GRIFFIN Efficiency Calculator

Simulation Details

• HPGe GEANT4 Simulation: 8th order polynomial fit including SCEPTAR and Delrin vacuum chamber.
• LaBr3 GEANT4 Simulation: 8th order polynomial fit above 40 keV including SCEPTAR and Delrin vacuum chamber.
• Si(Li) Simulation: Relative Efficiency curve shape based on formalism referenced in Radiation Detection & Measurement (G.F. Knoll, Wiley 2000). Note that the Si(Li) simulations are known to differ from experiment at the 30% level. An absolute normalization is applied per Masters Thesis of Ryan Dunlop, University of Guelph, 2012, "High-precision branching ratio measurement for the superallowed β⁺ emitter ⁷⁴Rb", based on the analysis of in-beam ⁸⁰Rb decay.
• SCEPTAR GEANT4 Simulation: triple Fermi function fit adjusted to asymptotically approach 0.8 at high Q per experiment. Low-Q position efficiencies fixed to 0.065% per simulated annihilation photopeak efficiency.
• The following four configuration efficiencies are based on solid angle coverage of detectors:
  • DESCANT: 27% efficient between 1 and 5 MeV; efficiency lower outside this range, and no value is reported here.
  • SCEPTAR + ZDS: 65% efficient.
  • SCEPTAR + PACES: 40% efficient.
  • PACES + ZDS: 25% efficient.

References

• HPGe, LaBr3, SCEPTAR Simulations: E. Rand¹
• Si(Li) Simulation: T. Ma^{2, 3}, D. Cross², R. Dunlop¹, W. Mills³, Z. -M. Wang^{2, 3}, C. Andreoiu²
• Web App: W. Mills³ (source)

• ¹ University of Guelph, Guelph, ON, Canada, N1G 2W1
• ² Simon Fraser University, Burnaby, BC, Canada, V5A 1S6
• ³ TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3