Mechanical Analysis and Measurements of a Multicomponent NbTi/Cu Superconducting Magnets Structure for the Fully Superconducting Electron Cyclotron Resonance Ion Source

Abstract

A fully superconducting electron cyclotron resonance (ECR) ion source (SECRAL II) is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids (Nb-Ti/Cu) and six superconducting sextupoles (Nb-Ti/Cu). Different from the conventional superconducting ECR magnetic structure, the SECRAL II includes three superconducting solenoid coils that are located inside the superconducting sextupoles. The SECRAL II can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL II generating its self field of ~8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at < 200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL II structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the strains developments of a sextupole is reported. Finally, based on our analysis, the stresses and deformations for its assembly of each SECRAL II coil will be further optimized.

A dynamic strain-based quench-detection method in an LTS sextupole magnet during excitation and quench

“…As shown in figure 1 , one SG and the corresponding compensating dummy gauge were placed onto the outer surface of the NbTi/Cu superconducting wire within the insulated layer for each test location. The results of our previous simulation and analysis showed that the strain distributions on arc and long side of the sextupole are different, and its ends (the arc parts) and centers of long sides are both the most critical ones [57]. Therefore, eight SGs were used for strain test at different positions, as shown in figure 2.…”

Mechanical Analysis and Testing of Conduction-Cooled Superconducting Magnet for Levitation Force Measurement Application

“…The degradation is a great threaten for magnet operation and must be carefully prevented from happening. Considering the importance of this aspect, a detailed mechanical analysis is demanded for designing the superconducting magnet [15][16][17][18].…”

Strain Measurement Method Based on External Symmetrical Compensation Bridge Composed of Strain Gauges with Four-Wire Configuration for a Large-Scale NbTi Superconducting Dipole Magnet Detector

“…Additionally, the authors also developed remote strain measurements of superconducting magnets based on low-temperature resistive strain gauges incorporated with half-active or full-active bridge compensation con gurations and wireless strain instruments to eliminate measurement errors owing to the effects of temperature and magneto-resistance [21]. The developed technology has been utilised for effective strain monitoring in various superconducting magnet systems, such as the Lanzhou Penning ion trap [22], China Accelerator Driven System [23], highly charged fully superconducting ECR ion source [24][25][26], split superconducting magnets in versatile multi eld test facilities [27], and high eld HTS magnet [28][29][30].…”