Guard efficiency compensation system and method

A radiation detection system comprising:

• a liquid scintillator configured to detect events in a beta spectrum;
• a crystal scintillator guard configured to detect events in a gamma spectrum;
• one or more processors adapted to:
• mathematically transform the gamma spectrum into a spectrum that follows a Compton backscatter profile that approximates a SP12 spectrum;
• and
• count coincident events between the beta spectrum and the transformed gamma spectrum for one or more energy regions and count non-coincident events that are only in the beta spectrum;
• and
• for each energy region
• calculate a compensation crystal scintillator guard count based on the count of coincident events and a predetermined crystal scintillator guard efficiency value associated with the energy region,
• calculate a correction value that is based on the compensation crystal scintillator guard count and the counts of coincident and non-coincident events, and
• correct counts of non-coincident events in the beta spectrum and corresponding to the energy region based on the calculated correction value.

A radiation detection system comprising:

• a scintillator configured to detect sample events;
• a guard detector subsystem configured to detect active guard events;
• one or more processors adapted to:
• count coincident events that are the sample events and the active guard events detected coincidently in one or more energy regions and count non-coincident events that are the sample events detected when the active guard events are not coincidently detected, wherein the count is based on utilization of an unknown sample;
• and
• for each energy region:
• calculate a compensation guard count based on the count of coincident events and a predetermined guard efficiency value associated with the energy region based on utilization of a standard sample having a quench level.