X-ray spectrometer and sample analyzer

Patent metadata

Field	Value
Publication number	US-9188552-B2
Application number	US-201414225718-A
Country	US
Kind code	B2
Filing date	Mar 26, 2014
Priority date	Mar 26, 2014
Publication date	Nov 17, 2015
Grant date	Nov 17, 2015

Abstract

An X-ray spectrometer ( 100 ) capable of reducing the effects of noises includes: an X-ray detector ( 110 ) outputting a staircase waveform (S 110 ); a first differential filter ( 120 ) converting the staircase waveform (S 110 ) into a first pulsed signal (S 120 ); an event detection portion ( 140 ) detecting whether the first pulsed signal (S 120 ) has exceeded a threshold value; a noise event detection portion ( 150 ) determining whether the first pulsed signal (S 120 ) in excess of the threshold value is shorter than a given time; a second differential filter ( 160 ) converting the staircase waveform (S 110 ) into a second pulsed signal (S 160 ) having peaks whose heights correspond to the heights of the steps of the staircase waveform; a maximum value detection portion ( 170 ) detecting pulsed signal (S 160 ) if the first pulsed signal (S 120 ) exceeds a threshold value; and a decision portion ( 180 ) making a decision based on the noise event detection portion ( 150 ).

First claim

The invention claimed is:

1. An X-ray spectrometer comprising:
an X-ray detector for detecting X-rays and outputting a staircase waveform having steps whose heights correspond to energy levels of the X-rays;
a first differential filter having a time constant and operative to convert the staircase waveform into a first pulsed signal having peaks whose heights correspond to the heights of the steps;
an event detection portion for making a decision as to whether the first pulsed signal has exceeded a threshold value;
a noise event detection portion for making a decision as to whether a period during which the first pulsed signal is in excess of the threshold value is shorter than a given time;
a second differential filter having a time constant longer than the time constant of the first differential filter and operative to convert the staircase waveform into a second pulsed signal having peaks whose heights correspond to the heights of the steps;
a maximum value detection portion which, if the first pulsed signal is judged to be in excess of the threshold value, starts to detect a maximum value of the second pulsed signal; and
a decision portion for making a decision as to whether information about the maximum value is output, based on the decision made by the noise event detection portion.

2. An X-ray spectrometer comprising:
an X-ray detector for detecting X-rays and outputting a staircase waveform having steps whose heights correspond to energy levels of the X-rays;
a first differential filter having a time constant and operative to convert the staircase waveform into a first pulsed signal having peaks whose heights correspond to the heights of the steps;
an event detection portion for making a decision as to whether the first pulsed signal has exceeded a first threshold value;
a noise event detection portion for making a decision as to whether said first pulsed signal is below a second threshold value;
a second differential filter having a time constant longer than the time constant of the first differential filter and operative to convert the staircase waveform into a second pulsed signal having peaks whose heights correspond to the heights of the steps;
a maximum value detection portion which, if the first pulsed signal is judged to be in excess of the first threshold value, starts to detect a maximum value of the second pulsed signal; and
a decision portion for making a decision as to whether information about the maximum value is output, based on the decision made by the noise event detection portion.

3. An X-ray spectrometer as set forth in claim 2 ,
wherein said peaks of the first pulsed signal appear on a positive side of a reference level;
wherein said first threshold value is set on the positive side; and
wherein said second threshold value is set on a negative side of the reference level.

4. A sample analyzer including an X-ray spectrometer as set forth in any one of claims 1 to 3 .

Assignees

• Jeol Ltd

Inventors

• Kinugasa Genki

Classifications

• G01N23/2076 Primary

  for spectrometry, i.e. using an analysing crystal, e.g. for measuring X-ray fluorescence spectrum of a sample with wavelength-dispersion, i.e. WDXFS · CPC title

• G01N23/223

  by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence · CPC title

• G01T1/17

  Circuit arrangements not adapted to a particular type of detector {(pulse-selection circuits H03K, G01R)} · CPC title

• G01T1/247

  Detector read-out circuitry (for processing gain or off-set correction H04N) · CPC title

• H01J2237/24425

  Wavelength-dispersive spectrometer · CPC title