[Gate-users] TPS Pencil Beam Source setting

[jbaran]

Dear Hui Zhang,

I am not sure which version of GATE you are using but from my experience 
it seems that when you are using Pencil Beam source you are able to set 
if your beam is divergent or convergent and you are using convergent 
beam from what I see in your souce code. In case of TPS source the beam 
is divergent by default 
(https://github.com/OpenGATE/Gate/blob/develop/source/physics/src/GateSourceTPSPencilBeam.cc 
- lines: 60 and 61), for sure in GATE 8.2 and 9.0 and I pressume for all 
of GATE versions is the case but you have to check it with your version. 
In my case I just change the default values on true (lines: 60 and 61) 
and recompile GATE once again. Please let us know if it works in your 
case.

All the best,
Jakub



> On 2020-05-19 10:19, 张晖 wrote:
>> Dear Gate Users:
>> 
>>  I previously used Pencil Beam Source to simulate single-energy pencil
>> beam for carbon-ion therapy. The features of the pencil beam source
>> such as spot size, divergence and beam emittance were defined as
>> follows: 3 mm spot size in both x and y directions, 4 mrad divergence
>> and 15 mm·mrad beam emittance. The energy spread was set to 0.1% of
>> the respective energy. Except for dipole scanning magnets,vacuum pipe
>> and window, main and sub-dose monitors, a multi-strip ionization
>> chamber (IC) and a mini ridge filter were modeled in my MC
>> simulations. The source position was located before the vacuum window
>> and a water box was located at isocenter.
>> 
>>  #################Pencil Beam
>> Source########################################
>> 
>>  # SOURCE PBS
>> /gate/source/addSource C12 PencilBeam
>> 
>> #particle type
>> /gate/source/C12/setParticleType GenericIon
>> /gate/source/C12/setIonProperties 6 12 6 0
>> 
>> #energy spectrum
>> /gate/source/C12/setEnergy 2687.52 MeV
>> /gate/source/C12/setSigmaEnergy 2.68752 MeV
>> 
>> #position
>> /gate/source/C12/setPosition 0 0 -1.4059 m
>> 
>> # spot size
>> /gate/source/C12/setSigmaX 3 mm
>> /gate/source/C12/setSigmaY 3 mm
>> 
>> #divergence
>> /gate/source/C12/setSigmaTheta 4 mrad
>> /gate/source/C12/setSigmaPhi 4 mrad
>> 
>> #emittance
>> /gate/source/C12/setEllipseXThetaEmittance 15 mm*mrad
>> /gate/source/C12/setEllipseYPhiEmittance 15 mm*mrad
>> 
>> #positive-> converging beam; negative diverging beam
>> /gate/source/C12/setEllipseXThetaRotationNorm positive
>> /gate/source/C12/setEllipseYPhiRotationNorm positive
>> 
>>  Now, I want to use TPS Pencil Beam Source to simulate realistic
>> treatment plan for carbon ion therapy. In Source-properties.txt file,
>> it contains 8 polynomial equations, each equation being a function of
>> the energy at the nozzle entrance.
>> 
>>  #################TPS Pencil Beam
>> Source-Source-properties########################################
>> 
>>  # Source properties
>> 
>> # Nozzle exit to Isocenter distance
>> 1405.9
>> # SMX to Isocenter distance
>> 4000
>> # SMY to Isocenter distance
>> 4000
>> 
>> # ENERGY
>> # mean energy
>> # polynomial order
>> 1
>> # polynomial parameters (highest to lowest)
>> 1
>> 0
>> 
>> # energy spread
>> # polynomial order
>> percent
>> 1
>> # polynomial parameters (highest to lowest)
>> 0.001
>> 0
>> 
>> # SPOT x y theta phi
>> # x
>> # polynomial order
>> 1
>> # polynomial parameters
>> 0
>> 3
>> # Theta
>> # polynomial order
>> 1
>> # polynomial parameters
>> 0
>> 0.004
>> # y
>> # polynomial order
>> 1
>> # polynomial parameters
>> 0
>> 3
>> # Phi
>> # polynomial order
>> 1
>> # polynomial parameters
>> 0
>> 0.004
>> 
>> # SPOT emmittances
>> # x-theta emmittance
>> # polynomial order
>> 1
>> # polynomial parameters
>> 0
>> 0.015
>> # y-phi emmittance
>> # polynomial order
>> 1
>> # polynomial parameters
>> 0
>> 0.015
>> 
>>  #################TPS Pencil Beam
>> Source-PlanDescriptionToGate########################################
>> 
>>  #TREATMENT-PLAN-DESCRIPTION
>> #PlanName
>> IMPT
>> #NumberOfFractions            ***    CURRENTLY THIS VALUE IS NOT USED
>>   ***
>> 1
>> ##FractionID                ***    CURRENTLY THIS VALUE IS NOT USED
>> ***
>> 1
>> ##NumberOfFields
>> 1
>> ###FieldsID
>> 1
>> 
>> #TotalMetersetWeightOfAllFields        ***    CURRENTLY THIS VALUE IS
>> NOT USED    ***
>> 662421
>> 
>> #FIELD-DESCRIPTION
>> ###FieldID
>> 1
>> ###FinalCumulativeMeterSetWeight    ***    CURRENTLY THIS VALUE IS NOT
>> USED    ***
>> 336732
>> ###GantryAngle (in degrees)
>> 0
>> ###PatientSupportAngle            ***    CURRENTLY THIS VALUE IS NOT
>> USED    ***
>> 0
>> ###IsocenterPosition            ***    CURRENTLY THIS VALUE IS NOT
>> USED    ***
>> 0 0 0
>> ###NumberOfControlPoints
>> 1
>> 
>> #SPOTS-DESCRIPTION
>> ####ControlPointIndex
>> 0
>> ####SpotTunnedID            ***    CURRENTLY THIS VALUE IS NOT USED
>> ***
>> 0
>> ####CumulativeMetersetWeight        ***    CURRENTLY THIS VALUE IS NOT
>> USED    ***
>> 0
>> ####Energy (MeV)
>> 2687.52
>> ####NbOfScannedSpots
>> 1
>> ####X Y Weight (spot position at isocenter in mm, with weight in MU
>> (default) or number of ions "setSpotIntensityAsNbIons true")
>> 0 0 100
>> 
>>  I simulated the same energy beam in my PlanDescriptionToGate.txt file
>> and the spot position is at isocenter. However, I find that the dose
>> distributions with these two sources in water box were different. I'm
>> puzzled about the parameter settings in TPS Pencil Beam Source if I
>> want to make them consistent with those in Pencil Beam Source
>> settings. How can I do?
>> 
>>  Best regards,
>> 
>>  Hui Zhang
>> 
>> -------------------------
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