Complex betwe-gamma analysis is used to determine U and Ra in powder samples of nonequilibrium uranium ores.

Serially produced radiometric and nuclear geophysical spectrometers with rare exceptions contain one or two measuring differential channels, which complicates research and does not provide high labor productivity. As experience of geophysical works shows, radiometric spectrometer should have at least three independent differential channels, nuclear geophysical spectrometer - three-four, and sometimes more channels.

The effective mass attenuation coefficients for gamma radiation of radioactive ores have close values for the integral spectrum measured by a NaI(Tl) scintillator in a standard shield, and for the energy windows used in gamma-spectral logging and ore assaying. ...

The logging gamma-spectrometer developed and tested by us contains three counting and decision-making channels providing continuous recording of gamma-radiation-equivalent concentrations of U, Th and K, and an integral channel. The counting and decision-making channels can be used in the mode of continuous or discrete recording of the average pulse rate in the specified energy windows. The counting and decision-making channels can be used in the mode of continuous or discrete recording of the average pulse rate in the specified energy windows. The spectrometer represents a further development of the apparatus [3], designed only for the determination of U and Th. During its creation, the circuit and design of the prototype underwent a radical revision.

The most promising method of sampling of uranium-thorium ores, which allows separate determination of uranium and thorium, is the gamma-spectral method in the modification of measurements of the differential effect of radiation. The principle of such sampling was considered earlier. ...

The electronic circuit for stabilizing the energy scale is a device that tracks the photopeak of a gamma reference. The basis of the circuit is two adjacent differential channels with the same window width, tuned, respectively, to the left and right branches of the photopeak of the reference source. At the output of both differential channels a comparison circuit and an actuating device are placed. ...

Semiconductor diodes and triodes are widely used in the practice of geophysical instrumentation, which allow a significant increase in efficiency and a reduction in the size and weight of the equipment. However, semiconductor devices, having high performance qualities, at the modern level of production technology are characterized by a scatter of parameters. Therefore, when designing critical circuits of equipment it is necessary to select diodes and especially triodes according to their electrical properties. The analysis of their output characteristics gives the most complete idea of the amplifying properties of transistors. Since the process of taking characteristics point by point is labor‑intensive, there are devices that allow visual observation of the output characteristics of transistors on the oscilloscope screen. Such devices are made in the USSR and abroad in various modifications depending on the range of solved tasks and the required accuracy of observations. Relatively universal units have a complex electronic circuit, simpler ones, as a rule, provide the possibility of only qualitative assessment of amplifying properties of transistors ...