Long life pulsed high field magnets with CuAg conductor and internal reinforcement

Several pulsed high field magnets for the pulsed field facilities in Australia and Belgium were developed and tested. Based on the requirements of a long life and a regular use at 60 T, the conductor was chosen to be CuAg with Kapton insulation. This conductor was developed by the NRIM, Japan and is presently produced by Showa, Japan. It offers a good combination of conductivity and strength and is available with large cross sections. As a first step, a prototype with 17 mm bore and α=4.8 with conventional internal glass fibre reinforcement was made and tested up to 62 T. The user magnets have a bore of 22 mm and α=4.6. Based on the inductance changes during the training, the field limit for normal operation is set at 58 T. In a next step, a 12 mm bore α=7 magnet was fabricated using carbon fibre as internal reinforcement and a field of 69 T was obtained. The combination with carbon fibre thus opens the possibility of further increasing the peak field of the larger bore magnets. Details of the design criteria and construction of the magnet will be presented