Container inspection system and method

Claim 2

An improved relatively compact, sealed radioisotope source of low energy gamma for use in nuclear gauging apparatus wherein various materials are inspected, comprising a housing of a metal tending to have impurities present as a result of the processing of such metal, said housing including means defining a first and second formed cavity at opposite ends thereof, one of said cavities including a bottom wall and being in a portion of said housing substantially free of impurities, the other of said cavity being so positioned that the bottOm wall thereof is located in a portion of the housing tending to be substantially free of impurities while the cavity is formed in that portion of the housing tending to be the area of relatively high concentration of impurities, said cavities being spaced from each other such that the spaced respective bottom walls form a thin low energy gamma transmitting window which is integral with said housing, a source of radioactive material so sealed in said first cavity adjacent to said window as to provide low energy gamma radiation which passes through said window, said window being substantially free of metallic impurities tending to cause leakage of said source material from said first cavity, and movable means in said second cavity for alignment with said window in one position for collimating the emanating radiation and for blocking the passage of radiation in a second position thereof.

Claim 3

In an apparatus as set forth in claim 1 further including shield means in said first cavity at a position external to the source material and sealed to the housing to prevent leakage of source material from the housing through the first cavity and blocking all radiation through the first cavity so that emanating radiation passes only through said integral window.

Claim 4

In an apparatus as set forth in claim 1 wherein said movable means includes a bar movably disposed in said second cavity and including a collimating aperture for alignment with the window, in one slidable position of the bar, to provide for passage of gamma rays from the source through the window and aperture.

Claim 5

In an apparatus as set forth in claim 1 wherein said source material is an Americium-241 radioisotope.

Claim 6

In an apparatus as set forth in claim 1 wherein said housing is of low carbon vacuum melted stainless steel.

Claim 7

In an apparatus as set forth in claim 5 wherein said steel is a Type 304 stainless steel.

Claim 8

In an apparatus as set forth in claim 1 wherein said window has a thickness of less than 0.01 inches.

Claim 9

In an apparatus as set forth in claim 7 wherein said window has a thickness of 0.006 inch.

Claim 10

In an apparatus as set forth in claim 2 wherein said shield means includes a first shield adjacent to the source and sealed to the housing and a second shield overlying said first shield and sealed to said housing.

Claim 11

In an apparatus as set forth in claim 1 wherein said housing is made from rolled bar stock, said second cavity and said window being located in that portion of said bar stock containing the minimum, if any, metallic impurities.

Claim 12

An improved compact radioactive source for use in nuclear gauging wherein the emitted radiation is low energy gamma, comprising a metal housing having a portion thereof of reduced metal impurities and defects, and a portion tending to include a relatively high concentration of metal impurities and defects, means forming a first cavity including a bottom wall in that portion of the housing of reduced metal impurities, a second cavity so positioned as to be opposite said first cavity and oriented such that the bottom wall thereof is spaced from the bottom wall of the first cavity, the bottom wall of said second cavity being in a portion of said housing substantially free of impurities and said second cavity being located in a portion of said housing tending to have a relatively high concentration of metal impurities, said cavities being spaced from each other such that the spaced bottom walls thereof define a relatively thin window integral with said housing and being that portion of said housing separating said first and said second cavities, a source of radioactive material received in said second cavity and positioned adjacent to said window, means sealing said radioactive material in said second cavity whereby gamma radiation emanating therefrom passes through said window, and collimating means positioned in sAid first cavity and movable to a position in alignment with said window for collimating said emanating gamma radiation and being movable to another position obstructing emanation of gamma radiation from said housing.

Claim 13

An improved compact radioactive source for use in nuclear gauging wherein the emitted radiation is low energy gamma, comprising a metal housing having a portion thereof of reduced metal impurities and defects, and a portion tending to include a relatively high concentration of metal impurities and defects, means forming a first cavity including a bottom wall in that portion of the housing of reduced metal impurities, a second cavity so positioned as to be opposite said first cavity and oriented such that the bottom wall thereof is spaced from the bottom wall of the first cavity, the bottom wall of said second cavity being in a portion of said housing substantially free of impurities and said second cavity being located in a portion of said housing tending to have a relatively high concentration of metal impurities, said cavities being spaced from each other such that the spaced bottom walls thereof define a relatively thin window integral with said housing and being that portion of said housing separating said first and said second cavities, a source of radioactive material received in said second cavity and positioned adjacent to said window, means sealing said radioactive material in said second cavity whereby gamma radiation emanating therefrom passes through said window, and collimating means positioned in sAid first cavity and movable to a position in alignment with said window for collimating said emanating gamma radiation and being movable to another position obstructing emanation of gamma radiation from said housing.