We suggest a technique to induce effective, controllable interactions between atoms that is based on Raman scattering into an optical mode propagating with a slow group velocity. The resulting excitation corresponds to the creation of spin-flipped atomic pairs in a way that is analogous to correlated photon emission in optical parametric amplification. The technique can be used for fast generat...

Spontaneous emission can create coherences in a multilevel atom having close lying levels, subject to the condition that the atomic dipole matrix elements are non-orthogonal. This condition is rarely met in atomic systems. We report the possibility of bypassing this condition and thereby creating coherences by letting the atom with orthogonal dipoles to interact with the vacuum of a pre-selecte...

The possibility of using a three-level-A-scheme for the excitation of the clock hyper-ne transition in s’Rb is analyzed. The physics involved opens up two distinct avenues useful for the implementation of an atomic frequency standard, avenues based on two distinct phenomena: the electro-magnetically induced transparency (EIT or Dark Line) and the coherent microwave emission (Maser without popul...

Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations of current atomic calculations, particularly those for Fe, all conspire to make this task very difficult. A critical assessment of plasma diagnostics in the c...

An inductively coupled plasma atomic emission spectrometer is used to detect carbon-containing compounds following separation by high-performance liquid chromatography. A calcium form ligand exchange column with distilled and deionized water as the mobile phase is used to separate carbohydrates. The eluting species are detected by monitoring the carbon atomic emission line at 193.09 nm. The mas...

Atmospheric pressure of helium He and methane CH4 mixture discharge characteristics are investigated using emission spectroscopic methods. Plasmas are produced in a radio frequency capacitively coupled device at atmospheric pressure in the ambient air. Without the CH4 gas introduced in the plasma, the emission spectrum exhibits typical helium discharge characteristics showing helium atomic line...

HI 21 cm observations with the NRAO 140 Foot telescope have revealed a giant HI cloud (G28.17+0.05) in the Galactic plane that has unusual properties. The cloud is 150 pc in diameter, is at a distance of 5 kpc, and contains as much as 105M⊙ of atomic hydrogen. The cloud consists of a cold core, T ∼ 10 K, and a hotter outer envelope, T ≥ 200 K. There is no observable difference in the HI line wi...

We report the observation of intense extreme ultraviolet (EUV) emission from incandescently heated atomic hydrogen and atomized strontium. Typically the emission of extreme ultraviolet light from hydrogen gas is achieved via a discharge at high voltage, a high power inductively coupled plasma, or a plasma created and heated to extreme temperatures by RF coupling (e.g. > 10 6 K) with confinement...

We have developed in detail the theory of X-ray line and continuum production due to atomic interactions of accelerated ions, incorporating in our calculations information from a broad range of laboratory measurements. We applied our calculations to the Orion region from which nuclear gamma-ray lines were observed with the COMPTEL instrument on CGRO. The accelerated particles which produce this...

Charge exchange recombination spectroscopy measurements of impurity ion temperature !Ti" and velocity !vi" on the Madison Symmetric Torus present a unique challenge due to two coupled effects: low temperature—typically 300–500 eV, though up to 2 keV in high current plasmas—and a dominant contribution from background, i.e., non charge exchange driven, emission. For low Ti, the background emissio...