A prototype storage ring for neutral molecules.

The ability to cool and manipulate atoms with light has yielded atom interferometry, precision spectroscopy, Bose-Einstein condensates and atom lasers. The extension of controlled manipulation to molecules is expected to be similarly rewarding, but molecules are not as amenable to manipulation by light owing to a far more complex energy-level spectrum. However, time-varying electric and magnetic fields have been successfully used to control the position and velocity of ions, suggesting that these schemes can also be used to manipulate neutral particles having an electric or magnetic dipole moment.

Vibrational spectroscopy of gas-phase neutral and cationic phenanthrene in their electronic groundstates.

Various experimental methods are applied to retrieve the vibrational structure of phenanthrene in its neutral and cationic groundstates. The linear infrared (IR) absorption spectra in the 400-1650 cm(-1) range of jet-cooled phenanthrene and its cation, both clustered with either an argon or a neon atom, are obtained via photo-induced cluster dissociation spectroscopy. The spectra observed are in good agreement with calculated spectra of the bare species.

Electrostatic trapping of ammonia molecules.

The ability to cool and slow atoms with light for subsequent trapping allows investigations of the properties and interactions of the trapped atoms in unprecedented detail. By contrast, the complex structure of molecules prohibits this type of manipulation, but magnetic trapping of calcium hydride molecules thermalized in ultra-cold buffer gas and optical trapping of caesium dimers generated from ultra-cold caesium atoms have been reported. However, these methods depend on the target molecules being paramagnetic or able to form through the association of atoms amenable to laser cooling, respectively, thus restricting the range of species that can be studied.

Titanium carbide nanocrystals in circumstellar environments.

Meteorites contain micrometer-sized graphite grains with embedded titanium carbide grains. Although isotopic analysis identifies asymptotic giant branch stars as the birth sites of these grains, there is no direct observational identification of these grains in astronomical sources. We report that infrared wavelength spectra of gas-phase titanium carbide nanocrystals derived in the laboratory show a prominent feature at a wavelength of 20.

Structure of nickel layers in ni-C multilayer coatings: influence of annealing.

The structure of Ni-C multilayer and single nickel layer samples has been analyzed before and after annealing, using two techniques: fluorescence EXAFS (F1EXAFS) at the Ni-K. edge and CuKα reflection. Annealing at a temperature of 450°C resulted in a change in the structure of the nickel layers from amorphous like to crystalline like.

Characterization of a Multilayer Coated Laminar Reflection Grating at λ = 0.154 nm.

A laminar grating of 1200 1/mm was coated with an x-ray reflecting multilayer coating. The multilayer coating consisted of 41 alternating layers of ReW and C having a period of 2.3 nm.

Soft X-Ray Emission of Laser-Produced Plasmas: Comparison for 30-ps and 20-ns Laser Pulses.

Soft x-ray emission spectra (250-875 eV) are presented for plasmas, produced by picosecond and nanosecond frequency-doubled Nd:YAG-glass laser pulses incident on 14 different target materials. The emitted spectra have been corrected for various apparatus functions which enables a direct comparison between plasmas produced by pico- and nanosecond laser pulses. The relative integrated emission intensity as a function of Z number, obtained from the corrected spectra, shows an oscillatory behavior, with distinct maxima for those elements exhibiting a dominant line emission in our photon energy window.