method and device for the investigation of bohrloechern with gamma rays from the inelastischen scattering of fast neutrons

摘要

The strata around a well are irradiated with high-energy neutrons; the gamma-rays derived from the inelastic scattering of fast neutrons are measured selectively and their spectral distribution is determined. To facilitate the spectral analysis within the brief neutron pulse, a first measurement is carried out with a pulsed neutron source and a sensor. This alternates with a second measurement with a neutron source with a constant level of emission. The difference between the results of the two measurements indicates the gamma-ray formation by inelastic scattering. The energy discrimination furnishes a spectral analysis and the C/O2 ratio and Si/Ca ratio can be determined.