Creepy (not KREEPy) Gold-Indium Intermetallic Compounds on Secondary Ion Mass Spectrometry Samples

A series of Secondary Ion Mass Spectrometry (SIMS) sessions to measure hydrogen (H) in Martian meteorite minerals was completed using the Cameca 6f SIMS and NanoSIMS 50L at Arizona State University (ASU). During these sessions, a creeping phenomenon has occurred, where the edges of samples pressed in indium are covered by a metal alloy. We summarize these observations herein, present a collection of preliminary data, and discuss explanations and concerns for future SIMS work. We conclude the report with a research plan for further study

Atom-molecule conversion with particle losses

Based on the mean-field approximation and the phase space analysis, we study the dynamics of an atom-molecule conversion system subject to particle loss. Starting from the many-body dynamics described by a master equation, an effective nonlinear Schr\"odinger equation is introduced. The classical phase space is then specified and classified by fixed points. The boundary, which separate different dynamical regimes have been calculated and discussed. The effect of particle loss on the conversion efficiency and the self-trapping is explored.Comment: 6 pages, 5 figure

Bilateral symmetry breaking in a nonlinear Fabry-Perot cavity exhibiting optical tristability

We show the existence of a region in the parameter space that defines the field dynamics in a Fabry-Perot cylindrical cavity, where three output stable stationary states of the light are possible for a given localized incident field. Two of these states do not preserve the bilateral (i.e. left-right) symmetry of the entire system. These broken-symmetry states are the high-transmission nonlinear modes of the system. We also discuss how to excite these states.Comment: 5 pages, 5 figure

Derivation of the formyl-group oxygen of chlorophyll b from molecular oxygen in greening leaves of a higher plant (Zea mays)

Using mass spectroscopy, we demonstrate as much as 93% enrichment of the 7-formyl group oxygen of chlorophyll b when dark-grown, etiolated maize leaves are greened under white light in the presence of 18O2. This suggests that a mono-oxygenase is involved in the oxidation of its methyl group precursor. The concomitant enrichment of about 75% of the 131-oxygen confirms the well-documented finding that this oxo group, in both chlorophyll a and b, also arises from O2. High 18O enrichment into the 7-formyl oxygen relative to the substrate 18O2 was achieved by optimization of the greening conditions in combination with a reductive extraction procedure. It indicates not only a single pathway for Chl b formyl group formation, but also unequivocally demonstrates that molecular oxygen is the sole precursor of the 7-formyl oxygen

The cryogenic system for the SLAC E158 experiment

E158 is a fixed target experiment at SLAC in which high energy (up to 48 GeV) polarized electrons are scattered off the unpolarized electrons in a 1.5 m long liquid hydrogen target. The total volume of liquid hydrogen in the system is 47.1. The beam can deposit as much as 700 W into the liquid hydrogen. Among the requirements for the system are: that density fluctuations in the liquid hydrogen be kept to a minimum, that the target can be moved out of the beam line while cold and replaced to within 2 mm and that the target survive lifetime radiation doses of up to 1×106 Gy. The cryogenic system for the experiment consists of the target itself, the cryostat containing the target, a refurbished CTI 4000 refrigerator providing more than 1 kW of cooling at 20 K and associated transfer lines and valve boxes. This paper discusses the requirements, design, construction, testing and operation of the cryogenic system. The unique features of the design associated with hydrogen safety and the high radiation field in which the target resides are also covered

A speed-of-play limit reduces gambling expenditure in an online roulette game: Results of an online experiment

UK online casino games are presently not subject to any limitations on speed-of-play or stakes. One recent policy proposal is to ensure that no online casino game can be played faster than its in-person equivalent. Another policy proposal is to limit the maximum stakes on online casino games to £2, to match the current stake limit on electronic gambling machines. This research experimentally investigated the speed-of-play proposal subject to a £2 stake limit, in an online experiment using incentivized payouts based on £4 endowments and a commercial online roulette game, which was slowed-down in one condition to enforce a speed-of-play limit of one spin every 60 seconds. UK residents, aged 18 years and over and with experience in playing online roulette (N = 1,002), were recruited from an online crowdsourcing panel. In the slowed-down condition there was a credible reduction in the amount gambled. This effect occurred via a credible reduction in the mean number of spins which outweighed any potential increases in bet sizes. Speed-of-play limits may be effective in reducing gambling expenditure for online roulette

Knight Shift Anomalies in Heavy Electron Materials

We calculate non-linear Knight Shift $K$ vs. susceptibility $\chi$ anomalies for Ce ions possessing local moments in metals. The ions are modeled with the Anderson Hamiltonian and studied within the non-crossing approximation (NCA). The $K-vs.- \chi$ non-linearity diminishes with decreasing Kondo temperature $T_0$ and nuclear spin- local moment separation. Treating the Ce ions as an incoherent array in CeSn$_3$, we find excellent agreement with the observed Sn $K(T)$ data.Comment: 4 pages, Revtex, 3 figures available upon request from [email protected]

The Screening Cloud in the k-Channel Kondo Model: Perturbative and Large-k Results

We demonstrate the existence of a large Kondo screening cloud in the k-channel Kondo model using both renormalization group improved perturbation theory and the large-k limit. We study position (r) dependent spin Green's functions in both static and equal time cases. The equal-time Green's function provides a natural definition of the screening cloud profile, in which the large Kondo scale appears. At large distances it consists of both a slowly varying piece and a piece which oscillates at twice the Fermi wave-vector. This function is calculated at all r in the large-k limit. Static Green's functions (Knight shift or susceptibility) consist only of a term oscillating at 2kF, and appear to factorize into a function of r times a function of T for rT << vF, in agreement with NMR experiments. Most of the integrated susceptibility comes from the impurity-impurity part with conduction electron contributions suppressed by powers of the bare Kondo coupling. The single-channel and overscreened multi-channel cases are rather similar although anomalous power-laws occur in the latter case at large r and low T due to irrelevant operator corrections.Comment: 22 Revtex pages, 12 figure

Design, development and demonstration of a warm gas distribution system Quarterly report, period ending 31 Mar. 1968

Component tests and system assembly for hydrazine fuel gas distribution system of torque generator for spacecraft attitude contro