Neutron detector based on fission-electron collection principle

Abstract

The invention discloses a neutron detector based on the fission-electron collection principle. The neutron detector comprises a shell, a collecting electrode, a sensitive electrode and an external magnetic field, wherein the sensitive electrode is made from uranium alloy. Neutrons penetrate through the shell through a radiation channel and are emitted into the sensitive electrode, a uranium element in the sensitive electrode generates a fission reaction to form fission fragments, parts of electrons generated by the fission fragments escape from the surface of the sensitive electrode, the motion trails of the electrons deflect under the action of the external magnetic field, and the collecting electrode collects the deflected electrons. According to the neutron detector based on the fission-electron collection principle, the unstable problem of a uranium plating film of the sensitive electrode and bad influences of the fission fragments on measurement can be avoided, neutron signals are separated out of gamma backgrounds, and the neutron detector can be used for neutron measurement in a neutron-gamma mixed radiation field.

Description

technical field [0001] The invention belongs to the field of radiation measurement, in particular to a neutron detector based on the principle of fission-electron collection. Background technique [0002] The amperometric detector used for real-time measurement of the number of neutrons will output current for both neutrons and gamma. When neutrons are measured in the neutron-gamma mixed radiation field, the current generated by gamma forms the background, which needs to be reduced or eliminated. influence of the signal. [0003] The journal article Radiation Measurements 73 (2015) 46-50 discloses an amperometric "fission-electron collection" neutron detector comprising a housing, a collecting electrode, a U3O8 coating and a coated electrode. The collecting electrode and the coating electrode are circular aluminum metal sheets, and the U3O8 coating is attached to the coating electrode in the form of coating. The housing is cylindrical to maintain the vacuum environment and...

AI Technical Summary

Problems solved by technology

Since the adhesion of the coating decreases with the increase of the thickness, the thicker the coating is, the easier it is to fall off. Increasing the thickness of the coating to improve the sensitivity of the detector is limited.

In addition, gamma rays in the mixed field eject electrons from the collecting electrodes, and the resulting signal forms a background that interferes with neutron measurements

[0005] In the prior art, the collecting electrode of the current-type "fission-electron collection" neutron detector is directly facing the coating, and the fission fragments flying from the surface of the coating will cause adverse effects

The fission fragments are positively charged, and being received by the collecting electrode will cause the signal output to drop, and the fission fragments will also eject electrons from the collecting electrode, causing a further drop in signal output, which in turn affects the neutron measurement

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