Water Cooled Magnets

Abstract

This paper discusses the construction of water cooled solenoids at power levels ranging from 1 to 100 Mw and with cylindrical inner working spaces having radii ranging from 1 to 10 cm. A first limitation is due to the fact that the power density in the magnet cannot exceed a value set by the surface cooling rate allowable in the water passages. Present designs go up to a power density of 1.5×10⁴ w/cm³ and a surface cooling rate of 1.5×10³ w/cm². With these limitations, useful coils can be built operating at power levels ranging from 1 to 10 Mw and giving fields ranging from 100 to 250 kilogauss. In the range of 200 to 300 kilogauss, Zr‐Cu or Cr‐Cu alloys may be used to avoid plastic deformation at the inner surface. The strengthening and cooling of coils to operate at higher power levels is discussed. A preliminary design is presented for a high precision magnet for nuclear magnetic resonance experiments.