Large Bi-2212 superconducting coil heat treatment furnace system and pressure control method thereof

Abstract

The invention discloses a large Bi-2212 superconducting coil heat treatment furnace system and a pressure control method of the large Bi2212 superconducting coil heat treatment furnace system. The system comprises a pressure-resistant furnace shell, a pressure-resistant furnace cover, a heat insulation layer, a heating chamber, a uniform-temperature radiation screen, a gas pipeline, a safety device and the like. Heat-treatment high temperature and high pressure system design requirements of a Bi-2212 superconducting coil are met. Due to the design of the uniform-temperature radiation screen ina heat treatment furnace, on one hand, the heat treatment temperature uniformity of the superconducting coil is improved, and on the other hand, the cleanliness of the superconducting coil is ensured. The pressure control method comprises the following stages of gas replacement in a pressure-resistant furnace shell, gas replacement in the uniform-temperature radiation screen, and synchronous pressurization and gas micro-feeding and micro-discharging. The large Bi-2212 superconducting coil heat treatment furnace system and the pressure control method of the large Bi2212 superconducting coil heat treatment furnace system have the advantages that the system adopts intrinsic safety design, the safety, reliability and performance-cost ratio are high. The system is suitable for processing largeBi-2212 superconducting coils with the outer diameters of 0.1-3m and the heights of 0.1-3m. The heat treatment temperature of the superconducting coil can be effectively controlled, the temperature uniformity of the superconducting coil can reach + / -5 DEG C, and the superconducting performance of the Bi-2212 superconducting coil is improved.

Description

technical field [0001] The invention relates to the technical field of heat treatment of large Bi-2212 superconducting coils, in particular to a large Bi-2212 superconducting coil heat treatment furnace system and a pressure control method thereof. Background technique [0002] With the development of technology and research, the requirements for magnetic field strength have also increased, such as large accelerator magnets, fusion device magnets, etc., all need to provide ultra-high background magnetic fields. Low temperature superconductor Nb 3 Sn and NbTi are subject to the upper critical field (Hc 2 ) has been gradually unable to meet the demand. Therefore, high-temperature superconducting materials with high critical fields can meet the needs of future high-field magnet development. [0003] The critical temperature of Bi-2212 high-temperature superconducting material is 85K, and its upper critical magnetic field at 4.2K is 100T. Bi-2212 is currently the only high-t...

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Problems solved by technology

[0010] (3) There is complexity in the equipment and process control in the heat treatment process

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