Search results for "electromagnetic [effect]"
showing 10 items of 555 documents
Cross-Kerr nonlinearity in optomechanical systems
2015
We consider the response of a nanomechanical resonator interacting with an electromagnetic cavity via a radiation pressure coupling and a cross-Kerr coupling. Using a mean field approach we solve the dynamics of the system, and show the different corrections coming from the radiation pressure and the cross-Kerr effect to the usually considered linearized dynamics.
Designing spin-spin interactions with one and two dimensional ion crystals in planar micro traps
2011
We discuss the experimental feasibility of quantum simulation with trapped ion crystals, using magnetic field gradients. We describe a micro structured planar ion trap, which contains a central wire loop generating a strong magnetic gradient of about 20 T/m in an ion crystal held about 160 \mu m above the surface. On the theoretical side, we extend a proposal about spin-spin interactions via magnetic gradient induced coupling (MAGIC) [Johanning, et al, J. Phys. B: At. Mol. Opt. Phys. 42 (2009) 154009]. We describe aspects where planar ion traps promise novel physics: Spin-spin coupling strengths of transversal eigenmodes exhibit significant advantages over the coupling schemes in longitudin…
Measurements of inclusive jet spectra in pp and central Pb-Pb collisions at sNN=5.02TeV
2020
This article reports measurements of the pT- differential inclusive jet cross section in pp collisions at √s=5 .02TeV and the pT- differential inclusive jet yield in Pb-Pb 0–10% central collisions at√sNN =5.02TeV. Jets were reconstructed at midrapidity with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm. For ppcollisions, we report jet cross sections for jet resolution parameters R =0.1–0.6 over the range 20 < pT, jet < 140 GeV/c, as well as the jet cross-section ratios of different R and comparisons to two next-to-leading-order (NLO)– based theoretical predictions. For Pb-Pb collisions, we report the R=0.2 and R=0.4 jet spectra for 40 < pT, jet < 1…
Parametric excitation of bending deformations of a rod by periodic twist
2013
A model of a semiflexible magnetic filament with magnetization frozen in the direction perpendicular to the tangent of its center line is formulated. It is shown that if the rod is magnetized at its ends in opposite directions, an AC magnetic field causes parametric excitation of bending deformations. Neutral curves of parametric excitation are calculated both analytically and numerically. The shapes arising upon parametric excitation of bending deformations are chiral. Periodic rotation of the chiral filament due to nonhomogeneous twist in a nonhomogeneous AC field causes its unidirectional motion.
246. Analysis of signal-to-noise ratio for a 2-channels coil developed to enable transcranial Magnetic Resonance-guided Focused Ultrasound Surgery (t…
2018
Abstract Purpose In recent years trans-cranial Magnetic Resonance-guided Focused Ultrasound Surgery (tcMRgFUS) treatments have aroused large scientific and medical interest [1] . Usually, tcMRgFUS systems are integrated with 3 T systems which allow the use of the body RF coil for both real time imaging and MR-thermometry. At University Hospital of Palermo there is the world-first installation of a tcMRgFUS system integrated with a 1.5 T scanner. Here we present the characterization in terms of signal-to-noise ratio (SNR) of a dedicated RF coils suitably developed (by InSightec) to enable tcMRgFUS treatments with 1.5 T MR units. Methods and materials The focused ultrasound equipment (ExAblat…
Evidence of electrical activity on Titan drawn from the Schumann resonances sent by Huygens probe
2008
Abstract A procedure is shown for extracting weak resonances from the responses of electromagnetic systems excited by electric discharges. The procedure, based on analysis of the late-time system response, is first checked using an analytical function and later with the data for the electric field generated by the computational simulation of Titan's atmosphere using the Transmission Line Matrix (TLM) method. Finally, the low frequency spectrum of the natural electric field in Titan's atmosphere sent by the mutual impedance sensor (MIP) included in the Huygens probe is analyzed employing this technique. The MIP sensor was initially designed to measure the horizontal component of the electric…
3-D Shielding Analyses of the Vertical and Mid-Plane Ports in ITER
1996
A three dimensional (3-D) shielding analysis of the International Thermonuclear Experimental Reactor (ITER) has been performed with the aim of calculating the nuclear heating on the magnet system, correlating it to the existing vertical and horizontal ports. When these openings are left unshielded, more than 50 kW are calculated for the upper half of Toroidal Field Coil system and two of the Poloidal Field Coils. A simple plug, with same thickness as of the vacuum vessel can lower the heating to meet the imposed requirements. 5 refs., 6 figs., 4 tabs.
A Ioffe Trap Magnet for the Project 8 Atom Trapping Demonstrator
2020
The goal of the Project 8 experiment (B. Monreal and J. Formaggio, 2009) is to measure the absolute neutrino mass using tritium, which involves precisely measuring the energies of the beta-decay electrons in the high-energy tail of the spectrum (A. A. Esfahani et al. , 2017). The experimental installation of Project 8 Atom Trapping Demonstrator requires a magnet with rather unusual field properties. The magnet has to contain within the cold mass a large volume enclosed by a continuous, uninterrupted boundary higher than 2 T, whereas the field in a substantial volume inside this boundary has to be of the order of 10−4 T or less. A 1-T solenoid field provides the background field necessary fo…
Even harmonics generation of high frequency radiation in current-carrying plasmas
2005
Generation of high frequency radiation harmonics in a current-carrying plasma is studied. The physical mechanism responsible for harmonics generation is provided by electron-ion collisions. The current in the plasma is sustained by a constant electric field. It is shown that the electron distribution function anisotropy due to the static field yields generation of even harmonics. As a result, the radiation spectrum emitted by the current-carrying plasma contains both even and odd harmonics, the latter being attributed to currentless plasma. For a broad range of plasma and high frequency radiation parameters, a detailed analysis of the even harmonics properties is reported.
Full Wave Solution for Intel CPU With a Heat Sink for EMC Investigations
2010
A CPU with a heat sink (e.g. Intel Pentium 4 and Intel Pentium dual core) is a challenging problem for EMC analysis. A Very Large Scale Integrated (VLSI) device was modelled using the Finite Element Method (FEM) frequency domain solver to obtain a 3D full wave solution. The electromagnetic (EM) radiation emitted from these high power microelectronic circuits connected to a heat sink was found to have resonant frequencies around 2.4 GHz and 5 GHz with reflection coefficients less than -19 dB and -8 dB respectively. These resonant frequencies are very close to the operating frequency of both IEEE and Bluetooth wireless communication systems. This paper proposes a new benchmark model based on …