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Hit Structure
Two HIT structures associated to the two implemented models have been defined in Bogus for DCH.
The information stored in the hits are different in the two cases.
- Cylinder: The hit structure contains data referring to the particle crossing the chamber. One hit for each crossing track will be produced.
The following table describes the stored information:
Cylinder Hit structure
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Number
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Class Type
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Name |
Description
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1,2,3
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G4ThreeVector
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enterPosition |
Entrance position in the chamber
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4,5,6
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G4ThreeVector
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enterMomentum
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Momentum at the entrance
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7,8,9
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G4ThreeVector
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exitPosition
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Exit position from the chamber
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10,11,12
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G4ThreeVector
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exitMomentum
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Momentum at the exit point
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13
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G4double
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path
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Path Length
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14
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G4double
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depositEnergy
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Deposited Energy
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11
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G4int
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gtrack
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Track Id
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12
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G4int
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particle
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Particle Type
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| 13,14,15,16,17 |
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particlePid
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Pid Probabilities
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18
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G4double
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gtime
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Geant TOF
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19
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G4int
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flag
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Particle Flag
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- Layer: The hit contains more information related to every single step (every single layer).
As shown in the picture, the intersections of the particle trajectories with the layer edge (containing the sense wires i.e. the orange points) are considered to estimate the parameters associated to the response of the
chamber:
- Layer and Cell number:
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- The size in Phi of the cells in the corresponding layer is used to determine these values.
- Distance of Closest Approach:
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- The distance between the particle trajectory in the intersection point and the sense wire line is a good approximation of this parameter for particles having a not very low momentum.
For low momentum particles a parabolic approximation of the trajectory is required (not yet implemented).
- Deposited Energy:
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- The dE/dx response of the chamber is parameterized using the path in the cell.
The path will be parameterized as a function of the distance from the sense wire, the momentum and direction of the particle.
The hit structure in this case will be:
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Layer Hit structure
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Number
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Class Type
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Name |
Description
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1
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G4int
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layer |
Layer
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2
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G4int
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cell
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Cell
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3,4,5
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G4ThreeVector
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position
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Particle Intersection
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6,7,8
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G4ThreeVector
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momentum
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Momentum
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9
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G4double
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path
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Path Length
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10
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G4double
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depositEnergy
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Deposited Energy
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11
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G4int
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gtrack
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Track Id
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12
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G4int
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particle
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Particle Type
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13
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G4double
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gtime
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Geant TOF
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14
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G4int
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flag
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Particle Flag
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15
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G4double
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radiationLenght
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Material Radiation lenght
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16
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G4double
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closestApproach
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Closest approach distance
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For information: Ernesto Lamanna or Caterina Perri |
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