Method for fabricating .sup.99 Mo production targets using low enriched uranium, .sup.99 Mo production targets comprising low enriched uranium

A method for fabricating a primary target for the production of fission products comprising:

• choosing a first substrate having a first substrate first surface, a first substrate first end, a first substrate first raised shoulder of a predetermined height integral to said first substrate first end, a first substrate second end, a first substrate second raised shoulder of a predetermined height integral to said first substrate second end, a first substrate second surface, a first substrate peripheral edge, a first substrate predetermined thickness, a depressed surface between said first substrate first raised shoulder and said first substrate second raised shoulder, and a longitudinal welding rib, having a predetermined height, a first side surface and a second side surface, integrally attached to the first substrate first surface, the first substrate first raised shoulder and the first substrate second raised shoulder;
• preparing the first substrate first surface to receive a foil of fissionable material, said foil of fissionable material having a first foil surface, a second foil surface, a first side surface, a second side surface and a predetermined thickness;
• circumferentially contacting the foil first surface with the depressed surface of the first substrate first surface, so as to allow for later removal of the foil from the first substrate;
• abutting the first side surface and second side surface of said foil of fissionable material against the first side surface and second side surface of the longitudinal welding rib;
• choosing a second substrate having a second substrate first surface, a second substrate second surface, a second substrate peripheral edge, a second substrate first end, a second substrate second end, a slit extending longitudinally the entire length of the second substrate from the second substrate first end to the second substrate second end, wherein the slit has opposing edges, and a second substrate predetermined thickness;
• preparing the second substrate first surface to receive the foil second surface so as to allow for later removal of the foil from the second substrate;
• attaching the first substrate peripheral edge to the second substrate peripheral edge such that the first substrate second surface and the second substrate second surface are exposed to ambient atmosphere, wherein the foil is sandwiched between the first substrate and second substrate to prevent foil exposure to ambient atmosphere and the opposing edges of said slit overlay the longitudinal welding rib of the first substrate;
• compressing the exposed first substrate second surface and the second substrate second surface to assure physical contact between the foil and the first substrate first surface and between the foil and the second substrate first surface;
• sizing the first substrate raised shoulders so that the predetermined heights of the first substrate first raised shoulder and the first substrate second raised shoulder are of the same height relative to the first substrate first surface, thereby creating a depressed center section coextensive with the depressed surface of said first substrate;
• sizing the welding rib so that the predetermined height of the welding rib is commensurate with the predetermined thickness of the foil of fissionable material, wherein said foil abuts against the first and second side surfaces of said welding rib to retain the foil within the depressed center section;
• welding the opposing edges of the slit of said second substrate to the rib of said first substrate.

A primary target for the production of fission products, comprising:

• a.) an inner cylinder having an interior surface, an exterior surface, a first end, a second end, a first raised shoulder at the first end, and a second raised shoulder at the second end;
• b.) a raised welding rib forming an integral part of said inner cylinder and extending longitudinally from the first raised shoulder to the second raised shoulder, said welding rib having a top surface, a first side surface, and a second side surface;
• c.) a foil of fissionable material having a first surface, a second surface, a first edge, and a second edge which opposes the first edge, wherein the length from the first edge to the second edge is less than the circumference of the inner cylinder exterior surface, and whereby said foil forms a layer on the inner cylinder exterior surface so that the foil first surface contacts the inner cylinder exterior surface, the foil first edge abuts against the welding rib first side surface, and the foil second edge abuts against the welding rib second side surface;
• d.) an outer cylinder having an interior surface, an exterior surface, a first end, a second end, and a slit extending longitudinally from the outer cylinder first end to the outer cylinder second end, the slit having a first edge and a second edge, whereby the outer cylinder forms a layer on the foil such that the outer cylinder interior surface contacts the foil second surface, the outer cylinder first end contacts the inner cylinder first raised shoulder, the outer cylinder second end contacts the inner cylinder second raised shoulder, and the slit first edge and the slit second edge are aligned over the welding rib top surface;
• e.) first means for attaching the outer cylinder slit edges to the welding rib top surface;
• f.) second means for attaching the outer cylinder first end to the inner cylinder first raised shoulder and the outer cylinder second end to the inner cylinder second raised shoulder, whereby said foil is contained between the inner and outer cylinders.