G4beamline Simulation Program for MatterDominated Beamlines - PowerPoint PPT Presentation

Title: G4beamline Simulation Program for MatterDominated Beamlines


1
G4beamline Simulation Program for
Matter-Dominated Beamlines Thomas J. Roberts1,
Shahid Ahmed1,2, Kevin B. Beard1, Dazhang
Huang1,2, Daniel M. Kaplan2 1Muons, Inc.,
2Illinois Institute of Technology
http//g4beamline.muonsinc.com
example2 describes a muon cooling beamline
concept consisting of 4 sets of liquid hydrogen
filled absorbers with aluminum windows,
solenoids, and RF cavities. The images at left
are from the G4beamline Open Inventor display
the ones on the right were taken from a root
ntuple that logged all particles passing through
one of the virtual detectors placed in the
model. G4beamline can read and write a number
of formats and can be used in combination with a
number of other programs.

• Introduction
• Open Source GPL license (free)
• Optimized for the design and evaluation of beam
  lines
• Based on the Geant4 toolkit 1
• Can implement accurate and realistic simulations
• Well suited for studies of muon collider and
  neutrino factory design concepts
• G4beamline includes a rich repertoire of beamline
  elements
• Use it directly, without C programming
• Large class of beamline and detector systems
• Available on Linux, Windows, and Macintosh
  platforms
• Undergoing constant active development
• Has both a line and a graphical interface

RF
m

• Entire G4beamline input file example2.in
• example2.in 4/2/03 TJR Simple example
  g4beamline file There are 4 Study2 cooling
  cells. This version uses a Gaussian beam
  trace the first 10 eventstrace nTrace10
  QGSP is the "default" physics use-case for
  HEPphysics QGSP disableDecaybeam gaussian
  meanMomentum200 sigmaP-10 sigmaXp0.01 \
  sigmaYp0.01 nEvents100 beamZ0
• reference particlemu referenceMomentum200.0
  beamZ0trackcuts kineticEnergyCut50.0
  killSecondaries1 define the solenoids (use
  individual Focus solenoids for
• alternate1 to work)coil default materialCu
  dR5.0 dZ5.0 solenoid default alternate1
  color1,1,0coil Focus1 innerRadius330.0
  outerRadius505.0 length167.0 \
• maxR330.0coil Coupl1 innerRadius770.0
  outerRadius850.0 length330.0 \
  maxR770.0solenoid USFocus coilNameFocus1
  current75.20solenoid DSFocus coilNameFocus1
  current-75.20solenoid Coupl coilNameCoupl1
  current-98.25 define a detector for the
  center of each absorbervirtualdetector Det
  radius179.9 length1 define the absorber with
  flat Al windowstubs Win1 outerRadius180.0
  length0.360 \
• materialAl color0.0,1.0,0.0tubs LH2
  length350.0 outerRadius180.0 color1.0,0.0,1.0
  \
• materialLH2 place the virtualdetector into
  the absorber, so its front is in
• the centerplace Det z0.5 parentLH2
  color1,1,1group Abs radius0 place
  Win1 place LH2 place Win1endgroup tune the
  RF Gradienttune Grad z0100 z111300 initial15
  step0.1 exprPz1-Pz0 \
• tolerance0.001 define the pillbox RF
  cavity, and put 4 of them into a linacpillbox RF
  innerLength466.0 frequency0.20125
  maxGradientGrad \ irisRadius160.0
  win1Thick0.300 \
• win2Thick0.700 \wallThick5.0 \ winMatBe
  collarThick5.0 phaseAcc40.0 maxStep10.0group
  Linac1 radius0 place RF renameRF
  copies4endgroup define one cooling
  cellgroup Cell length2750.0 place Abs
  z-1033.0 place USFocus z-1291.5
  renameFocus place DSFocus z-774.5
  renameFocus place Coupl z342.0
  renameCoupl place Linac1 z342.0
  rename''endgrouptubs Spacer length200
  outerRadius300 materialVacuumplace Spacer
  z100 place 4 cellsplace Cell copies4
  renameCplace Spacer 

solenoids
Al
m
LH2

• A physicist-readable ASCII file specifies the
  simulation
• The complexity of the description is comparable
  to the complexity of the system being simulated
• A rich repertoire of beamline elements
• Can be combined to define new and customized
  elements
• A general set of initial beam specifications
• Including a cosmic-ray muon beam and external
  files
• Beam tracks can be input and output using several
  formats including ASCII and Root 2 files
• Visualization of the system is included, using
  many viewers (OpenGL, VRML, Open Inventor, Wired,
  DAWN, RayTracer, etc.)
• Many parameters can be automatically tuned
• RF cavity timing and gradients, bending magnet
  fields, etc.
• Support for parallel jobs on multiple CPUs
• Includes the historoot program, which makes it
  easy for non-experts to generate Root histograms
  and plots

The MICE Beamline and Cooling Channel 3 The
MICE expriment currently under construction at
RAL will test muon cooling. The pion production
target is at the upper left, inside the ISIS
ring (not shown) Quadrupoles green (HF), blue
(HD) Bending magnets red Solenoids yellow Beam
pipes gray and white 2 RF Cavities
gray Calorimeter light blue

• Summary
• G4beamline has been in use for several years, and
  is rapidly evolving
• Half-dozen research groups
• Several dozen different systems
• The learning curve is short for a program of this
  scope.
• With sufficient attention to detail, the
  simulation can be quite realistic.
• The development of G4beamline is ongoing, and its
  features and facilities are expanding.
• Comments and suggestions from potential and
  actual users are welcome
• http//g4beamline.muonsinc.com

• The G4beamlineGraphical User Interface
• Interactive program control
• Comprehensive Help page
• Windows, Mac OS, and Linux

Acknowledgements Work supported by DoE STTR grant
DE-FG02-6ER86281.
References 1 http//geant4.cern.ch 2
http//root.cern.ch 3 http//mice.iit.edu