A pulsed gamma ray energy spectrum measurement system and method based on nuclear resonance fluorescence

Abstract

The invention relates to a nuclear resonance fluorescence-based pulse gamma ray energy spectrum measuring system and method. The device comprises lead collimators, a HPGe detector and a specific target sheet; the lead collimators and the specific target sheet are sequentially disposed in the beam direction of pulse gamma rays to be measured; the HPGe detector is located to one side of the pulse gamma rays to be measured; and an included angle between the HPGe detector and the beam direction ranges from 90 degrees to 120 degrees; a plurality of target materials are stacked so as to form the specific target sheet; and the energy level of each target material is within the energy range of the pulse gamma rays to be measured. The method includes the following steps that: 1) a HPGe detector isadopted to detect the number R of photons emitted by the pulse gamma rays to be measured during nuclear resonance fluorescence; 2) photon density is calculated; and 3) and Gaussian fitting is performed on the basis of the photon density, so that the energy spectrum distribution diagram of the pulse gamma rays to be measured is obtained. With the method of the invention adopted, a pulse gamma ray energy spectrum measurement experiment is simple to set, later-stage calculation is simple, and measurement accuracy is high.

Description

technical field [0001] The invention belongs to nuclear radiation energy spectrum measurement technology, in particular to a pulse gamma ray energy spectrum measurement system and method based on nuclear resonance fluorescence. Background technique [0002] When the energy of the incident gamma photon is equal to the energy level difference between the excited state and the ground state of the nucleus, the nucleus will undergo strong resonant absorption, and then be in an excited state. The process of releasing gamma photons of specific energy is nuclear resonance fluorescence (Nuclear Resonance Fluorescence, NRF). Since the nuclear energy level bandwidth is very narrow, the released gamma photon bandwidth is very narrow (ΔE / E=10 -6 ). The response cross section of nuclear resonance fluorescence can be expressed as: [0003] [0004] Among them, E is the incident γ-ray energy; λ is the corresponding wavelength; E r is the resonance energy; Γ is the sum of bandwidths f...

AI Technical Summary

Problems solved by technology

[0010] The attenuation method requires complex spectral analysis methods for later calculations, while the magnetic analysis method usually requires a large magnet, and the experimental setup is more complicated

Images