Gamma Plot Options

Min E (keV)

Max E (keV)

Energy Scale: linear log

Min Effic.

Max Effic.

Effic. Scale: linear log

Array configuration:

No. HPGe

HPGe Distance

HPGe Addback:

BGO Shields:

Delrin Absorbers

Save Plot

Save CSV

Beta Plot Options

at keV and BR +

at keV and BR,

with beam intensity pps,

and duty cycle %:

Efficiency: 0.00

Detected Events: 0.00

Or counts accrue in 0.00 s

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. Ma^{2, 3}, D. Cross², R. Dunlop¹, W. Mills³, Z. -M. Wang^{2, 3}, C. Andreoiu²
Web App: Built by W. Mills³ (source), and maintained by A. Garnsworthy³