METHOD FOR STABILIZING A SCINTILLATION DETECTOR

摘要

A method for calibrating a logging tool that is exposed to an external energy spectrum, comprising the steps of: (a) providing a stabilization source that emits a stabilization signal having a known energy; (b) providing a receiver that receives a total spectrum that comprises the sum of the external energy spectrum and the received stabilization signal; (c) discerning the stabilization signal in the total spectrum by the steps of: calculating the centroid of the area under the total spectrum; adjusting the gain of the tool on the basis of the calculated centroid; dividing a portion of the spectrum that includes the known energy level of the stabilization peak into a number of windows of equal width, with an equal number of windows on either side of the stabilization peak energy; using the count rates in each of the windows to calculate a value D n that is proportional to the n th derivative of the spectrum at the stabilization peak energy; and adjusting the gain of the tool on the basis of the value of D n