Two-dimensional positron annihilation angle correlation measurement device and method

Abstract

The invention, which belongs to the technical field of nuclear detection, relates to a two-dimensional positron annihilation angle correlation measurement device and method, thereby solving problems that an existing measurement device is large in counting loss, complex in operation and difficult to popularize and apply. According to the device, a first fixed detector and a second fixed detector are symmetrically arranged on the two sides of a sample in parallel respectively; a plurality of first square detection units of the first fixed detector and a plurality of second square detection unitsof the second fixed detector are respectively used for detecting incident position information of first gamma photons and second gamma photons which are generated by annihilation of electrons and positron in the sample and are propagated along the reverse direction; and a coincidence system is used for collecting incident position information of the first gamma photons and the second gamma photons within coincidence time, obtaining a corresponding three-dimensional submergence angle in combination with the position information of the sample, and further obtaining a two-dimensional positron annihilation angle correlation spectrum. The counting rate and the measurement precision are improved, the operation is simplified, and the applicability is high.

Description

technical field [0001] The invention relates to the technical field of nuclear detection, in particular to a two-dimensional positron annihilation angle correlation measurement device and method. Background technique [0002] At first, the Positron Annihilation Angle Correlation (ACAR) was mainly used to study the physical process of positron and electron annihilation. In the 1930s, O. Klemperer, through his angle correlation experiments, revealed that positron annihilation mainly emits two gamma photons in opposite directions. Twenty years later, it was realized that information about the electronic structure of solids could be obtained by measuring deviations from the collinearity of annihilation radiation. During this period, one-dimensional angular correlating devices with long slit structures were mainly used. Another 20 years later, due to the development and use of two-dimensional gamma cameras and multi-wire proportional chambers, the first two-dimensional angle co...

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Problems solved by technology

[0005] In view of the above analysis, the present invention aims to provide a two-dimensional positron annihilation angle correlative measurement device and method to solve the p

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