Scintillation detector and method of making

A method of assembling a detector includes conditioning a rare-earth halide scintillator crystal in a sealed container, wherein the conditioning process includes heating the scintillator crystal, reducing the pressure within the sealed container for an evacuation period while heating, and flowing a purging gas through the sealed container for a flowing duration while heating. The method further includes assembling a detector comprising the scintillator crystal in an assembly environment comprising an inert gas.