Critical Evaluation and Compilation of Viscosity and Diffusivity Data Semiannual Status Report No. 1, Jul. 1 - Dec. 31, 1965

Compilation and evaluation of diffusivity and viscosity data on gas and liquid turbulent flow system

Nuclear spin relaxation and centrifugal distortion effects in dilute silane gas

We have measured the proton longitudinal spin relaxation rate in dilute gaseous silane (SiH4) between 10−2 and 1 amagats and are able to observe the influence of rotational Q branch centrifugal distortion transitions

Nuclear spin relaxation and centrifugal distortion effects in dilute silane gas

We have measured the proton longitudinal spin relaxation rate in dilute gaseous silane (SiH4) between 10−2 and 1 amagats and are able to observe the influence of rotational Q branch centrifugal distortion transitions

Microfabricated high-finesse optical cavity with open access and small volume

We present a microfabricated optical cavity, which combines a very small mode volume with high finesse. In contrast to other micro-resonators, such as microspheres, the structure we have built gives atoms and molecules direct access to the high-intensity part of the field mode, enabling them to interact strongly with photons in the cavity for the purposes of detection and quantum-coherent manipulation. Light couples directly in and out of the resonator through an optical fiber, avoiding the need for sensitive coupling optics. This renders the cavity particularly attractive as a component of a lab-on-a-chip, and as a node in a quantum network

Observation of the influence of centrifugal distortion of the methane molecule on nuclear spin relaxation in the gas.

The spin–lattice relaxation time T1 was measured in gaseous CH4 as a function of density at room temperature between 0.006 and 7.0 amagats. T1 was found to pass through a minimum near 0.04 amagats in agreement with previous, less precise measurements. The spin–rotation interaction is the dominant relaxation mechanism in gaseous CH4. Since the spin–rotation constants are accurately known for CH4, the relaxation experiments provide a check on the theory of spin–lattice relaxation for spherical top molecules. In the conventional theory, it is assumed that the correlation function of the spin–rotation interaction is a simple exponential function of time. These experiments show that this assumption is not true for CH4 gas. The observed fine structure in the plot of relaxation rate versus density is attributed to the influence of centrifugal distortion of the CH4molecule, which removes the degeneracy of rotational states having the same value of the quantum number J by an amount somewhat greater than the nuclear Larmor frequency of 30 MHz

Observation of the influence of centrifugal distortion of the methane molecule on nuclear spin relaxation in the gas.

The spin–lattice relaxation time T1 was measured in gaseous CH4 as a function of density at room temperature between 0.006 and 7.0 amagats. T1 was found to pass through a minimum near 0.04 amagats in agreement with previous, less precise measurements. The spin–rotation interaction is the dominant relaxation mechanism in gaseous CH4. Since the spin–rotation constants are accurately known for CH4, the relaxation experiments provide a check on the theory of spin–lattice relaxation for spherical top molecules. In the conventional theory, it is assumed that the correlation function of the spin–rotation interaction is a simple exponential function of time. These experiments show that this assumption is not true for CH4 gas. The observed fine structure in the plot of relaxation rate versus density is attributed to the influence of centrifugal distortion of the CH4molecule, which removes the degeneracy of rotational states having the same value of the quantum number J by an amount somewhat greater than the nuclear Larmor frequency of 30 MHz

Observation of the influence of centrifugal distortion of the methane molecule on nuclear spin relaxation in the gas.

The spin–lattice relaxation time T1 was measured in gaseous CH4 as a function of density at room temperature between 0.006 and 7.0 amagats. T1 was found to pass through a minimum near 0.04 amagats in agreement with previous, less precise measurements. The spin–rotation interaction is the dominant relaxation mechanism in gaseous CH4. Since the spin–rotation constants are accurately known for CH4, the relaxation experiments provide a check on the theory of spin–lattice relaxation for spherical top molecules. In the conventional theory, it is assumed that the correlation function of the spin–rotation interaction is a simple exponential function of time. These experiments show that this assumption is not true for CH4 gas. The observed fine structure in the plot of relaxation rate versus density is attributed to the influence of centrifugal distortion of the CH4molecule, which removes the degeneracy of rotational states having the same value of the quantum number J by an amount somewhat greater than the nuclear Larmor frequency of 30 MHz

Deuteron Zeeman Relaxation of CD4 in the Isotropic Liquid, the Liquid Crystalline, and the Solid State of Several Substances

Measurement of deuteron Zeeman relaxation rates of CD4 dissolved in benzene, hexane, and the liquid crystals MBBA, EBBA, and Merck ZLI‐1132 and in pure CD4 gas as a function of temperature at 30.7 and 61.4 MHz shows that the CD4 is uniformly dispersed in the liquid solvents but resides in gas pockets when the solvents are in the solid state. Effects of centrifugal distortion were observed in the gas phase. The relaxation rate was found to be nearly independent of solvent, temperature, and pressure for the methane–liquid mixtures. This result is explained in terms of the extended diffusion model for the combined effects of free molecular rotation and collisions on the spectral density of quadrupolar interactions when the collisional and mean free rotational periods are of the same order of magnitude. It can also be interpreted in terms of the Fokker–Planck–Langevin model for rotational Brownian motion

ICP polishing of silicon for high quality optical resonators on a chip

Miniature concave hollows, made by wet etching silicon through a circular mask, can be used as mirror substrates for building optical micro-cavities on a chip. In this paper we investigate how ICP polishing improves both shape and roughness of the mirror substrates. We characterise the evolution of the surfaces during the ICP polishing using white-light optical profilometry and atomic force microscopy. A surface roughness of 1 nm is reached, which reduces to 0.5 nm after coating with a high reflectivity dielectric. With such smooth mirrors, the optical cavity finesse is now limited by the shape of the underlying mirror