Photomultiplier tube having a stress isolation cage assembly

Abstract

A photomultiplier tube comprises an evacuated envelope having a photoemissive cathode therein. A cage assembly including an anode and a plurality of closely spaced dynodes are within the envelope. The anode has at least one support rod. Each of the dynodes has a pair of dynode tabs formed in the ends thereof. A pair of dynode support spacers having a plurality of stress isolation apertures and electrode support apertures formed therethrough are provided for supporting the dynodes and the anode. The dynode tabs and the anode support rod extend through the electrode support apertures. A plurality of deformable stress isolation eyelets comprising a tubular shank with a flare formed in one end of the shank are disposed within a different one of the stress isolation apertures. The flare diameter is greater than the diameter of the stress isolation apertures thereby retaining the eyelets within the apertures. A second end of the tubular shank, opposite the flared end, extends outwardly from the dynode support spacers. The outwardly extending end portion is crimped to lock the eyelets within the stress isolation apertures. Nickel leads are provided for flexibly interconnecting the crimped end portion of a different one of each of the eyelets to one end of each of the dynodes and to one end of the anode support rod. A stem closes one end of the envelope. A plurality of relatively stiff cage assembly support leads extend through the stem and are welded to the crimped end portion of the eyelets thereby firmly securing the cage assembly to the support leads and indirectly connecting the support leads to the dynodes and the anode.