Focusing device for monochromatic neutron

Abstract

The invention discloses a focusing device for monochromatic neutrons. The device is a vertical focusing device for the monochromatic neutrons used for a neutron diffraction spectrometer, and comprisesa frame, a vertical adjustment driving assembly, and a horizontal swing angle adjusting assembly. The vertical adjustment driving assembly is in an independent design and can independently adjust thevertical angle of a single wafer. The wafer fixing plate in the horizontal swing angle adjusting assembly is a cuboid with one end closed and the other open and can achieve the horizontal swing angleadjustment of the wafer fixing plate. According to the focusing device for the monochromatic neutrons, in the focusing adjustment for the monochromatic neutrons, the single wafer is provided with thefunctions of vertical focusing and horizontal swing adjusting, the beam spots are uniform, the neutron intensity can reach the optimum value, and the divergence of the beam spots caused by the difference between the reflection crystal plane and the surface included angle is effectively reduced, and the radiation dose of a personnel is reduced. The device is used with germanium mosaic crystals andthe neutron diffraction spectrometer, can monochromize the large-size white light neutron beams, focus to the sample position, and form into a concentrated monochromatic neutron beam, so that the intensity and the utilization rate of the neutrons are improved.

Description

technical field [0001] The invention belongs to the technical field of neutron beam monochromation and focusing, and in particular relates to a monochromatic neutron focusing device. Background technique [0002] The neutrons produced by the reactor are white light neutrons with continuous wavelengths. The white light neutrons are reflected by the germanium mosaic crystal. According to Bragg's law, the monoenergetic neutrons of specific wavelengths in the white light neutrons of the reactor can be deflected to meet the needs of neutron diffraction. The neutron intensity at the sample is a key technical index that directly affects the performance of the spectrometer. By using the focusing device to converge the monochromatic neutron beam, the neutron intensity at the sample can be effectively increased. The main function of the focusing device is to change the vertical inclination and horizontal direction of each single crystal, so that the single crystal can reflect neutrons...

AI Technical Summary

Problems solved by technology

[0003] However, the current monochromatic neutron focusing technology still has many shortcomings. The focus adjustment function of the wafer adopts a mechanical linkage method. By pre-setting the rotation ratio of each axis, a single motor is used to control the vertical angle of all wafers.

Since the reflective surface of the wafer is not parallel to the surface, the angle between each wafer and the surface is not consistent, which will cause the neutron beams reflected by each wafer to not completely overlap at the sample, which not only reduces the neutron intensity, but also due to the neutron beam spot area The increase will also have a great impact on the signal-to-noise ratio of the spectrometer. In addition, this method requires more manual operations, and there is greater radiation to the debugger.

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