Y-Ba-Cu-O superconductor containing radioactive dopants
AssigneeGeneral Electric Company
InventorRobert L. Fleischer
Life of this patent
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Abstract
A polycrystalline Y-Ba-Cu-O superconductor doped with sufficient .sup.235 U and/or .sup.239 Pu atoms is irradiated with thermal neutrons to produce from about 2.5.times.10.sup.14 to about 50.times.10.sup.14 fission events per cubic centimeter of superconductor.
Claims17
A process for producing a superconductive body which comprises providing a matrix-forming powder of oxides or precursor therefor wherein the oxide composition corresponds to the matrix composition comprised of YBa.sub.2 Cu.sub.3 O.sub.7-y where y ranges from zero to about 1, providing an oxide additive or precursor therefor selected from the group consisting of natural uranium dioxide, uranium-235 dioxide, plutonium -239 dioxide and mixtures thereof, all of the uranium component of said additive and all of the plutonium-239 component of said additive providing dopant atoms, said natural uranium dioxide providing dopant atoms comprised of natural uranium which includes the uranium-235 isotope, forming a mixture of said matrix-forming powder and said additive or precursor therefor, heating said mixture to a reaction temperature ranging from greater than about 800.degree. C. to below the melting point of said oxides to produce a reaction product comprised of said matrix composition and said dopant atoms wherein said dopant atoms being substituted in said matrix composition in an amount ranging to their solubility limit therein, said precursors decomposing below said reaction temperature producing said oxides, comminuting said reaction product to produce a sinterable powder, forming said sinterable powder into a compact, sintering said compact in an oxidizing atmosphere at a temperature ranging from about 900.degree. C. to below the melting point of said sinterable powder producing a sintered polycrystalline body having an open porosity ranging from zero to about 20% by volume of said body, cooling said body in an oxidizing atmosphere at a rate which produces a superconductive body and irradiating said superconductive body with thermal neutrons causing a sufficient number of said uranium-235 and/or plutonium-239 dopant atoms to undergo fission to produce from about 2.5.times.10.sup.14 to about 50.times.10.sup.14 fission events per cubic centimeter of the resulting irradiated superconductive body, said uranium-235 and/or plutonium-239 dopant atoms being present in an amount sufficient to produce said fission events.
A superconductive polycrystalline body comprised of the composition YBa.sub.2 Cu.sub.3 O.sub.7-y, where y ranges from zero to about 0.3, and dopant atoms selected from the group consisting of natural uranium, .sup.235 U, .sup.239 Pu, and mixtures thereof, said natural uranium atoms ranging from a detectable amount to less than 380 atomic parts per million atomic parts of said body, said .sup.235 U atoms ranging from a detectable amount to less than about 380 atomic parts per million atomic parts of said body, said .sup.239 Pu atoms ranging from a detectable amount to less than about 380 atomic parts per million atomic parts of said body, said dopant atoms being substituted in said composition in an amount ranging to their solubility limit therein, said body containing from about 2.5.times.10.sup.14 to about 50.times.10.sup.14 fission events per cubic centimeter of said body.
Dependencies are inferred from the claim text.