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 eight 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.