Dynamic shaping time modification in X-ray detectors
View Patent ↗Methods and apparatus for adapting the shaping time and/or other pulse processing parameters of an x-ray detector ( 114 ) in accordance with the elemental composition of a sample and/or energy resolving requirements. X-rays ( 104 ) are directed from a source ( 102 ) onto a sample ( 110 ) and the radiation ( 108 ) responsively emitted from the sample (e.g., fluoresced radiation characteristic of the sample's elemental composition) and detected by an x-ray detector ( 114 ) that generates pulses representative of the energy and intensity of the incident radiation. Based upon initial analysis of elemental composition, the shaping time and/or other pulse processing parameter (s) are set to optimize count rate subject to constraints of energy resolution in a spectral region of interest.
1. A method for analyzing elemental composition of a sample, the method comprising:
a. irradiating the sample with x-rays;
b. detecting x-rays fluoresced by the sample in response to irradiation, thereby generating detector signal pulses;
c. preamplifying the detector signal pulses;
d. processing the detector signal pulses subject to pulse processing parameters;
e. determining energy resolution requirements based on analysis of sample composition; and
f. setting at least one of the pulse processing parameters on the basis of the determined energy resolution requirements.
2. A method in accordance with claim 1 , wherein the at least one of the pulse processing parameters includes a detector shaping time.
3. An x-ray fluorescence instrument for analyzing elemental composition of a sample, the instrument comprising:
a. a source of x-rays for irradiating the sample;
b. a detector for detecting x-rays fluoresced by the sample in response to irradiation, thereby generating detector signal pulses;
c. a preamplifier for amplifying the detector signal pulses;
d. a signal processor for processing the detector signal pulses;
e. a controller for governing processing parameters; and
f. a signal path between the controller and at least one of the signal processor and the preamplifier, so that a pulse processing parameter can be varied in accordance with composition of the sample.
4. An x-ray fluorescence instrument in accordance with claim 3 , wherein the signal processor includes a digital signal processor.
5. An x-ray fluorescence instrument in accordance with claim 3 , wherein the source of x-rays is an x-ray tube.
6. An x-ray fluorescence instrument in accordance with claim 3 , wherein the pulse processing parameter is a detector shaping time.