Effect of Bohm potential on a charged gas

Bohm's interpretation of Quantum Mechanics leads to the derivation of a Quantum Kinetic Equation (QKE): in the present work, propagation of waves in charged quantum gases is investigated starting from this QKE. Dispersion relations are derived for fully and weakly degenerate fermions and bosons (these latter above critical temperature), and the differences underlined. Use of a kinetic equation permits investigation of "Landau-type" damping: it is found that the presence of damping in fermion gases is dependent upon the degree of degeneracy, whereas it is always present in boson gases. In fully degenerate fermions a phenomenon appears that is akin to the "zero sound" propagation.Comment: 11 pages, no figures, pdf forma

On the calibration measurement of stripline beam position monitor for the ELI-NP facility

Stripline Beam Position Monitor (BPM) will be installed in the Compton Gamma Source in construction at the ELI Nuclear Physics facility in Romania. A test bench for the calibration of BPM has been built to characterize the device with stretched wire measurement in order to get the BPM response map. A full S-parameters characterization is performed as well to measure the electrical offset with the “Lambertson method”. This paper discusses the extensive simulations performed with full 3D electromagnetic CAD codes of the above measurements to investigate measurement accuracy, possible measurement artefacts and beam position reconstruction

Energy Lost by a Particle Beam in a Lossy Coaxial Liner with Many Holes

In the framework of Bethe's modified theory we study the energy lost by a relativistic particle beam travelling in a coaxial liner with many holes, including the effect of attenuation in the coaxial r egion. The interference among the holes is the main source of losses and is affected by the attenuation in the coaxial only on sufficiently long distances. We derive analytical formulae for all the in teresting quantities and a particular attention is given in clarifying the physical meaning; numerical examples are considered using the LHC nominal parameters

Study of plasma wakefield acceleration mechanism for emittance dominated regimes via hybrid and pic simulations

Electron plasma wakefield acceleration (PWFA) mechanism is a promising non conventional acceleration scheme. Nonetheless further investigation is still needed to fully uncover the instability mechanisms so to mitigate them and make PWFA an effective tool. This work focuses in this direction, we discuss the necessity to use well matched driver bunches to further mitigate witness instabilities. Specifically we propose to inject driver bunches with larger emittance than the matched one (overcompressed bunch) so to let the system reach the matching condition by itself. This preliminary results lead us to the following consideration: while a limited number of cases can be studied with a particle-in-cell code, we understand the necessity for fast systematic analysis: we briefly introduce the hybrid code Architect

Antiepileptic drugs and pregnancy. Population based pharmaco-epidemiological study on prescription patterns, pregnancy outcome and foetal health

Aims of the study: To assess the prevalence of Antiepileptic Drug (AED) exposure in pregnant women with or without epilepsy and the comparative risk of terminations of pregnancy (TOPs), spontaneous abortions, stillbirth, major congenital malformations (MCMs) and foetal growth retardation (FGR) following intrauterine AED exposure in the Emilia Romagna region (RER), Northern Italy (4 million inhabitants). Methods: Data were obtained from official regional registries: Certificate of Delivery Assistance, Hospital Discharge Card, reimbursed prescription databases and Registry of Congenital Malformations. We identified all the deliveries, hospitalized abortions and MCMs occurred between January 2009 and December 2011. Results: We identified 145,243 pregnancies: 111,284 deliveries (112,845 live births and 279 stillbirths), 16408 spontaneous abortions and 17551 TOPs. Six hundred and eleven pregnancies (0.42% 95% Cl: 0.39-0.46) were exposed to AEDs. Twenty-one per cent of pregnancies ended in TOP in the AED group vs 12% in the non-exposed (OR:2.24; CI 1.41-3.56). The rate of spontaneous abortions and stillbirth was comparable in the two groups. Three hundred fifty-three babies (0.31%, 95% CI: 0.28-0.35) were exposed to AEDs during the first trimester. The rate of MCMs was 2.3% in the AED group (2.2% in babies exposed to monotherapy and 3.1% in babies exposed to polytherapy) vs 2.0% in the non-exposed. The risk of FGR was 12.7 % in the exposed group compared to 10% in the non-exposed. Discussion and Conclusion: The prevalence of AED exposure in pregnancy in the RER was 0.42%. The rate of MCMs in children exposed to AEDs in utero was almost superimposable to the one of the non-exposed, however polytherapy carried a slightly increased risk . The rate of TOPs was significantly higher in the exposed women. Further studies are needed to clarify whether this high rate reflects a higher rate of MCMs detected prenatally or other more elusive reasons

The Canadian constitutional history and its determinants

The essay analyses the Canadian constitutional history and focuses on the key-elements that have most influenced the development of Canadian constitutional law. In particular, it highlights how the qu\ue9b\ue9coise question was the first and fundamental determinant of the constitutional order of the Nation. Subsequently, the suggestions coming from the United States and above all the question of independence from the Motherland played an equally significant role. However, the qu\ue9b\ue9coise question reemerges strongly when the process leading to independence from the United Kingdom comes to a positive end

Conductor losses calculation in two-dimensional simulations of H-plane rectangular waveguides

This paper presents a novel numerical approach to simulate H-plane rectangular-waveguide microwave circuits considering a reduced quasi-2D simulation domain with benefits for computational cost and time. With the aim to evaluate the attenuation of the full height 3D component, we propose a modified expression for the waveguide top/bottom wall conductivity. Numerical 2D simulations are validated against results from full wave 3-D commercial electromagnetic simulator. After a benchmark on a simple straight waveguide model, the method has been successfully applied to an asymmetric un-balanced power splitter, where an accurate power loss prediction is mandatory. Simulation time and memory consumption can be reduced by a factor ten and seven respectively, in comparison with complete 3D geometries. Finally, we show that, also for quasi-2D E-bend waveguide, a case where the translational H-plane symmetry is broken, the error on conductor losses computation is mitigated by our approach since the method remains still valid in a first approximation