A fully automatic device and method for measuring the helium diffusion coefficient of reactor materials

Abstract

The invention provides full-automatic equipment and method for testing the helium diffusion coefficient of a reactor material. The equipment comprises a gas source control valve, a mass flow controller, a flow control valve, a low-vacuum-side vacuum gauge, a gas discharging control valve, a data acquisition card, a test pond control valve, a sample test pond, a sample to be tested, a high-vacuum-side vacuum gauge, a vacuum pump, a vacuum pump control valve, a helium detector, a computer, a helium gas source, a relay and pipelines; a test system comprises a data acquisition card and a computer; the computer is used for receiving, storing and analyzing data of the low-vacuum-side vacuum gauge, the high-vacuum-side vacuum gauge, the mass flow controller and the helium detector, and performing the process flow control on a system through controlling parts, so as to finally realize the automatic testing and result outputting. According to the equipment and the test method, the helium diffusion coefficient of the reactor material can be automatically tested and the problems of complexity in operation and poor test result repeatability in conventional test equipment are solved.

Description

technical field [0001] The invention relates to a fully automatic device and method for measuring the helium diffusion coefficient of a material, in particular to a fully automatic device and a method for measuring the helium diffusion coefficient of a reactor material. Background technique [0002] The requirement for materials (first wall graphite, carbon-carbon and silicon carbide composites) in fusion reactors is that their helium diffusion coefficients be as low as possible. In a fusion reactor, if helium permeates through the material and enters the plasma, the fusion fuel will be diluted, and the loss of radiation will reduce the temperature of the plasma, which will seriously affect the performance of the reactor, so the diffusion of helium (diffusion refers to Under the effect of concentration gradient of helium, a physical process in which helium molecules migrate freely from the high concentration area through various media to the low concentration area to achieve...

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Problems solved by technology

[0003] The half-time method is to evacuate the permeated gas, then expose one side of the material in the component to the gas, and then adjust to the equal pressure state to reach the equilibrium state, and obtain the time required to reach half the time of the permeation equilibrium state, and then pass this The diffusion coefficient is obtained from the value, which has the advantage of high precision, but the disadvantage is that the test time is too long, and it is not easy to balance due to the interference of external factors such as temperature; the prediction method is the Pasternak solution corresponding to the Fick curve. This method is more convenient to predict, and the time is shorter than that of the half-time method. It comes quickly, but for materials with low diffusion coefficients, the interference of sensors and the environment will make the prediction method less accurate; the time-lag method is a variable pressure measurement method, also known as the "high vacuum method". It is commonly used in measurement. This method refers to calculating the diffusion coefficient by measuring the "lag time" when reaching an equilibrium state under high vacuum conditions, that is, when there is almost no test gas on one side. Its advantage is that the test time is short, so The required variables are few, and the disadvantage is that the requirements for the system and sensors are high, and the data needs to be monitored in real time. The error of the data can easily affect the final test results, and the test accuracy cannot be guaranteed.

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