Design and Test of a 30 T-100 ms Flat-Top Magnet With a Conical Bore at the WHMFC

A magnet has been developed to generate 30 T pulsed magnetic field with 100 ms flat-top at the Wuhan National High Magnetic Field Center (WHMFC). By adjusting the conductor height of each layer, this magnet has a typical bore with 20 mm diameter and a conical bore with 30 degree opening angle on the one side for X-ray diffraction and neutron scattering experiments. Fast cooling technique was used for better cooling performance, and 8 stainless steel rods were placed in the cooling channel to resist the strong axial electromagnetic force. The magnet was connected in series with an auxiliary coil to extend the flat-top duration of the magnetic field, and energized with nineteen 1.25 MJ capacitor modules. The multiple capacitor modules are pre-charged to the set voltage, and then triggered in sequence. Peak field of 30 T with 90 ms flat-top and 1% flatness was obtained with optimized initial voltage and trigger time of each capacitor module.