US 6,587,814 B1 · Method and apparatus for improving resolution in spectrometers processing output steps from non-ideal signal sources

Abstract

A method and apparatus for processing step-like output signals generated by non-ideal, nominally single-pole (“N-1P”) devices responding to possibly time-varying, pulse-like input signals of finite duration, wherein the goal is to recover the integrated areas of the input signals. Particular applications include processing step-like signals generated by detector systems in response to absorbed radiation or particles and, more particularly, to digitally processing such step-like signals in high resolution, high rate gamma ray (γ-ray) spectrometers with resistive feedback preamplifiers connected to large volume germanium detectors. Superconducting bolometers can be similarly treated. The method comprises attaching a set of one or more filters to the device's (e.g., preamplifier's) output, capturing a correlated multiple output sample from the filter set in response to a detected event, and forming a weighted sum of the sample values to accurately recover the total area (e.g., charge) of the detected event.

Claims62

Dependent claims

A method for determining the integrated area QgT of a pulse-like input signal by measuring a step-like output signal provided by a nominally single-pole (N-1P) device in response to said pulse-like input signal, the method comprising:

applying a filter set having one or more filters to said N-1P device output;
detecting the presence of a step-like feature in said output signal;
in response to detecting said feature, capturing a set of correlated multiple output sample values (the area cMOS) from one or more filters in said filter set;
and
forming a weighted sum of the sample values in said area cMOS to determine said integrated area QgT (the determined area) of said input signal;
wherein the weights in said sum (the area weights) are selected to compensate said determined area for errors arising either from the time structure of said pulse-like input, or from deviations in the N-1P device's response from an ideal single-pole response, or from both.

3 more elements

Apparatus for measuring a step-like output signal from a nominally single-pole device (N-1P device) in response to a pulse-like input signal to determine the integrated area QgT of said pulse-like input signal, the apparatus comprising:

a set of one or more filters applied to the N-1P device output (the area filter set);
circuitry that detects the presence of a step-like signal in said output signal;
circuitry that captures a correlated multiple output sample (the area cMOS) from said area filter set in response to said detection event;
and
circuitry that forms a weighted sum of the values in said area cMOS to determine said integrated area QgT (the determined area) of said pulse-like input signal;
wherein the weights in said sum (the area weights) are selected to compensate said area determination for errors arising either from the time structure of said pulse-like input signal, or from deviations in the N-1P device's response from an ideal single pole response, or from both.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for improving resolution in spectrometers processing output steps from non-ideal signal sources

Life of this patent

Method and apparatus for improving resolution in spectrometers processing output steps from non-ideal signal sources

Life of this patent

Abstract

Claims62