Noble Gas Clusters and Nanoplasmas in High Harmonic Generation

We report a study of high harmonic generation from noble gas clusters of xenon atoms in a gas jet. Harmonic spectra were investigated as a function of backing pressure, showing spectral shifts due to the nanoplasma electrons in the clusters. At certain value of laser intensity this process may oppose the effect of the well-known ionization-induced blueshift. In addition, these cluster-induced harmonic redshifts may give the possibility to estimate cluster density and cluster size in the laser-gas jet interaction range.Comment: 5 pages, 4 figure

Measurement of ion emission from plasmas obtained with a 600 fs KrF laser

Ion emission from plasmas obtained by the use of a 600 fs, 36 mJ KrF laser operating at 248 nm was measured and analysed for a variety of targets at different laser intensities. The intensity was set by changing the distance between the focusing lens and the target. It was found that the ions emitted originate from impurities and ions from the bulk of the target can be produced only in the subsequent shots. Proton emission was identified from some targets, but the energy of the protons was low (less than 12 keV). A new silicon carbide semiconductor detector proved to be applicable for the collection of the ions

Status of short-pulse KrF amplifier research and development at Hill, Szeged

The small saturation energy density of excimers requires amplifiers of large cross-sections for amplification of short pulses of already medium power. Homogeneous excitation of large volumes of Fluorine-based gas mixtures by discharge pumping is a critical interplay of the properties of both pumping and preionization; generally necessitating an intense, spatially and temporally controlled xray preionization. In the present realization at High Intensity Laser Laboratory (HILL) the stringent intensity requirements of preionization are fulfilled by reducing the pulse duration of the x-ray flash to ~16 ns, and by positioning the x-ray source in the near vicinity of the active volume. By proper choice of the positions of two cylindrical x-ray guns the spatial distribution of preionization can be tuned to (and around) the optimum distribution giving a practical method to compensate for eventual inhomogenities of the E-field of excitation and to tune the discharge to the desired geometry. In this way the realization of a KrF excimer amplifier of ~5 x 4 cm2 cross-section is presented

Pre-Excitation Studies for Rubidium-Plasma Generation

The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (AWAKE) project is the generation of highly uniform plasma from Rubidium vapor. The standard way to achieve full ionization is to use high power laser which can assure the over-barrier-ionization (OBI) along the 10 meters long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi Photon Ionization (REMPI) scheme probably can be realized by much less laser power. In the following the resonant pre-excitations of the Rb atoms are investigated, theoretically and the status report about the preparatory work on the experiment are presented.Comment: 8 pages, 6 figures, submitted to Nucl. Inst. and Meth. in Phys. Res.

Impact of CT-apelin and NT-proBNP on identifying non-responders to cardiac resynchronization therapy

CONTEXT: Assessment of response to cardiac resynchronization therapy (CRT) is essential. OBJECTIVE: To assess the predictive value of CT-apelin together with NT-proBNP in patients undergoing CRT. METHODS: Serum CT-apelin and NT-proBNP were measured by ELISA before, and 6-month after CRT. Primary endpoint was non-response (<4% increase in LVEF) after 6-month. RESULTS: From 81 patients, 15 proved to be non-responders. Six-month CT-apelin was superior compared to NT-proBNP in identifying non-responders by multivariate ROC (CT-apelin:p = 0.01, NT-proBNP:p = 0.13) and by logistic regression (CT-apelin:p = 0.01, NT-proBNP:p = 0.41) analyzes. CONCLUSION: Six-month CT-apelin might be valuable novel biomarker in identifying non-responders to CRT that was superior to NT-proBNP

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe