Flicker-wavelength-shifting optical fiber and fast neutron conversion screen

Abstract

The invention discloses a flicker-wavelength-shifting optical fiber and a fast neutron conversion screen, belonging to the field of fast neutron imaging. The optical fiber disclosed by the invention sequentially comprises a core layer, a covering layer and a reflection film from inside to outside, wherein the core layer is a wavelength-shifting optical fiber, the covering layer is a hydrogen-containing organic matter doped with fluorescent powder, and the wavelength-shifting optical fiber of the core layer can absorb light emitted by the fluorescent powder of the covering layer and emit secondary photons. In the fast neutron conversion screen disclosed by the invention, a screen surface is formed by a plurality of sections of optical fiber end faces obtained by arraying optical fibers with equal lengths. Compared with the prior art, the invention ensures that the thickness of the conversion screen can be greatly improved, fast neutron detection efficiency can be increased by over 10 times compared with the common ZnS screen; and the reflection film on the outer layer can enhance the light-emitting strength of the conversion screen and effectively increase the resolution rate of the conversion screen. The invention has a matured generation process and can realize commercialized volume production.

Description

technical field [0001] The invention belongs to the field of fast neutron imaging, in particular to a scintillation-wave-shifting optical fiber for fast neutron imaging based on wave-shifting (fluorescence) optical fiber and a reflective film for high-performance fast neutron detection-wave-shifting optical fiber and based on scintillation-wave-shifting optical fiber Fabricated fast neutron transition screen. Background technique [0002] Neutron imaging is a new type of non-destructive detection technology. Since neutrons are not charged and have strong penetrability to matter, they can be used to measure the internal characteristics and information of objects or materials with large volumes and high densities. At the same time, neutrons have a large reaction cross-section with some light elements such as H, Li, and Be, which can make up for the gaps that are not easy to detect on these light elements by ordinary detection methods. At present, neutron imaging has been wid...

AI Technical Summary

Problems solved by technology

However, due to the opaqueness of the inorganic scintillator itself, the effective thickness of the ordinary ZnS screen is thin and the detection efficiency is low.

Adding wave-shifting (domestic called fluorescence: the same below) optical fiber to the scintillation screen can greatly increase the effective thickness of the scintillation screen, but the increase in thickness also causes a decrease in resolution

On the other hand, fast neutron scintillation screens have no standard size and are not suitable for mass production with special equipment. It is difficult to evenly distribute wave-shifting fibers in the scintillation screen without special equipment, and designing special equipment will greatly increase the cost. Currently, there is no Proper process for making

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