Search results for "Synchro"
showing 10 items of 886 documents
Afterglow model for the radio emission from the jetted tidal disruption candidate Swift J1644+57
2012
The recent transient event Swift J1644+57 has been interpreted as emission from a collimated relativistic jet, powered by the sudden onset of accretion onto a supermassive black hole following the tidal disruption of a star. Here we model the radio-microwave emission as synchrotron radiation produced by the shock interaction between the jet and the gaseous circumnuclear medium (CNM). At early times after the onset of the jet (t < 5-10 days) a reverse shock propagates through and decelerates the ejecta, while at later times the outflow approaches the Blandford-McKee self-similar evolution (possibly modified by additional late energy injection). The achromatic break in the radio light curve o…
Numerical study of emission and dynamics from a TDE-powered jet
2012
A transient event Swift J1644+57 is thought to be caused by the emission from a collimated relativistic jet. The jet, powered by the sudden onset of accretion onto a supermassive black hole following the tidal disruption of a star, collides with the gaseous circumnuclear medium and produces forward and reverse shocks which emit synchrotron radiation. We perform 1D and 2D relativistic hydrodynamic simulations using the MRGENESIS code. The aim of the simulations is to study the dynamics of a jet thought to exist in transient events such as Swift J1644+57, as discussed in recent literature. We discuss 1D and 2D jet evolution, on-axis radio light curves and differences between 1D and 2D jet dyn…
Design of a double-gap Hughes-type coupled-cavity for a Ka-band Extended Interaction Klystron
2020
In this paper, the design of a Ka-band Extended-Interaction Klystron (EIK) working at 2$\pi$ mode. The interaction structure is a three-gap Hughes-type coupled-cavity. Based on the results obtained with the 3D model developed by using CST, “cold electrical parameters” have been calculated, necessary to measure the interaction with the electron beam. The structure stability and the synchronization with the electron beam are analyzed The large-signal analysis is performed by 1D software AJDISK. Under the beam voltage and current of 19.55 kV and 0.95 A, respectively, an RF output power value of 3.86 kW and a bandwidth gain value of 37. 06 dB have been obtained
Investigating surface magnetism by means of photoexcitation electron emission microscopy
2002
The imaging of surfaces by means of photoexcitation electron emission microscopy (PEEM) has recently received considerable interest. This is mainly due to the extended use and availability of brilliant synchrotron radiation in the soft x-ray regime which generally facilitates studies with surface specificity and chemical selectivity. The most popular application of the x-ray PEEM (XPEEM) technique concerns studies of magnetic systems and phenomena. By exploiting the high degree of circular or linear polarization of the synchrotron light, the magnetic microstructure in both ferromagnets and antiferromagnets can be visualized. In this contribution we demonstrate the unique potential and the v…
Nuclear Magnetic Moment ofTl207
1985
The magnetic moment 1.876(5)${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$ of 4.77-min $^{207}\mathrm{Tl}$, the only heavy nucleus with a doubly magic core plus a single ${s}_{\frac{1}{2}}$ particle or hole, was measured from the hfs by collinear fast-beam laser spectroscopy at ISOLDE (isotope separator at the CERN synchrotron). The result is of theoretical importance as a test case for core polarization since the nuclear structure is relatively simple and the orbital part of the magnetic moment, including strong pion-exchange contribution, is expected to be zero.
Accessing fast magnetization dynamics by XPEEM: Status and perspectives
2006
Abstract Being already well established as a versatile technique for high-resolution static magnetic domain imaging, X-ray photoemission electron microscopy (XPEEM) is now also capturing the field of time-resolved magnetic investigations. Using appropriate operation modes at synchrotron radiation sources, a time resolution of 10 ps and less can be achieved in recent magnetodynamics studies, giving access even to phenomena involving precessional processes.
MALTA: an asynchronous readout CMOS monolithic pixel detector for the ATLAS High-Luminosity upgrade
2019
The ATLAS collaboration is currently investigating CMOS monolithic pixel sensors for the outermost layer of the upgrade of its Inner Tracker (ITk). For this application, two large scale prototypes featuring small collection electrode have been produced in a radiation-hard process modification of a standard 0.18 μm CMOS imaging technology: the MALTA, with a novel asynchronous readout, and the TJ MONOPIX, based on the well established "column-drain" architecture. The MALTA chip is the first full-scale prototype suitable for the development of a monolithic module for the ITk. It features a fast and low-power front-end, an architecture designed to cope with an hit-rate up to 2 MHz/mm2 without c…
Synchronization of Bioelectric Oscillations in Networks of Nonexcitable Cells: From Single-Cell to Multicellular States.
2019
Biological networks use collective oscillations for information processing tasks. In particular, oscillatory membrane potentials have been observed in nonexcitable cells and bacterial communities where specific ion channel proteins contribute to the bioelectric coordination of large populations. We aim at describing theoretically the oscillatory spatiotemporal patterns that emerge at the multicellular level from the single-cell bioelectric dynamics. To this end, we focus on two key questions: (i) What single-cell properties are relevant to multicellular behavior? (ii) What properties defined at the multicellular level can allow an external control of the bioelectric dynamics? In particular,…
Nuclear Modification ofψ′,χc, andJ/ψProduction ind+AuCollisions atsNN=200 GeV
2013
We present results for three charmonia states (psi' chi(c), and J/ psi) in d + Au collisions at vertical bar y vertical bar < 0.35 and root s(NN) = 200 GeV. We find that the modification of the psi' yield relative to that of the J/ psi scales approximately with charged particle multiplicity at midrapidity across p + A, d + Au, and A + A results from the Super Proton Synchrotron and the Relativistic Heavy Ion Collider. In large-impact-parameter collisions we observe a similar suppression for the psi' and J/ psi, while in small-impact-parameter collisions the more weakly bound psi' is more strongly suppressed. Owing to the short time spent traversing the Au nucleus, the larger psi' suppressio…
Quantum Stochastic Resonance in a Micromaser
1998
We demonstrate that quantum stochastic resonance allows for the noise-controlled synchronization of quantum jumps between the metastable states of the quantized radiation field in a micromaser. Under readily accessible experimental conditions optimal synchronization is achieved at a finite temperature $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}500\mathrm{mK}$ of the environment.