# US 4,400,621 A · Detector device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,621 A - Document ID: US4400621A - Status: Granted - Kind: A - Application number: 06/230,505 - Filed: 1981-02-02 - Granted: 1983-08-23 - Earliest claimed: 1980-02-02 - Assignees: Kernforschungszentrum Karlsruhe GmbH - Inventors: Hans Kiefer; Hans-Gerd Rober - Web page: https://patentgrep.com/patent/US4400621A ## CPC - G01T 1/18: with counting-tube arrangements, e.g. with Geiger counters (tubes H01J47/08; {with alarm provision G01T7/125}) - G01T 1/38: Particle discrimination and measurement of relative mass, e.g. by measurement of loss of energy with distance (dE/dx) - B60T 2240/08: Spare wheel detection; Adjusting brake control in case of spare wheel use - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES ## Abstract A device for simultaneously detecting alpha and beta particles which comprises a detector element, amplification means coupled to the output of the detector element and measuring means coupled to the output of the amplification means. The alpha and beta particles which impinge on the detector element exhibit different ionization densities, and this results in a voltage being generated at the output of the amplification means which has a rise time and amplitude corresponding to the type of particle impinging on the detector element. The measuring means measures at least the rise time of the voltage at the output of the amplification means, the rise time being different for the alpha and beta particles and providing a means for distinguishing between the two types of particles. ## Claims ### Claim 1 A device for simultaneously detecting alpha and beta particles comprising a detector element for detecting both alpha and beta particles impinging thereon, said alpha and beta particles exhibiting different ionization densities; and amplification means coupled to the output of said detector element, said amplification means generating a voltage at its output having a rise time and amplitude corresponding to the type of particle impinging on said detector element, said rise time being different for said alpha and beta particles and providing a means for distinguishing therebetween. ### Claim 2 (depends on 1) A device as defined in claim 1 wherein said detector element is a proportional counting tube. ### Claim 3 (depends on 1, 2) A device as defined in claim 1 or 2 wherein said detector element is a large area counting tube having at least one counting wire. ### Claim 4 (depends on 3) A device as defined in claim 3 wherein the capacitance of said counting wire is less than 20 pF. ### Claim 5 (depends on 1, 2) A device as defined in claim 1 or 2 which further comprises at least one control radiator adjacent said detector element, said control radiator including a radiation source and an adjustable diaphragm interposed between said radiation source and said detector element. ### Claim 6 (depends on 3) A device as defined in claim 3 which further comprises at least one control radiator adjacent said counting tube, said control radiator including a radiation source and an adjustable diaphragm interposed between said radiation source and said counting tube. ### Claim 7 A device for simultaneously detecting alpha and beta particles comprising a proportional counting tube comprising a plurality of parallel wires connected together at one end for detecting both alpha and beta particles impinging thereon, said alpha and beta particles exhibiting different ionization densities; a high voltage source; an operational amplifier having a first input coupled to said one end of the plurality of wires comprising said counting tube and to said high voltage source, said amplifier generating a voltage at its output having a rise time corresponding to the type of particle impinging on said counting tube; and measuring means coupled to the output of said amplifier for measuring the rise time of the voltage at the output of said amplifier, said rise time being different for said alpha and beta particles and providing a means for distinguishing therebetween. ### Claim 8 (depends on 7) A device as defined in claim 7 wherein the first input of said amplifier is coupled to positive and negative voltage sources through first and second diodes respectively, said first diode being poled to permit flow of current away from the first input of said amplifier and said second diode being poled to permit flow of current toward the first input of said amplifier. ### Claim 9 (depends on 7, 8) A device as defined in claim 7 or 8 wherein the output of said amplifier is coupled to a second input thereof. ### Claim 10 (depends on 7, 8) A device as defined in claim 7 or 8 which further comprises a resistor connected in series with each of said plurality of parallel wires comprising said counting tube.