加速器驱动次临界系统(Accelerator Driven Sub-critical System, ADS)注入器 I 超导磁铁经过2012年模型磁铁（300 mm 长磁铁）阶段后，因加速器物理设计需要，磁铁机械长度缩短到170 mm，截至到2014年共经过了三种结构类型的超导磁铁的研制。2014年7月在哈尔滨工业大学进行短磁铁的低温垂直测试，磁铁的各项性能指标都满足了设计要求，同时也验证了失超探测和磁场测量设备的可靠性。本文主要介绍170 mm 长短磁铁的物理及结构、电流引线、失超保护以及超导磁铁裸磁铁的低温垂直测试情况。目前有两块超导短磁铁，两个超导腔已装入到测试恒温器中，并实现了2.1 K 下的低温运行，超导磁铁的运行平稳，电流引线常温端也无结霜现象。%Background: The Accelerator Driven Subcritical System (ADS) uses a proton beam incident on a target to produce neutrons used in a nuclear reactor to process spent fuel in two ways: to accelerate its decomposition into non-radioactive waste, and to increase the rate at which it is recycled into nuclear fuel. Two cryomodules, each consisting of 7 superconducting spoke cavities, 7 superconducting magnets and 7 beam position monitors, are used to accelerate the proton beams from 3.2 MeV to 10 MeV. The superconducting magnet contains a solenoid for beam focusing and two correctors for orbit correction, it is a key component for ADS injection. Purpose: This study aims at a short superconducting magnet design to meet the required integral field strength and to reduce the leakage field at the nearby superconducting spoke cavities. The design current for the solenoid is 210 A. Methods: The main solenoid and two bucking solenoids plus the iron yoke were used to meet the leakage field requirements which is less than 1 G at a distance of 270 mm from the solenoid center. In order to shorten the magnet length to 170 mm, special design methods were taken for the magnet cryostat by removing two conflicts flanges and replacing them with the direct Al ring seal methods. A kind of conducted the current leads similar as that of Large Hadron Collider (LHC) corrector magnets was applied to the 2.1-K, 3 100-Pa cryogenic system. The small store energy magnet led to the introduction of active quench detected system, which is much more reliable. Two short magnets and two spoke cavities were installed inside a test cryomodule to test the online operation properties of the SC magnet and the SC spoke cavity. Results: A quench performance in the vertical test shows that the operating current of the solenoid magnet can reach above 300 A after natural quenching on three occasions during current ramping (260 A, 268 A and 308 A). Online operating test shows that two magnets can work at 4.2 K and 2.1 K, respectively. The quench protection system worked well when two quenches occurred as the liquid helium level decreased. Conclusion: The online operation for the two magnets confirms the physical and the mechanical design, the reliability of the quench detection technique.
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