[en] A pulsed neutron source arrangement is provided in which a sealed cylindrical chamber encloses a rotatable rotor member carrying a plurality of elongated target strips of material which emits neutrons when bombarded with alpha particles emitted by the plurality of source material strips. The rotor may be locked in a so-called ON position by an electromagnetic clutch drive mechanism controllable from the earth's surface so as to permit the making of various types of logs utilizing a continuously emitting neutron source. (Patent Office Record)

No abstract available

No abstract available

[en] The method described comprises the steps of bombarding the earth formation surrounding the borehole with pulses of fast neutrons, generating electrical signals functionally related to the gamma radiation emanating from the formation and making a time-dependent selection of those pulses attributable by amplitude to gamma rays occurring from inelastic scattering of neutrons by carbon and oxygen nuclei and excluding pulses attributable by amplitude to carbon and oxygen background radiation occurring from fast neutron processes. Finally, a ratio of the function of those selected pulses relating to carbon nuclei to a function of those selected pulses relating to the oxygen nuclei are derived. (Patent Office Record)

[en] A system for real-time neutron radiography of moving objects is described. It comprise a source adapted to generate a continuous uninterrupted series of neutron pulses. Each pulse has a predetermined peak power and duration compatible with the framing times of a real-time video imaging system. A transporter moves an object to be examined to bring sequentially position selected portions of the object in the path of the pulses. Where the object itself has moving components, pulses are sequentially incident on the object. According to any dissimilarities, the object will alter the intensity of the neutrons passing therethrough. In order to record separately the changes in the neutron intensity, for each pulse, an imager is positioned to receive the neutron beam pulses which have been altered by their passage through the object and produce images indicating intensity alterations. A refrigerated beryllium filter can be used to effectively eliminate thermal neutrons from the pulses and produce short duration cold neutron radiographic images. The neutron pulses may be generated by raising and lowering control rods or by rotating a wheel having fuel regions and poison regions with respect to a reactor. (author)

No abstract available

[en] The techniques employed consists in producing, according to time, a phase-coherent and intensity-modulated fast neutron cloud in a bore hole. When these fast neutrons are slowed down by the substances in the vicinity of the bore hole, their energy is converted into heat energy and they bring about the formation of a phase-coherent cloud of thermal neutrons. The determination of the relative phase of the population density of the thermal neutron cloud in relation to that of the cloud of fast neutrons produced, permits the determination of the parameters relative to the duration of the decay time or the half life time of the thermal neutrons of the earth strata near the bore hole and of the fluid it contains. It also enables the porosity of the stratum or formation to be determined

[en] The invention concerns a nuclear logging process and system specially designed for tubed probes and making it possible to obtain additional data on the location and yield of oil bearing strata. The invention coordinates the study of a neutron characteristic with that of gamma ray spectroscopy to obtain, with a single apparatus, enough information on the various parameters concerning strata enabling a complete and accurate assessment to be made of the oil bearing areas

[en] The apparatus described is employed for logging bore holes by repeated high energy neutron pulses. It includes a sealed logging instrument, a cable with at least one electric conductor and an earth, and a system in the instrument to produce repeated high energy neutron pulses in response to input signals

No abstract available