Search for anisotropic effects of hcp solid helium on optical lines of cesium impurities

The anisotropic effect of a hcp 4He solid matrix on cesium atoms has been proposed as a tool to reveal the parity violating anapole moment of its nucleus. It should also result in splitting the D2 optical excitation line in a way depending on the light polarization. An experimental investigation has been set up using oriented hcp helium crystals in which cesium metal grains are embedded. Atoms are created by laser sputtering from this grains. Optical absorption spectra of the D2 line have been recorded in the temperature range of 1.0 to 1.4 K at liquid/solid coexistence pressure by monitoring the fluorescence on the D2 line at 950 nm. No significant effect of the light polarization has been found, suggesting a statistically isotropic disordered solid environment for the cesium atoms.Comment: The original publication will be available at http://www.springerlink.co

Properties of superfluid fog

A dense fog consisting of superfluid \chem{{}^4 He} droplets can be generated in helium vapor up to a height of 4–6\un{cm} from the helium surface by driving a piezo transducer plate immersed under the liquid. The average droplet size ranges from about 100\un{\mu m} at a drive frequency of 1\un{kHz} to 10\un{\mu m} at 100\un{kHz}, and the frequency dependence is consistent with the capillary-wave dispersion relation of the helium surface, with the droplets ejected from the surface being about one wavelength in diameter. It appears that the helium vapor is set into motion along with the droplets, greatly reducing the viscous drag on the droplets and making possible the substantial fog heights above the surface

Criteres d'utilisation de microalgues pour le nourrissage de crassostrea gigas et d'ostrea edulis en ecloserie

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22543, issue : a.1996 n.51 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Angular Effects in Proton-Induced Single-Event Upsets in Silicon-on-Sapphire and Silicon-on-Insulator Devices

We present new data in the ongoing effort to bound the effect of proton angle of incidence on the single-event upset (SEU) rate in silicon-on-sapphire (SOS) and silicon-on-insulator (SOI) devices