LONGEVITY OF HIGH-POWER RESISTIVE MAGNETS COOLED BY OXYGEN-FREE WATER

The lifetime of a water-cooled magnet is affected by dissolved oxygen in the cooling water. To analyze the relation between oxidation of a c onductor and dissolved oxygen, the deposition of copper oxides and the electric resistance are measured for heated copper strips. The same m easurements were done for a miniature Bitter coil. The lower the cooli ng water temperature, the more copper oxide deposited. The oxidation w as more pronounced at the part near the water inlet than outlet. The o xidation was not observed in the experiment with nitrogen gas bubbling . In the actual water-cooled magnets with nitrogen gas bubbling, the m agnets' lives are clearly extended.