Multi-parameter test and calibration system and method for spectrometer based on nanosecond light source

Patent metadata

Field	Value
Publication number	US-12031865-B2
Application number	US-202217724944-A
Country	US
Kind code	B2
Filing date	Apr 20, 2022
Priority date	Jul 12, 2021
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

The present disclosure provides a multi-parameter calibration system for a spectrometer based on a nanosecond light source, including a main channel for outputting nuclear pulse signals, and a coincidence channel for outputting the nuclear pulse signals. Each channel uses current nuclear pulse signals to drive a light-emitting diode (LED) to emit nuclear pulse optical signals, and a simulated scintillator is irradiated to emit nanosecond nuclear pulse optical signals. The present disclosure can respectively test and calibrate multiple parameter performance indexes of the spectrometer throughput baseline restoration spectrometer. The stability of the spectrometer is tested and calibrated through output of certain regular nuclear pulse signals.

First claim

What is claimed is:

1. A multi-parameter test and calibration system for a spectrometer based on a nanosecond light source, comprising an upper computer, a ZYNQ system-on-chip (SoC) processor, a double data rate 3 (DDR3), an embedded multimedia card (EMMC), a power supply unit, a main channel for outputting nuclear pulse signals, and a coincidence channel for outputting the nuclear pulse signals, wherein the ZYNQ SoC processor comprises an advanced RISC machine (ARM) unit and a field programmable gate array (FPGA) unit, the upper computer is connected to the ZYNQ SoC processor through a network port, the DDR3 and the EMMC are connected to the ZYNQ SoC processor respectively, the ZYNQ SoC processor is connected to the main channel for outputting the nuclear pulse signals and the coincidence channel for outputting the nuclear pulse signals respectively, and the main channel for outputting the nuclear pulse signals is connected to a main channel of the spectrometer and the coincidence channel for outputting the nuclear pulse signals is connected to a coincidence channel of the spectrometer, wherein
the main channel for outputting the nuclear pulse signals comprises a digital-to-analog converter (DAC) chip, a differential to single-ended unit, a light-emitting diode (LED), an optical filter, a photomultiplier tube (PMT), a preamplifier, and a to-be-tested spectrometer system; and the DAC is connected to the FPGA unit of the ZYNQ SoC processor, input of the differential to single-ended unit is connected to an output pin of the DAC, output of the differential to single-ended unit is connected to the LED, the optical filter is attached between the PMT and the LED, an output terminal of the PMT is connected to the preamplifier, and the preamplifier is connected to a main channel of the to-be-tested spectrometer system,
the coincidence channel for outputting the nuclear pulse signals comprises a DAC chip, a differential to single-ended unit, an LED, an optical filter, a PMT, a preamplifier, and a to-be-tested spectrometer system; and the DAC is connected to the FPGA unit of the ZYNQ SoC processor, input of the differential to single-ended unit is connected to an output pin of the DAC, output of the differential to single-ended unit is connected to the LED, the optical filter is attached between the PMT and the LED, an output terminal of the PMT is connected to the preamplifier, and the preamplifier is connected to a Compton scattering anti-coincidence measurement channel of the to-be-tested spectrometer system.

2. The multi-parameter test and calibration system for a spectrometer based on a nanosecond light source according to claim 1 , wherein the ARM unit is connected to the FPGA unit through an AXI bus, and the EMMC is connected to the ARM unit of the ZYNQ SoC processor through a general input-output (IO) port.

3. A test and calibration method for the multi-parameter test and calibration system for a spectrometer based on a nanosecond light source according to claim 2 , comprising the following steps:
(1) obtaining, by the upper computer, an energy spectrum curve 1 required for output of the main channel and an energy spectrum curve 2 required for output of the coincidence channel using a large amount of measured data and Monte Carlo simulation according to functions selected by a user;
(2) when the ZYNQ SoC processor obtains the energy spectrum curve 1 , inverting the energy spectrum curve 1 into a series of nuclear pulse signals, or directly outputting nuclear pulse signals containing one or more rise times and fall times according to different functions selected by the user, and outputting the nuclear pulse signals at random or fixed time intervals in the main channel after corresponding processing according to different functions;
(3) calculating, by the ZYNQ SoC processor, correlation between the nuclear pulse signals output from the coincidence channel and the nuclear pulse signals of the main channel according to the functions and parameters set by the user;
(4) when the ZYNQ SoC processor obtains the energy spectrum curve 2 , inverting the energy spectrum curve 2 into a series of nuclear pulse signals, and outputting the nuclear pulse signals in the coincidence channel according to the correlation between the nuclear pulse signals of the main channel and the nuclear pulse signals of the coincidence channel; and
(5) after the nuclear pulse signals output from each channel are acquired by the to-be-tested spectrometer, comparing acquired information with data generated according to the parameters set by the user, so as to test and calibrate multiple parameters of the spectrometer.

4. The test and calibration method according to claim 3 , wherein a method for outputting the nuclear pulse signals from the main channel and the coincidence channel is as follows: converting, by a DAC, digital signals into analog nuclear pulse signals, converting, by a differential to single-ended unit, differential signals into single-ended nuclear pulse signals, converting, by an LED, nuclear pulse current signals into optical signals, converting, by a PMT, the optical signals into electrical signals, conditioning and outputting, by a preamplifier, PMT anode signals, and receiving, by a to-be-tested spectrometer system, the nuclear pulse signals of the two channels and comparing the nuclear pulse signals with the data generated according to the parameters set by the user, so as to test and calibrate multiple parameters of the spectrometer.

5. The test and calibration method according to claim 4 , wherein in step (1), the functions selected by the user comprise the calibration and test of multiple parameters such as the coincidence and anti-coincidence performance test and calibration of the spectrometer, the broadening test of a spectral line after spectrometer detection, the resolution test and calibration of the spectrometer, the distortion degree of the spectral line, the test and calibration of the throughput and the counting rate of the spectrometer, the dead time test and calibration of the spectrometer, the baseline restoration capability and direct current (DC) offset accuracy of the spectrometer, the energy detection range of the spectrometer, the spectrum stabilization performance test and calibration of the spectrometer, the signal-to-noise ratio improvement capability of the spectrometer, the working performance test of various preamplifiers, the pulse shape discrimination capability, the accuracy test and calibration of the rise time and fall time of extracted nuclear pulse signals, the effect test of a shaping algorithm, the analysis of signal acquisition accuracy of the spectrometer, and the stability test of the spectrometer.

6. The test and calibration method according to claim 3 , wherein in step (2), the corresponding processing is as follows: when the baseline restoration capability of the spectrometer is selected to be tested, coupling a DC offset to the nuclear pulse signal; and when the signal-to-noise ratio improvement capability test function of the spectrometer is selected, coupling high-frequency noise to the nuclear pulse signal, wherein no processing is done when other functions are selected.

7. The multi-parameter test and calibration system for a spectrometer based on a nanosecond light source according to claim 1 , wherein the power supply unit is connected to the upper computer, the ZYNQ SoC processor, the DDR3, the EMMC, the main channel for outputting the nuclear pulse signals, and the coincidence channel for outputting the nuclear pulse signals respectively.

8. A test and calibration method for the multi-parameter test and calibration system for a spectrometer based on a nanosecond light source according to claim 7 , comprising the following steps:

Assignees

• Univ Chengdu Technology

Inventors

• Zeng Guoqiang
• Gu Min
• Li Qing
• Hu Chuanhao
• Yang Xiaofeng
• Hu Shimin
• Yang Jian

Classifications

• G01J3/28

  Investigating the spectrum (using colour filters G01J3/51) · CPC title

• G01J3/0297 Primary

  Constructional arrangements for removing other types of optical noise or for performing calibration · CPC title

• G01T7/005 Primary

  calibration techniques (stabilization of spectrometer G01T1/40) · CPC title