Fission chamber based on Micromegas

Abstract

The invention discloses a fission chamber based on Micromegas. The fission chamber comprises a Micromega detector, wherein the Micromega detector is provided with a metal shell, and a drift electrode, a Micromega microgrid and a collecting electrode which are arranged in the metal shell; the Micromega microgrid is arranged between the drift electrode and the collecting electrode; the collecting electrode is electrically connected with a pulse signal acquisition circuit; a drift region is formed between the Micromega microgrid and the drift electrode, and a collection region is formed betweenthe Micromega microgrid and the collection electrode; a gas chamber is defined by the metal shell, the drift electrode and the collecting electrode, and flowing ionized gas is arranged in the gas chamber; a plurality of aluminum plates are also arranged in the drift region; each aluminum plate is vertical to the drift electrode, and one side of each aluminum plate is fixedly connected with the drift electrode; and uranium-235 layers are arranged on the two side faces of each aluminum plate. The fission chamber is high in detection efficiency, high in sensitivity and high in counting rate range; and the fission chamber has better anti-interference capability and stronger n / gamma discrimination capability, and is especially suitable for real-time monitoring of the neutron fluence rate of a reactor and other strong electromagnetic interference and strong gamma radiation field environments.

Description

technical field [0001] The invention belongs to the field of fission chambers, in particular to a fission chamber based on Micromegas. Background technique [0002] From the start-up of the reactor to full power operation, the dynamic variation range of its nuclear power will reach 10 orders of magnitude, and the corresponding neutron fluence rate variation range will reach 11 orders of magnitude (10 0 ~10 11 n / cm 2 .s), for subcriticality, control and safety purposes, the neutron flux rate in the core and its changes must be monitored during all phases of reactor operation, on the other hand, the gamma intensity around the reactor is very high, therefore, for reactor The neutron detector for neutron fluence rate monitoring needs to meet two conditions, one is that the detector has a wide measuring range, and the other is that the detector has a strong n / γ discrimination ability. [0003] Due to the limited range of general neutron detectors, it is difficult to cover such...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a Micromegas-based fission chamber with high sensitivity for the current fission chamber monitoring reactors with low thermal neutron sensitivity, small dynamic range of counting rate, and cumbersome switching of monitoring modes during the process from start-up to full power of the current fission chamber. , with a high counting rate range, in order to achieve full coverage of neutron fluence rate monitoring from physical startup to full power operation of the reactor in single pulse mode

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