Abstract: A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

Abstract: An ion chamber exhibiting a flat response to a wide range of incident gamma energy is provided by a high-pressure fill gas mixture of a first major constituent, low atomic number gas which exhibits a reduced gamma response at low gamma energy levels, and a second minor constituent, high atomic number gas which exhibits an increased gamma response at low gamma energy levels. The preferred fill gas mixture is nitrogen as the major constituent and xenon as the minor constituent.

Abstract: The radioactivity of radioactive fluid is monitored, in the presence of background radiation, without interruption of radioactivity detection with two successive volumes of radioactive fluid, the background being eliminated by subtraction. Typically the intrinsic responses are in the ratio of two to one for such successive measurements, when the proper volumes have been selected.

Abstract: A self-powered nuclear radiation detector with an emitter electrode of an alloy of a first major constituent metal having a desired high radiation response, and a second minor constituent which imparts to the alloy a desired thermal or mechanical characteristic without diminishing the desired high radiation response. A gamma responsive self-powered detector is detailed which has an emitter with lead as the major constituent, with the minor constitutent selected from aluminum, copper, nickel, platinum, or zinc.

Abstract: An emitter plate of a high atomic number material is positioned between collector plates of a low atomic number material and the ionization current developed in the gap regions therebetween in response to low radiation fields and the self-powered current developed in response to high radiation fields is measured by a current measuring circuit as an indication of impinging radiation.

Abstract: A self-powered neutron detector in which two electrically isolated emitter electrodes are provided. The emitters are formed of different materials having differing responses to thermal and epithermal neutron flux. The separate signals generated between the separate emitters and a common collector electrode are used to determine the respective thermal and epithermal neutron fluxes for a more accurate flux mapping of the reactor core.

Abstract: A more reliable self-powered radiation detector structure and method of manufacture is provided by a detector structure in which a relatively ductile centrally disposed conductive emitter wire supports and is in electrical contact with a generally tubular emitter electrode. The detector is fabricated by swaging and the ductile center wire insures that electrical discontinuities of the emitter are minimized.

Abstract: An improved response gamma sensitive self-powered detector is provided by forming the conductive central emitter as a tubular member. Low density, non-attenuating insulating means is disposed within the tubular emitter and about the tubular emitter spacing it from the coaxial outer conductive collector.

Abstract: A self-powered radiation detector of improved sensitivity is provided by having a tubular emitter electrode, with an inner collector electrode coaxial within the tubular emitter and insulated therefrom, and an outer tubular collector electrode coaxial about and insulated from the tubular emitter. The inner and outer collector electrodes are electrically connected.

Abstract: An improved compensated self-powered neutron detector is detailed wherein a thin conductive layer of low neutron cross section, high density material is disposed about the emitter core and also on the interior of the collector sheath. The conductive layer about the emitter absorbs low average energy electrons produced by emitter material activation products. The provision of the inner and outer conductive shield layers insures that signal current due to the response of these shielding layers to external gamma rays will be nullified and the detector device compensated to provide a detector which primarily responds to neutrons.

Abstract: A neutron activation probe comprises a pulsed neutron source in series with a plurality of delayed neutron detectors for measuring radioactivity in a well borehole together with a NaI (T1) counter for measuring the high energy 2.62 MeV gamma line from thorium. The neutron source emits neutrons which produce fission in uranium and thorium in the ore body and the delayed neutron detectors measure the delayed neutrons produced from such fission while the NaI (Tl) counter measures the 2.62 MeV gamma line from the undisturbed thorium in the ore body. The signal from the NaI (T1) counter is processed and subtracted from the signal from the delayed neutron detectors with the result being indicative of the amount of uranium present in the ore body.

Abstract: A self-powered gamma flux sensitive detector has improved gamma sensitivity as a result of provision of a low density insulating means between the emitter and collector of the detector.

Abstract: A coaxial electrical signal cable is inherently compensated for gamma flux induced currents by the use of selected alloys for the central conductive wire. The central conductive wire alloy comprises a first metal which interacts with the gamma flux to produce a negative current contribution between the central conductive wire and the conductive sheath, and a second metal which interacts with the gamma flux to produce a positive current contribution, which in combination with the signal produced in the conductive sheath results in a null gamma induced current for the cable.