Patent ID: 7058153

Claim:
A method, comprising: determining whether a specimen to be tested includes at least one positron emitter therein that will be activated in response to photon bombardment; selecting a positron emitter to be activated; determining a threshold photon energy required to activate the selected positron emitter; determining a half-life of the selected positron emitter; and when the half-life of the selected positron emitter is less than a selected half-life, then performing a rapid activation/analysis process, said rapid activation/analysis process comprising: activating for an activation time the selected positron emitter by bombarding the specimen with photons having energies at least as great as the threshold photon energy; detecting for a detection time gamma rays produced by annihilation of positrons with electrons in the specimen; and repeating said steps of activating for an activation time and detecting for a detection time until detecting a sufficient number of gamma rays to determine at least one material characteristic of said specimen; when the half-life of the selected positron emitter is greater than or equal to the selected half-life, then performing a normal activation/analysis process, said normal activation/analysis process comprising: activating the selected positron emitter by bombarding the specimen with photons having energies at least as great as the threshold photon energy; and detecting gamma rays produced by annihilation of positrons with electrons in the specimen.