3.8. G4Sipm sensitive detector filter¶
The G4SipmSensitiveDetectorFilter
implements the virtual method:
G4bool Accept(const G4Step*)
of its base class G4VSDFilter
which returns true if the photon should be scored by the G4SipmSensitiveDetector
while considering the effects of dead space and the photon detection efficiency.
3.8.1. Dead space¶
The photon should not hit the dead space on the Sipm.
This is checked by the G4SensitiveDetectorFilter::acceptGeometry()
function.
In G4Sipm, the cells of a Sipm are modeled as squares surrounded by a dead space border.
The dead space check can be enabled/disabled by a macro command:
/g4sipm/filter/geometry 1
3.8.2. Photon detection efficiency¶
This is handled by the G4SensitiveDetectorFilter::acceptPde()
function.
The photon detection efficiency (PDE) is a function of the photon wavelength.
A random number between zero and one is picked from a uniform distribution.
If the random number is smaller than the PDE for the photon wavelength, the method returns true.
To account for the reflectivity of the entrance window of the SiPM, the PDE is divided by its transmittance. The transmittance is calculated from a Fresnel-equation for three-layer transmittance whereas for inclined light the transmittance is calculated for unpolarized light. For perpendicular incidence, the transmittance is calculated for parallel polarization following Jackson’s convention.
The PDE check can be enabled/disabled by a macro:
/g4sipm/filter/pde 1
3.8.3. Source¶
-
class
G4SipmSensitiveDetectorFilter
¶ The detector filter for the G4SipmSensitiveDetector.
Handles the loss in sensitivity by the fill factor and the photon detection efficiency.
Inherits from G4VSDFilter
Public Functions
-
G4SipmSensitiveDetectorFilter
(const G4Sipm *sipm)¶ Constructor.
- Parameters
sipm
: - the SiPM.
-
~G4SipmSensitiveDetectorFilter
()¶
-
G4bool
Accept
(const G4Step *step) const¶
Protected Functions
-
bool
acceptPde
(double eKin, double theta) const¶ Dices the acceptance according to the PDE.
- Return
- bool - true if the photon should be accepted.
- Parameters
eKin
: - the energy of the photon.theta
: - the angle of incidence of the photon.
-
bool
acceptGeometry
(double x, double y) const¶ Checks if the photon hits dead space between the single cells.
- Return
- bool - true if the photon should be accepted.
- Parameters
x
: - the x position of the photon.y
: - the y position of the photon.
-