Formation of hydrogen peroxide and water from the reaction of cold hydrogen atoms with solid oxygen at 10K

The reactions of cold H atoms with solid O2 molecules were investigated at 10 K. The formation of H2O2 and H2O has been confirmed by in-situ infrared spectroscopy. We found that the reaction proceeds very efficiently and obtained the effective reaction rates. This is the first clear experimental evidence of the formation of water molecules under conditions mimicking those found in cold interstellar molecular clouds. Based on the experimental results, we discuss the reaction mechanism and astrophysical implications.Comment: 12 pages, 3 Postscript figures, use package amsmath, amssymb, graphic

Measurements of rotational transform due to noninductive toroidal current using motional Stark effect spectroscopy in the Large Helical Device

The change of rotational transform due to noninductive plasma current driven by a negative neutral beam, which has a value typically less than 10% of total rotational transform determined by the external current in the helical coils, is measured in the Large Helical Device with motional Stark effect spectroscopy. Radial profiles of rotational transform are derived from the radial profiles of the polarization angle of the sigma component in the Halpha line emitted from the high energy hydrogen atom of the beam with four sets of linear polarizers, spectrometers, and CCD detectors. The radial profile of the change in the rotational transform due to the noninductive toroidal current driven by the neutral beam is measured

Phase Diagram of Coupled Ladders

The 2-leg t-J ladder forms a spin liquid at half-filling which evolves to a Luther-Emery liquid upon doping. Our aim is to obtain a complete phase diagram for isotropic coupling (i.e. rungs and legs equal) as a function of electron density n and the ratio J/t (>0). Two known limiting cases are: n<1/2 which is a single band Luttinger liquid and small hole doping for J/t close to 0 which is a Nagaoka ferromagnet. Using Lanczos techniques we examine the region between the Nagaoka and Luther-Emery phases for 1>n>1/2. We find evidences for gapless behavior in both spin and charge channels for J/t<0.3 consistent with Luttinger liquids in both bonding and anti-bonding bands (i.e., C2S2). This proposal is based on the behavior of spin and charge correlation functions. For example the hole-hole correlation function which displays hole pairing at larger J/t, shows hole-hole repulsion in this region. As a further test, we examined the dependence of the energy on a relative phase shift between bonding and antibonding bands. For J/t < 0.3 this is very weak, indicating a lack of pairing between these channels.Comment: 21 pages, 18 figure