William W. Watson

Apparatus for Isotope Separation by Thermal Diffusion

A compact, all‐metal, multi‐stage thermal diffusion apparatus for the separation of isotopes in quantity in non‐corrosive gases at any pressure up to 175 lb/in.2 is described. For a particular gas the proper pressure may be well‐enough calculated in advance as that giving maximum separation factor in the last column only. Operating with neon at 3 atmos. pressure, and using 12 meters of column consuming 4.9 kw for 260 hours, 7 liters of gas with a Ne22 content of 93.4 percent were produced.

Apparatus for Concentration of He3 by Thermal Diffusion

A multistage thermal diffusion apparatus for the concentration of He3 is described. Included is a novel three‐stage, all‐metal column based on a G. E. Calrod heater. Concentration was carried only to a He3/He4 ratio of 0.05 percent, a factor of 3.3×103. The performance indicates the importance of having the hot wall in concentric cylinder columns made of metal of good thermal conductivity to minimize azimuthal temperature gradients which can markedly increase parasitic remixing of the gas if a metal such as stainless steel is used.

Ultraviolet Wave-Length Standards of N, C, and O, λ2300 to λ1080

Wave-lengths of N, C and O lines in the spectral range λ2317 to λ1080 have been determined with an accuracy of 0.01A to serve as wave-length standards in this region. A ten-foot focus normal incidence vacuum spectrograph having a dispersion of 5.5A/mm was used to compare second order N and C lines with first order Cu and Fe interferometer-measured standards. The results are compared with values given by Boyce and Rieke. The mean deviation from their values is 0.009A, the mean systematic deviation 0.001A. The use of the method of coincidences in determining tertiary standards is discussed.