A scintillator includes a support substrate, an emission layer formed on the substrate, made of ZnO with impurities added to have an electron concentration of 2?10.sup.19 cm.sup.?3 or more and 2?10.sup.20 cm.sup.?3 or less, and for generating scintillation light in response to incidence of radiation, a protective layer formed on the emission layer and made of a material having a band gap wider than that of ZnO, and a metal layer formed on the protective layer. The support substrate is made of a material transmitting the scintillation light generated in the emission layer. Further, the metal layer functions as a reflection layer for reflecting the scintillation light from the emission layer.

An ion pump has an exterior magnet and a chamber wall defining an interior. The interior contains an anode having an exterior surface extending around an axis and defining an opening wherein the axis passes through the opening and a post made of ferrous material, aligned with the axis of the anode and positioned between the exterior magnet and the anode.

A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.