Ionization chamber having coaxially arranged cylindrical electrodes
AssigneesMitsubishi Denki Kabushiki Kaisha, Japan Atomic Energy Research Institute
InventorsNaoki Wakayama, Hideshi Yamagishi, Toshimasa Tomoda, Hiroji Tanaka
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Abstract
An ionization chamber comprises a plurality of cylindrical electrodes which are coaxially arranged, and a casing which holds the cylindrical electrodes in it under the condition allowing the axial shifting of the edges of the cylindrical electrodes but preventing the radial shifting of the cylindrical electrodes whereby the slight relative deviation of parts for the ionization chamber can be minimized during use at high temperature or during a severe thermal cycle.
Claims8
In an ionization chamber comprising a plurality of coaxially arranged cylindrical electrodes and a casing containing an ionizable gas which holds said cylindrical electrodes, and an output terminal for transmitting electric signals through said casing, an improvement wherein said cylindrical electrodes are held in said casing so as to allow axial shifting of the edges of said electrodes but to prevent radial shifting of said electrodes;
- wherein said output terminal is formed by metal-ceramic sealing means which includes a cylindrical sealing metal part bonded on an outer surface of a cylindrical ceramic part;
- and wherein the outer surface of said cylindrical sealing metal part is formed to have a tapered portion whose thickness is gradually decreased to an edge of said sealing metal part;
- whereby thermal stresses within said output terminal are minimized.
In an ionization chamber comprising a plurality of coaxially arranged cylindrical electrodes and a first casing containing an ionizable gas, an output terminal made of metal-ceramic sealing means passing through said first casing for transmitting electric signals through said casing, and a second casing which covers at least a portion of said output terminal and at least a portion of said first casing, an improvement wherein said cylindrical electrodes are held in said first casing so as to allow axial shifting of the edges of said electrodes but to prevent radial shifting of said electrodes and said second casing is filled with a gas at a pressure substantially the same as the pressure of an ionizable gas filling said first casing.
An ionization chamber comprising:
- inner and outer cylindrical electrodes arranged coaxially;
- a sealed casing containing an ionizable gas within which said inner and outer cylindrical electrodes are disposed;
- means disposed within said casing for securing said inner and outer electrodes within said casing such that at least one axial end surface portion of each of said inner and outer electrodes is free from axial contact with and axial restraint from said securing means and for allowing substantially free unimpeded axial movement of said at least one end surface portion and such that radial shifting of said inner and outer electrodes is prevented by said securing means.
Dependencies are inferred from the claim text.