A Method of Shortening Luminescence Decay Time of Csi(na) Crystal Excited by X and Gamma Rays

Abstract

The invention belongs to the field of nuclear radiation detection, and relates to a method of shortening the luminescence decay time of CsI(Na) crystals to X rays and gamma rays. According to the method, crystals with a micrometer or nanometer magnitude structure are prepared from the CsI(Na) bulk crystals by utilization of a high-energy ball mill and a high-speed air-flow crushing technology. The luminescence decay time to the X rays and the gamma rays is reduced by changing the granularity structure of CsI(Na), allowing that the luminescence decay time 650 ns when the crystals are in a bulk structure reduces to 25 ns when the crystals are in a micrometer structure, thus developing a new technical route for short-pulsed radiation field detection and providing a new detection material for developing ultrafast detectors. The method has simple technology, simple operation, good stability and good reproducibility.

Description

technical field [0001] The invention belongs to the field of nuclear radiation detection, and relates to a method for shortening the decay time of CsI(Na) crystals to X and gamma ray luminescence, and a preparation method for fast pulse radiation detection materials. Background technique [0002] Cesium iodide crystal is a widely used alkali metal halide scintillator. , although the main components are the same, and the physical properties such as density are the same, but their scintillation properties are very different. Pure CsI crystals have a short luminous time (3.5ns) and low luminous efficiency (4-6%NaI(Tl)). The incorporation of sodium activator greatly improves the luminous efficiency of the crystal, and the main component of luminescence is shifted from 310nm to 420nm, which is more conducive to the coupling of emitted light and photomultiplier tube. It is widely used in nuclear radiation imaging, nuclear medicine, space detection and other fields. In particula...

AI Technical Summary

Problems solved by technology

However, the incorporation of sodium activator slows down the luminescence decay time of the crystal from 3.5 ns to 650 ns, which fundamentally limits its application in the rapid detection of pulsed radiation fields and high-energy resolution nuclear radiation imaging.

[0003] At present, the research on the luminescence decay time characteristics of CsI(Na) crystals excited by X and γ-rays mainly focuses on changing the doping concentration of sodium activator, lattice defects, etc. Luminous decay time, but the change of luminous decay time is limited within 10%

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