Abstract: A scintillation detector assembly sealed via a compression fit without the use of epoxy or other sealant is disclosed. The assembly includes a scintillator composition and a photomultiplier tube optically coupled to the scintillator. A hermetically sealed scintillator container assembly in accordance with the present disclosure includes a cup shaped container sized to receive and hold a scintillator composition. This container has an open end. A metal rim compressively forms a mechanical hermetic seal around a glass window placed over the open end to preclude moisture intrusion into the container and thus prevent exposure of the scintillator crystalline material to degrading moisture. The metal rim is in turn welded to the container.