Analysis of the spatial-energy distribution of neutrons in the vicinity of formation boundaries: Neutron log examples.

We present cases of so-called artifacts observed in the response of neutron detectors in the vicinity of formation boundaries (e.g., in neutron logging for geophysical prospecting).

Amplitude degradation of thin layer in neutron logging.

The paper presents an analysis and discussion of the problem of underestimation of neutron signal amplitude in profiling of the thin-layers rock media. The corresponding neutron profiles were modeled using the Monte Carlo method, and the formalism of the general neutron parameter GNP was used to analyze the results. We show that the degradation of the thin layer signal amplitude depends on the layer thickness, and on the difference in the neutron properties of the layer and its surrounding medium.

EXPERIMENTAL AND MONTE CARLO INVESTIGATIONS OF BCF-12 SMALL‑AREA PLASTIC SCINTILLATION DETECTORS FOR NEUTRON PINHOLE CAMERA.

Plastic organic scintillators such as the blue-emitting BCF-12 are versatile and inexpensive tools. Recently, BCF-12 scintillators have been foreseen for investigation of the spatial distribution of neutrons emitted from dense magnetized plasma. For this purpose, small-area (5 mm × 5 mm) detectors based on BCF-12 scintillation rods and Hamamatsu photomultiplier tubes were designed and constructed at the Institute of Nuclear Physics.

Numerical modeling of the gamma-gamma density tool responses in horizontal wells with an axial asymmetry.

A signal of a spectrometric gamma-gamma density tool in specific borehole conditions has been numerically calculated. Transport of gamma rays, from a point (137)Cs gamma source situated in a borehole tool, through rock media to detectors, has been simulated using a Monte Carlo code. The influence of heterogeneity of the rock medium surrounding the borehole on the signal of the detectors has been examined.

Numerical estimation of real and apparent integral neutron parameters used in nuclear borehole geophysics.

The semi-empirical method of neutron logging tool calibration developed by Prof. J.A.