| 摘要 |
A generalized computer-based system and method for acquisition of nuclear well logging data, including downhole generation of spectral information. A downhole instrument traverses a borehole introducing high energy neutrons into the formation at prescribed depths. Resultant gamma rays are detected and converted into pulses which are amplified and conditioned. For acquiring temporal spectral data, a multi-channel scale section is provided which includes a channel number generator which produces a numerical sequence of memory address codes corresponding to a sequence of adjacent time windows. Each code uniquely defines a start time, whereby the windows collectively comprise the time interval of the desired spectrum. Each time a gamma ray pulse is detected, the memory address generated at that time addresses a corresponding memory location and increments the count value resident therein. At the conclusion of the time spectrum interval of interest, the memory locations may be interrogated by the CPU and the resultant spectral data analyzed, transmitted to the surface, or presented visually as a gamma ray emission count versus time plot.
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