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Several macro files are provided:
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1) for the computation of intrinsic aberration coefficients :
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coef-square.mac : using square magnetic field model
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coef-map.mac : using 3D map magnetic field model
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coef-enge.mac : using Enge's analytical field model
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2) for the simulation of the beam image with a realistic emittance :
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image-square.mac : using square magnetic field model (=default.mac)
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image-map.mac : using 3D map magnetic field model
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image-enge.mac : using Enge's analytical field model
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3) for the simulation of grid shadow images
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grid-square.mac : using square magnetic field model
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grid-map.mac : using 3D map magnetic field model
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grid-enge.mac : using Enge's analytical field model
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These macros files are stored in the ./macros directory.
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To run macros which include *map* in their name, copy the file OM50.grid
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into the directory in which you run ./nanobeam.
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The code can be run in MT mode, for high statistics image simulation.
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Do not use MT for aberration coefficients calculation (32 rays only are shot).
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The switch to MT can be made in nanobeam.cc.
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---->5. PHYSICS
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The example runs with protons with fluctuating energies around 3 MeV.
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Standard electromagnetic processes are activated by default (corresponding to the
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Physics builder G4EmStandardPhysics), including the G4StepLimiter process.
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---->6. SIMULATION OUTPUT AND RESULT ANALYZIS
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All results are stored in the nanobeam.root file and can be displayed with the provided
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ROOT macro file plot.C:
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* be sure to have ROOT installed on your machine
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* be sure to be in the directory where ROOT output files are generated
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* copy plot.C into this directory
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* launch ROOT by typing root, then under your ROOT session, type in : .X plot.C
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to execute the macro file
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* or type directly: root plot.X
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This macro file shows :
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- the beam profile along the nanobeam line (only for the computation of intrinsic
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coefficients)
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- the beam image (Y vs X) on target
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- the beam emittance (THETA vs X) and (PHY vs Y) on target
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- the grid shadow image (option)
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The output ntuples can be written as xml or csv files, by changing the G4AnalysisManager default file type in RunAction::BeginOfRunAction().
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---------------------------------------------------------------------------
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Should you have any enquiry, please do not hesitate to contact:
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incerti@cenbg.in2p3.fr
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