High-precision calculations of In I and Sn II atomic properties

We use all-order relativistic many-body perturbation theory to study 5s^2 nl configurations of In I and Sn II. Energies, E1-amplitudes, and hyperfine constants are calculated using all-order method, which accounts for single and double excitations of the Dirac-Fock wave functions.Comment: 10 pages, accepted to PRA; v2: Introduction changed, references adde

Using pulse-shape information for reconstructing cosmic-ray air showers and validating antenna responses with LOFAR and SKA

The Low Frequency Array (LOFAR) is capable of measuring extensive air showers through their radio emission in the frequency range of 30–80 MHz, while the Square Kilometer Array (SKA) will be able to expand this range to 50–350 MHz. A very important characteristic of cosmic rays is the mass of the primary particle, which is associated with the atmospheric depth of the shower maximum (max). The standard max reconstruction procedure with LOFAR involves the use of a library of CORSIKA/CoREAS simulations for a specific measured event and uses the energy deposited to the ground in terms of radio fluence. In this study, to extract information about shower development, not only the energy fluence is considered but the possibility of using information from the pulse shape is investigated in both frequency ranges (30–80 MHz and 50–350 MHz). The study of the pulse shape through the pulse agreement of measured data and simulations also provides a way to diagnose the proper functioning of individual LOFAR dipoles

Radio Emission Reveals Inner Meter-Scale Structure of Negative Lightning Leader Steps

We use the Low Frequency Array (LOFAR) to probe the dynamics of the stepping process of negatively charged plasma channels (negative leaders) in a lightning discharge. We observe that at each step of a leader, multiple pulses of vhf (30-80 MHz) radiation are emitted in short-duration bursts (&lt;10 mu s). This is evidence for streamer formation during corona flashes that occur with each leader step, which has not been observed before in natural lightning and it could help explain x-ray emission from lightning leaders, as x rays from laboratory leaders tend to be associated with corona flashes. Surprisingly, we find that the stepping length is very similar to what was observed near the ground, however with a stepping time that is considerably larger, which as yet is not understood. These results will help to improve lightning propagation models, and eventually lightning protection models.</p

Rapid, high sensitivity, point-of-care test for cardiac troponin based on optomagnetic biosensor

Abstract BACKGROUND: We present a prototype handheld device based on a newly develope

Correction : Neuroprotection by Argon Ventilation after Perinatal Asphyxia: A Safety Study in Newborn Piglets

[This corrects the article DOI: 10.1371/journal.pone.0113575.]

Decay of oriented Rydberg wave-packets excited with far-infrared radiation.

Transitions from bound atomic Rydberg Stark states in a static electric field to autoionizing Rydberg states above the electric-field-induced ionization threshold are studied using a broadband, tunable free-electron laser (photon energy 160-1400 cm(-1), pulse duration similar to 1 ps) and compared with multichannel quantum defect theory calculations. An atomic streak camera is used to record the time-resolved electron emission transients of the autoionizing atoms. For Stark states located on the downfield side of the potential, the far-infrared ionization spectrum is found to be smooth and the electron emission prompt (<2 ps), whereas for Stark states located on the upfield side, the far-infrared spectrum has sharp resonances, and the lifetime of the quasicontinuum states is considerably longer. The electron-emission transients from optical ionization of ground-state atoms are compared to transients from far-infrared ionization of Rydberg atoms, showing that the angular motion of the wave packet is responsible for the ionization dynamics for both cases, but different coherent superpositions of angular momentum states are excited depending on the initial state. Finally, we discuss the feasability of using Rydberg atoms as an ultrafast far-infrared detector, starting from a downfield state, or as a wavelength-selective detector, starting from an upheld state