Abstract:
A position sensitive fast timing detector for determining time-of-flight mass analysis and position of atomic particles includes a channel plate assembly for detecting the impact of one or more atomic particles a transforming them into one or more electron clouds. The electron cloud then passes through an electron detector which includes a meandric delay line located in front of a back plate. A second meandric delay line may also be utilized, wherein the second delay line is orthogonal with the first delay line. A grid may be placed between the first and second meandric delay lines to reduce cross-talk.
Abstract:
A device for forming images of ionizing particles through single-dimensional electrophoresis provided with a multi-wire proportional chamber. The chamber filled with a gas is of asymmetric structure and is formed successively by an entry window for the particles, taken to a negative potential, a multi-wire anode electrode, taken to a potential positive with respect to a reference potential, and a cathode electrode which is placed in the vicinity of the anode electrode. The cathode electrode, which is taken to the reference potential, is formed by a network of parallel electrically conducting strips. Detection of the position of impact of the ionizing particle along the pitch of the network is performed by induction of a delayed electric pulse caused by an avalanche of the ionization electrons issuing from the ionizing particle in the region of the strip situated in line with the impact by the particle in the chamber, the reference time being that of the ionization electrons close to the wires.
Abstract:
An electrostatic deflector for energy selection of a beam of charged particles has a plurality of main deflector plates arrayed in a generally cylindrical basic shape and to which electrostatic potentials are applied. The main deflector plates are shaped and the potentials are applied to generate a path of said beam from an input side of said deflector to an output side thereof by virtue of a deflecting field which is increasingly weakened to both sides of a central portion of the beam toward the main deflector plates relative to a field of ideal cylindrical shape, thereby causing second order angular aberration of the beam to substantially vanish. A pair of end deflector plates at opposite ends of the cylindrical basic shape have a repulsive potential with respect to the beam to effect focussing of the beam perpendicular to a dispersion plane of the deflector.
Abstract:
A method for fabricating an ion chamber dosimeter collecting array of the type utilizing plural discrete elements formed on a uniform collecting surface which includes forming a thin insulating layer over an aperture in a frame having surfaces, forming a predetermined pattern of through holes in the layer, plating both surfaces of the layer and simultaneously tilting and rotating the frame for uniform plate-through of the holes between surfaces. Aligned masking and patterned etching of the surfaces provides interconnects between the through holes and copper leads provided to external circuitry.
Abstract:
A detection medium for a kinestatic charge detector is a mixture of gases, typically including at least one noble gas such as zenon or krypton. The medium can be pressurized to improve resolution and temperature can also be applied to the medium for improving resolution. Various additive or dopant gases can also be introduced to improve resolution.
Abstract:
In an electron spectrometer, electrons emanating from a source are collected and focused to a collimated stream by an electrostatic lens free of spherical aberration. The lens includes a pair of axially spaced concave grids approximating sections of concentric ellipsoids having a common focii and coaxial semi-major axes. The collimated electron stream is inducted into an electric radial cylindrical analyzer for focusing the electrons into radially dispersed lines on a position-sensitive detector with the radial dispersion being a function of their energies. The cylindrical analyzer section subtends an angle of approximately 63.5.degree.. The grid openings in the grids of the electrostatic collimating lens are elongated in a direction transverse to the stream of the electrons passing therethrough and parallel to the radial electric field lines at the entrance to the electric analyzer to reduce the dispersive effect of the grids.
Abstract:
In order to provide an ionization-type smoke detector, wherein the radiation from a radioactive source mounted on the inner electrode disposed within the inner ionization chamber also reaches into the outer ionization chamber through a through-hole formed in the intermediate electrode, which is easy to assemble and which has a constitution to prevent scattering of the radioactive source even though inner and outer ionization chambers are provided with the insulation base board for supporting the inner and intermediate electrodes at a predetermined spacing is connected to the printed circuit board by a mounting rod, and the outer electrode surrounding the intermediate electrode and the insulation base board with smoke inlet openings is connected at its end periphery to the printed circuit board, the printed circuit board being connected to the base of the detector by connecting pins.
Abstract:
Proportional counters for the detection and measurement of radioactive surface contaminations are provided with at least two flat window faces enclosing an angle and being formed by a thin foil spread or stretched by a framework including thin rods arranged along the inner edges of contacting window faces, to which rods the foil may be adhered. A perforated lattice or grid cage serves in particular to protect the thin window against any contact, the cage provides for a spacing of about double rod thickness between the framework and the controlled surface. Preferred is a polygonal and in particular hexagonal lattice whose grid wires or strips do not lie in the main scanning direction. Particularly convenient for checking pipelines are, for example, cylindrical measuring probes comprising window foils extending over and perhaps adhered to a circularly arranged frame of thin rods.
Abstract:
To enable an ionization chamber used for measuring the intensity of a beam of ionizing radiation, for example an electron beam produced by a linear accelerator and used for radiotherapy, both to give an output signal which is independent of ambient pressure and temperature and to present a low weight of scattering material per unit area to the beam, the chamber is of flexible construction so that the volume of gas in it adapts to ambient pressure and temperature, and such that the weight of gas in the active region between the electrodes per unit area remains substantially constant. Suitably, the electrodes are conductive layers on flexible plastics sheets, an outer annular portion of one sheet providing a flexible connection between two opposed chamber wall portions which remain substantially planar and parallel; the proportional change (.DELTA.V.sub.1 /V.sub.1) in a volume bounded by the opposed wall portions and including the active region equals the proportional change (.DELTA.V.sub.2 /V.sub.2) in the remainder (V.sub.2) of the internal volume.
Abstract:
A pressure vessel of an X-ray detector, in which the contamination and leakage of xenon gas contained in the detector is prevented. The pressure vessel of the invention comprises a container of a curved pillar shape with a window through which the X-ray passes. The container is made of a metal, and the window faces inward of the curvature of the container. A carbon fiber-reinforced plastic sheet is fixed to the inner wall of the periphery of the window to cover the window. An elastic insulation sheet is attached to the inside of the carbon fiber-reinforced plastic sheet so as to cover the window. A metal foil is attached to the inside of the elastic insulation sheet so as to cover the window.