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 conductor and dissolved oxygen, the deposition of copper oxides and the electric resistance are measured for heated copper strips. The same measurements were done for a miniature Bitter coil. The lower the cooling water temperature, the more copper oxide deposited. The oxidation was more pronounced at the part near the water inlet than outlet. The oxidation was not observed in the experiment with nitrogen gas bubbling. In the actual water-cooled magnets with nitrogen gas bubbling, the magnets´ lives are clearly extended