Analysis on the cooling water system operation under the first time test of 40 Tesla hybrid magnet

The hybrid magnet of the High Magnetic Field Laboratory has reached its premier goal of 40 T. A detailed analysis has been carried on the cooling water system for insert resistive magnet, and about the de-ionized water quality, the time for purification and the operation parameters. Some phenomena and problems during the resistive magnet excitation have been analyzed. The de-ionized water resistivity presents a continuous declination trend. The flow rate of the de-ionized water and the heat load in both sides of the heat exchanger is imbalance. Some possible reasons were given. The further improvement methods and measures to some problems of the system have been proposed.