Method for predicting experiment result of screen-grid ionization chamber for measuring neutron-induced nuclear reaction

Abstract

The invention discloses a method for predicting an experiment result of a screen-grid ionization chamber for measuring a neutron-induced nuclear reaction. The method comprises the steps of obtaining the energy of charged particles generated by a to-be-measured reaction and other possible interference reactions, the emergent direction information, and the energy loss and range information of the charged particles through a Monte Carlo simulation method, and quantitatively obtaining the energy-counting relationship of the emergent particles of the reaction to be measured. By changing simulation conditions such as sample thickness, working gas type in an ionization chamber, air pressure, neutron energy and the like, a corresponding energy-counting relationship for reflecting the emergent charged particles is obtained, so that an experiment result is more visually obtained through the relationship, and various experiment conditions are optimized. The method can guide the formulation of an ionization chamber nuclear reaction measurement experiment plan, and can determine the measurement efficiency.

Description

technical field [0001] The invention belongs to the field of radiation detection, and in particular relates to a method for predicting experimental results of neutron-induced reactions measured in an ionization chamber. Background technique [0002] Screen ionization chamber (hereinafter referred to as ionization chamber) is used to measure fast neutrons (neutron energy E n >1MeV) induced light charged particle exit nuclear reaction, such as (n,α) reaction common detector. The inside of the ionization chamber is filled with working gas (generally more than 90% inert gas + less than 10% polyatomic gas, such as CO 2 or H 2 ), and mainly consists of a cathode and two anodes, two shielding poles and two grids, a total of 7 parallel plates, forming a structure of shielding pole-anode-grid-cathode-grid-anode-shielding pole , the main concern in the experimental measurement is the cathode and the anode, so the cathode and the anode are mainly discussed in this specification, ...

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Problems solved by technology

The particles produced by these interference reactions will all contribute to the energy spectrum finally measured by the ionization chamber (that is, the energy-corresponding count relationship measured by the anode and cathode of the ionization chamber) due to the deposition of energy in the ionization chamber and being detected, while the ionization The energy spectrum measured in the chamber is the sum of the contributions of the reaction to be measured and all other interference reactions, so if the energy spectra of the interference reaction and the nuclear reaction to be measured overlap, it may not be possible to distinguish them, so that the energy spectrum obtained by the experimental measurement cannot be found at all. The particle of the nuclear reaction to be tested, which finally caused the experiment to fail

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