Multiorbital tunneling ionization of the CO molecule

We coincidently measure the molecular frame photoelectron angular distribution and the ion sum-momentum distribution of single and double ionization of CO molecules by using circularly and elliptically polarized femtosecond laser pulses, respectively. The orientation dependent ionization rates for various kinetic energy releases allow us to individually identify the ionizations of multiple orbitals, ranging from the highest occupied to the next two lower-lying molecular orbitals for various channels observed in our experiments. Not only the emission of a single electron, but also the sequential tunneling dynamics of two electrons from multiple orbitals are traced step by step. Our results confirm that the shape of the ionizing orbitals determine the strong laser field tunneling ionization in the CO molecule, whereas the linear Stark effect plays a minor role.Comment: This paper has been accepted for publication by Physical Review Letter

Role of Endothelial Nitric Oxide Synthase Gene Polymorphisms (Glu298Asp) in Egyptian Patients with Recurrent Spontaneous Abortion

Background: Previous studies indicated an association between endothelial nitric oxide synthase (eNOS) activity and maintenance of pregnancy, but it is rather controversial whether polymorphisms of the gene encoding for eNOS are associated with recurrent spontaneous abortions (RSAs). Aim: The aim was to investigate whether the presence of maternal polymorphism Glu298Asp in exon seven of the eNOS gene increase the risk of RSA in Egyptian women.Subjects and Methods: Hundreds women were randomly selected as the case group. They had at least three RSA before 20th weeks of gestation, same partner and at least one live birth and compared with 100 women, same age range, with no history of abortions or complicated pregnancy as control group. All were investigated for the polymorphism using the polymerase chain reaction‑restriction fragment length polymorphisms method. Data were expressed descriptively as percentages for qualitative values and mean ± standard deviation for quantitative parametric data and comparison of qualitative data was done. Results: Frequency of GG genotype 50/100% in cases and 67/100% in control group. Heterozygous GT frequency was 46/100% in cases and 26/100% in control (P ≤ 0.01, odds ratio [OR] =2.37, and 95% confidence interval [CI] =1.30–4.34). Homozygous TT was 4/100% in the cases and at 7/100% in control (P = 0.68, OR = 0.77, and 95% CI = 0.21–2.76). GG genotype versus GT and GG (P = 0.01, OR = 2.03, and 95% CI = 1.15–3.60). Cases with TT genotype were more susceptible to abortion at an older age with a mean of 29 (4.76) (P = 0.02). Conclusion: In conclusion, (eNOS) Glu298Asp polymorphism was found to be associated with increased risk of RSA in this sample of Egyptian women.KEY WORDS: Endothelial nitric oxide, polymorphism, recurrent spontaneous abortions, synthas

Single photon double ionization of the helium dimer

We show that a single photon can ionize the two helium atoms of the helium dimer in a distance up to 10 {\deg}A. The energy sharing among the electrons, the angular distributions of the ions and electrons as well as comparison with electron impact data for helium atoms suggest a knock-off type double ionization process. The Coulomb explosion imaging of He_2 provides a direct view of the nuclear wave function of this by far most extended and most diffuse of all naturally existing molecules.Comment: 10 pages, 5 figure

Breakup Conditions of Projectile Spectators from Dynamical Observables

Momenta and masses of heavy projectile fragments (Z >= 8), produced in collisions of 197Au with C, Al, Cu and Pb targets at E/A = 600 MeV, were determined with the ALADIN magnetic spectrometer at SIS. An analysis of kinematic correlations between the two and three heaviest projectile fragments in their rest frame was performed. The sensitivity of these correlations to the conditions at breakup was verified within the schematic SOS-model. The data were compared to calculations with statistical multifragmentation models and to classical three-body calculations. Classical trajectory calculations reproduce the dynamical observables. The deduced breakup parameters, however, differ considerably from those assumed in the statistical multifragmentation models which describe the charge correlations. If, on the other hand, the analysis of kinematic and charge correlations is performed for events with two and three heavy fragments produced by statistical multifragmentation codes, a good agreement with the data is found with the exception that the fluctuation widths of the intrinsic fragment energies are significantly underestimated. A new version of the multifragmentation code MCFRAG was therefore used to investigate the potential role of angular momentum at the breakup stage. If a mean angular momentum of 0.75$\hbar$/nucleon is added to the system, the energy fluctuations can be reproduced, but at the same time the charge partitions are modified and deviate from the data. PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.Ld, 25.75.-qComment: 38 pages, RevTeX with 21 included figures; Also available from http://www-kp3.gsi.de/www/kp3/aladin_publications.htm

A measurement of the evolution of Interatomic Coulombic Decay in the time domain

During the last 15 years a novel decay mechanism of excited atoms has been discovered and investigated. This so called ''Interatomic Coulombic Decay'' (ICD) involves the chemical environment of the electronically excited atom: the excitation energy is transferred (in many cases over long distances) to a neighbor of the initially excited particle usually ionizing that neighbor. It turned out that ICD is a very common decay route in nature as it occurs across van-der-Waals and hydrogen bonds. The time evolution of ICD is predicted to be highly complex, as its efficiency strongly depends on the distance of the atoms involved and this distance typically changes during the decay. Here we present the first direct measurement of the temporal evolution of ICD using a novel experimental approach.Comment: 6 pages, 4 figures, submitted to PR

Influence of NCM Particle Cracking on Kinetics of Lithium-Ion Batteries with Liquid or Solid Electrolyte

In liquid electrolyte-type lithium-ion batteries, Nickel-rich NCM (Li$_{1+x }$(Ni$_{1−y−z}$Co$_{ y}$Mnz)$_{1−x}$O$_{2}$) as cathode active material allows for high discharge capacities and good material utilization, while solid-state batteries perform worse despite the past efforts in improving solid electrolyte conductivity and stability. In this work, we identify major reasons for this discrepancy by investigating the lithium transport kinetics in NCM-811 as typical Ni-rich material. During the first charge of battery half-cells, cracks form and are filled by the liquid electrolyte distributing inside the secondary particles of NCM. This drastically improves both the lithium chemical diffusion and charge transfer kinetics by increasing the electrochemically active surface area and reducing the effective particle size. Solid-state batteries are not affected by these cracks because of the mechanical rigidity of solid electrolytes. Hence, secondary particle cracking improves the initial charge and discharge kinetics of NCM in liquid electrolytes, while it degrades the corresponding kinetics in solid electrolytes. Accounting for these kinetic limitations by combining galvanostatic and potentiostatic discharge, we show that Coulombic efficiencies of about 89% at discharge capacities of about 173 mAh g$_{1+x }$NCM$^{-1}$ can be reached in solid-state battery half-cells with LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_{2}$ as cathode active material and Li$_{6}$PS$_{5}$Cl as solid electrolyte