H. P. Godfried

Improved adhesion of thin conformal organic films to metal surfaces

A technique is described for attaching thin, conformal, pin‐hole‐free electrically insulating polyethylene films to flat gold surfaces (previously modified by adsorption of a monolayer of an organic disulfide) by plasma polymerization. These polyethylene films are tough enough to support the attachment of gold electrodes.

A hydrogen maser at temperatures below 1 K

We describe a hydrogen maser oscillator that has been designed to operate as a highly stable clock operating at temperatures below 1 K using a film of superfluid helium 4 as a storage volume wall coating. We derive the expressions that predict the statistically determined frequency stability of the maser in terms of the masers internal parameters. Our design follows conventional atomic beam state selection techniques for supplying atoms in the F = 1, m F = 0 hyperfine sublevel to the oscillating region, which is located inside a sapphire dielectrically loaded TE 011 -mode cavity resonator. Measurements of the Hydrogen-Helium wallshift and the line Q of the maser oscillator have been made with unsaturated superfluid helium films at temperatures between 0.475 and 0.575 K. These show that the wallshift depends strongly on film thickness and that the Q of the maser oscillator improves very rapidly as film thickness is increased.

Rotational R‐branch spectroscopy in CO2: Reply

A reply to the comments of Altman et al., regarding a previous measurement of the rotational Raman spectra of CO42 is given. The resolution and accuracy of measurements4 is stressed. (AIP)