GRIFFIN Efficiency Calculator
- HPGe GEANT4 Simulation: 8th order polynomial fit including selected 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 to match the empircal online performance observed in 2018/2019 beamtimes of 2%.
- 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: 80% efficient for beta tag.
- SCEPTAR + PACES: 40% efficient for beta tag.
- PACES + ZDS: 40% efficient for beta tag.
- For more details of the GRIFFIN spectrometer see the NIM Article and (GRIFFIN website)
- HPGe Simulations: Originally developed by E. Rand1, different configurations simulated by A. Ibrahim1 and M. Stuck1 with oversight from C. Svensson1
- LaBr3, SCEPTAR Simulations: E. Rand1
- Si(Li) Simulation: T. Ma2, 3, D. Cross2, R. Dunlop1, W. Mills3, Z. -M. Wang2, 3, C. Andreoiu2
- Web App: Built by W. Mills3 (source), and maintained by A. Garnsworthy3
- 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