GB/T 46609-2025 Test method for neutron-gamma ray detection performance of scintillation crystals English, Anglais, Englisch, Inglés, えいご
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ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB/T 46609-2025
Test method for neutron-gamma ray detection performance of scintillation crystals
闪烁晶体的中子-伽马射线探测性能测试方法
Issue date: 2025-10-31 Implementation date: 2026-05-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Test Principle
5 Test Requirements and Test System
6 Test Method
1 Scope
This document describes the test methods for evaluating the neutron-gamma ray detection performance of scintillation crystals.
This document applies to testing the neutron-gamma ray detection performance of scintillation crystals. Other scintillation materials such as scintillation ceramics, scintillation glass, and composite scintillators may refer to this document for implementation.
2 Normative References
The following documents contain provisions that, through normative reference in this text, constitute essential provisions of this document. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 4075-2009 Sealed radioactive sources—General requirements and classification
GB/T 4960.6-2008 Terminology of nuclear science and technology—Part 6: Nuclear instrumentation
GB/T 13181-2024 Methods for measurement of performance of solid scintillators
GB 18871-2002 Basic standards for protection against ionizing radiation and for the safety of radiation sources
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
optical reflector (of a scintillator)
A layer covering the surface of a scintillator (or light guide) to effectively reflect the light emitted omnidirectionally within the scintillator (or light guide) towards the exit direction.
[SOURCE: GB/T 4960.6-2008, 2.3.11]
3.2
scintillation detector
A nuclear radiation detector consisting of a scintillator and a photosensor. The scintillator is typically optically coupled to the photosensor through optical coupling material or a light guide.
[SOURCE: GB/T 4960.6-2008, 2.3.41, modified]
3.3
optical coupling material
Material applied between the optical window of a scintillator and the entrance window of a photosensor (or between the scintillator optical window and a light guide, and between the light guide and the photosensor entrance window) to efficiently transmit the light generated by the scintillator to the photosensor.
[SOURCE: GB/T 4960.6-2008, 2.3.40, modified]
3.4
light guide
An optical component used to transmit scintillation light from the scintillator to the photosensor, placed between the scintillator and the photosensor.
[SOURCE: GB/T 4960.6-2008, 2.3.27, modified]
3.5
sealed source
Radioactive material that is permanently sealed in a capsule or bonded within a solid material. The capsule or bonding material is strong enough to maintain the seal under the conditions of use and wear for which the source is designed.
[SOURCE: GB 4075-2009, 3.11]
3.6
full-energy peak
The spectral peak in the energy spectrum measured by a radiation detector, corresponding to the full energy deposition of monoenergetic radiation.
3.7
gamma equivalent energy (of a neutron); GEE
The energy corresponding to the neutron peak as measured using a gamma energy scale.
3.8
pulse shape discrimination technique; PSD
A technique for particle discrimination based on differences in the scintillation pulse waveforms.
3.9
figure of merit (of pulse shape discrimination); FOM
An index for evaluating the effectiveness of pulse shape discrimination. A higher FOM value indicates better discrimination performance.
4 Test Principle
The test principle for determining the neutron equivalent energy based on the detector's response is as follows: If a neutron of a certain energy and a gamma ray of a certain energy produce the same signal response (e.g., pulse height or integrated charge) in the detector, then that gamma ray energy is the equivalent energy of the neutron.
The core principle of neutron-gamma ray pulse shape discrimination is a technique that utilizes differences in the pulse waveform characteristics (such as rise time, decay time, amplitude ratio) generated by neutrons and gamma rays in the detector to discriminate between them. Figure 1 illustrates the contrast between neutron and gamma pulse waveforms.
5 Test Requirements and Test System
5.1 General Requirements for Testing
5.1.1 Environmental Requirements
The test environment shall meet the following requirements:
a)Temperature: (25 ± 2) °C;
b) Relative humidity not exceeding 50%;
c) No significant vibration, airflow, smoke, dust, or electromagnetic interference.
5.1.2 Safety Requirements
Radiation protection measures shall be implemented in accordance with the provisions of GB 18871-2002.
5.2 Sample
Samples shall meet the following requirements:
a)The test sample shall be coated with an optical reflector layer. If the sample is hygroscopic, moisture-proof measures shall also be taken.
b)b) To ensure detection efficiency, it is recommended that the sample size be no smaller than 5 mm × 5 mm × 5 mm or ϕ5 mm × 5 mm.
5.3 Test System
5.3.1 Composition of the Test System
The test system mainly consists of:
