Field.txtΒΆ

# Field.txt contains specific source and geometry parameters.
# The parameters settings in this file override parameter settings in the files in the
# includeFile statement below and in LinacDefaults.txt.
#
# Use this parameter control file to set field and patient specific parameters. 
# See Main.txt for additional documentation.
# 
# Reference for geometry: Jabbari et al, J Med Signal Sens 3(3):172-179
# References for electron source incident on x-ray target: 
#   Sawkey and Faddegon, Med Phys 36(3):698-707 (2009)
#   Sawkey and Faddegon, Med Phys 36(12):5622-32 (2009)
# The beam angular divergence from the 36(3) reference is for the manufacture specified 
# water cooling channel thickness.

########################## Key Parameters In Field.txt ###############################
# Parameters marked with "^" are set to be changeable in the TOPAS GUI
# Geometry parameters for one field, including...
# SAD: Source axis distance (distance from nominal source position to isocenter)
# ^IEC_G/RotY_G: IEC gantry rotation angle
# ^IEC_B/RotZ_B: IEC secondary collimator (jaw and MLC) rotation angle
# JawTravelAxis: Direction of jaw travel, along IEC_B axis Xb or Yb
# LeafTravelAxis: Direction of leaf travel, along IEC_B axis Xb or Yb
# ^NegativeFieldSetting: Jaw or MLC leaf position on negative side, projected to isocenter
# ^PositiveFieldSetting: Jaw or MLC leaf position on positive side, projected to isocenter
# LeafWidths: Width of each leaf as projected to isocenter, same width on opposing bank
#
# Source parameters, including...
# BeamEnergySpread: Standard deviation of energy spread in percent 
# NumberOfHistoriesInRun: Total number of source particles to run for simulation
# ShowHistoryCountAtInterval: Number of histories between report of histories run
# Bremsstrahlung splitting used for variance reduction - see user manual
######################################################################################

includeFile = Jaws.txt MLC.txt WaterPhantom.txt  

# Graphics
# Use Gr/Enable to show geometry for a few histories, otherwise set "False" 
#b:Gr/Enable                                  = "True"
b:Gr/Enable                                   = "False"
# Use Ts/UseQT to start TOPAS GUI for a few histories, otherwise set "False" 
#b:Ts/UseQT                                   = "True"
b:Ts/UseQT                                    = "False"

# Random number seed for simulation of this field
i:Ts/Seed                                     = 10

# SAD: Source axis distance (nominal distance from x-ray target to gantry rotation axis)
d:Ge/SAD				      = 100. cm

# Source just upstream of beam limiting devices (jaws, MLC)
s:So/MySource/Type                            = "PhaseSpace"
s:So/MySource/Component                       = "IEC_G"
s:So/MySource/PhaseSPaceFileName              = "PhaseSpaceFixed"
b:So/MySource/PhaseSpaceIncludeEmptyHistories = "True"

i:Ts/ShowHistoryCountAtInterval               = 100000

# Linac geometry field-dependent components
# IEC gantry rotation angle (in the opposite sense of RotY)
dc:Ge/IEC_G/RotY_G                           = 0. deg
d:Ge/IEC_G/RotY                              = -1 * Ge/IEC_G/RotY_G deg

# IEC collimator rotation angle (in the same sense of RotZ)
dc:Ge/IEC_B/RotZ_B                           = 0. deg
d:Ge/IEC_B/RotZ                              = 1 * Ge/IEC_B/RotZ_B deg 

# Asymmetric jaw field settings along IEC coordinates Xb or Yb, projected to isocenter
s:Ge/Jaw/JawTravelAxis                        = "Y" # Jaw travel axis, "X" or "Y"
dc:Ge/Jaw/NegativeFieldSetting                = -20. cm
dc:Ge/Jaw/PositiveFieldSetting                = 20. cm

# MLC leaf widths and positions, projected to isocenter
s:Ge/MLC/LeafTravelAxis                       = "X" # MLC leaf travel "X" or "Y"
dv:Ge/MLC/LeafWidths = 42 5. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 5. cm
# 10 cm x 20 cm field, the field setting for each leaf is that as projected at isocenter
dv:Ge/MLC/NegativeFieldSetting = 42 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. -5. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. cm
dv:Ge/MLC/PositiveFieldSetting = 42 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. cm

# Patient and couch field-dependent components
# IEC couch rotation angle (in the opposite sense of RotZ)
dc:Ge/IEC_S/RotZ_S                           = 0.0 deg
d:Ge/IEC_S/RotZ                              = -1 * Ge/IEC_S/RotZ_S deg