Abstract:
A dosimeter is described that does not show differences in sensitivity over its sensitive area when the ambient pressure changes. To that purpose the measuring chamber and a pressure compensation element together form a single gas tight chamber having at least partially of slack material, wherein the pressure inside the measuring chamber is essentially equal to ambient pressure such that no mechanical distortion of the measuring chamber over its sensitive area takes place.
Abstract:
A detector for bremsstrahlung-isochromatic-spectroscopy (BIS) utilizing a gas-filled metal cylinder forming an outer electrode and a wire extending axially in the cylinder has an inner electrode. The window for the UV photons is constituted of MgF.sub.2 while the counting gas is a mixture of dimethylether and an inert gas and in which the pressure of the dimethylether is 0.2 to 0.5 mbar.
Abstract:
A radiation counter comprises; electrodes made of nickel base super alloy containing the nickel in the weight ratio exceeding 30% and not exceeding 90% and the chrome, the iron, etc. as the balance; and counter gas in which the argon gas is the chief ingredient and with which the nitrogen gas is mixed in the volume ratio exceeding 2% and not exceeding 30%. The counter operates stably at a high temperature exceeding 450.degree. C., affords relatively large output pulse current and has short electron-collection-time characteristics.
Abstract:
Improved binary and tertiary gas mixtures for gas-filled particle detectors are provided. The components are chosen on the basis of the principle that the first component is one gas or mixture of two gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a gas (Ar) having a very small cross section at and below aout 0.5 eV, whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electron field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.
Abstract:
A muon detector includes: a chamber having a maximum cross-sectional dimension of 30 cm or less; a gas sealed inside the chamber ionized by the passage of atmospheric muons to form ions in the chamber; a cathode in the chamber at a first position; an anode in the chamber displaced from the first position, the anode including a mesh of wires; a micropattern gaseous detector arranged between the cathode and the anode and proximate to the anode and configured to receive the ions formed in the chamber between the anode and the cathode and generate electrons in response to each ion sufficient to generate a current in one or more of the mesh wires of the anode; and readout electronics in electrical communication with the anode to detect signals in response to the current generated in the mesh wires.
Abstract:
A probe assembly is disclosed comprising an inlet for receiving an eluent from a chromatography device; an outlet (120) for delivering the eluent to an ion source of a mass spectrometer; and an attachment device (122) for attaching the outlet to the mass spectrometer. The outlet comprises an electrically conductive capillary (124) and an electrically conductive member (129) surrounding at least part of the electrically conductive capillary (124). The electrically conductive member (129) is arranged to receive a voltage upon connection of the attachment device (122) to the mass spectrometer and the electrically conductive member (129) is arranged to provide an electrical connection from the electrically conductive member (129) to the electrically conductive capillary (124).
Abstract:
A direct ion storage (DIS) radiation detector or dosimeter has a design that is easy and low cost to manufacture using semiconductor processing techniques. The detectors include internal communications interfaces so they are easy to read. Different interfaces, including wired, e.g. USB ports, and wireless interfaces, may be used, so that the dosimeters may be read over the internet. The detectors can thus be deployed or used in a variety of detection systems and screening methods, including periodic or single time screening of people, objects, or containers at a location by means of affixed dosimeters; screening of objects, containers or people at a series of locations by means of affixed dosimeters, and surveillance of an area by monitoring moving dosimeters affixed to people or vehicles.
Abstract:
A direct ion storage (DIS) radiation detector or dosimeter has a design that is easy and low cost to manufacture using semiconductor processing techniques. The detectors include internal communications interfaces so they are easy to read. Different interfaces, including wired, e.g. USB ports, and wireless interfaces, may be used, so that the dosimeters may be read over the internet. The detectors can thus be deployed or used in a variety of detection systems and screening methods, including periodic or single time screening of people, objects, or containers at a location by means of affixed dosimeters; screening of objects, containers or people at a series of locations by means of affixed dosimeters, and surveillance of an area by monitoring moving dosimeters affixed to people or vehicles.
Abstract:
A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization.An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0.degree. to 30.degree. C.
Abstract:
A Geiger-Mueller tube includes a tubular, stainless steel cathode (A) which defines a chamber (B) therein. An anode (C) extends axially through the chamber in a spaced relationship with the cathode. A thin layer of rhenium (20) is plated on an interior surface (12) of the cathode. End caps (32, 36) and ceramic fittings (34, 38) hermetically seal the ends of the cathode tube. The cathode chamber is charged with a gaseous mixture including in primary part noble gases, such as neon and argon, and about 1-3% bromine or other halogen gases. The Geiger-Mueller tube with a rhenium plated cathode is relatively inexpensive to manufacture, provides excellent bromine and halogen degradation resistance at elevated temperatures, and provides superior, linear operating characteristics over a wide range of temperatures.