Temperature-Dependence of Critical Currents in Superconducting Bi-2212/Ag Wires

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The ring cyclotron of the Paul Scherrer Institute (PSI) accelerates an intense proton beam from 72MeV up to 590MeV. This happens in four cavities of very high quality factor, oscillating in the fundamental mode. The beam can excite parasitic oscillation modes (HOMs), because of its time structure. Measurements showed that their field can leak out into the vacuum chamber. Until now, there is no tool available to predict the potentially harmful effect of these HOMs onto the beam operation of the cyclotron. It

Measuring the nuclear magnetic resonance spectra of low-gamma heteronuclei such as N-15 constitutes an important analytical tool for the characterization of molecular structure and dynamics. The reduced resonance frequencies and magnetic moments of these heteronuclei, however, make the sensitivity of this kind of spectroscopy inherently lower than that of comparable H-1 NMR observations. A well-known solution to this sensitivity problem is indirect detection: a 2D NMR technique capable of enhancing the sens

We propose an approach for magnetic microbead transport in microfluidic channels over long-range distances using an array of simple planar coils. The latter are placed in a uniform static magnetic field, the role of which is to impose a permanent magnetic moment to the microbeads. The very small magnetic field gradient of a simple planar coil is then sufficient to displace the microbeads. The long-range displacement is assured by arranging adjacent coils in the array with spatial overlap in a three-phase ac

The quasi-1D S = 1/2 antiferromagnet CuGeO3 undergoes a spin-Peierls transition to a dimerised singlet quantum ground state, with S = 1 carrying pairs of domain walls as elementary excitations. Applying a large magnetic field, the domain walls-solitons-can be condensed into the ground state, forming a static incommensurate soliton lattice, which has been investigated by neutron scattering. The static soliton structure was found to be in good accordance to field theoretical and numerical calculations, while

The original magnetic properties of nanometre-sized particles are due to the distinct contributions of volume, surface and step atoms. To disentangle these contributions is an ongoing challenge of materials science. Here we introduce a method enabling the identification. of the remarkably different contributions of surface and perimeter atoms to the magnetic anisotropy energy of two-dimensional nanostructures. Our method uses the generally nonlinear relationship between perimeter length and surface area. At

The orientation dependence of the longitudinal piezoelectric coefficient, d(33)(), is investigated as a function of temperature in BaTiO3 and PbTiO3 crystals using the Landau-Ginsburg-Devonshire theory. We show that a presence of the ferroelectric-ferroelectric phase transitions in BaTiO3 leads to enhanced d(33)() along nonpolar directions. The reason for this is that in the vicinity of a phase transition temperature at which a polarization vector changes its direction (tetragonal-orthorhombic/monoclinic,

We propose in this paper new expressions relating lightning return stroke currents and far radiated electric and magnetic fields, taking into account the presence of an elevated strike object. The derived expressions show that the presence of an elevated strike object enhances the radiated electromagnetic field. The enhancement with respect to a return stroke initiated at ground level is expressed simply through a factor equal to (1+c/v), where v and c are the return stroke speed and the speed of light, res

The electron temperature, pressure and density pro les from an extreme variety of shaped Ohmically heated sawtoothing plasmas in TCV ( Tokamak a Configuration Variable, B-T < 1.5T, R-0 = 0.88 m, a < 0.25 m) are compared to model predictions drawing from two bodies of theory. One of these is based on the assumption of stationary magnetic entropy and predicts sti toroidal current, and consequently Ohmically relaxed electron temperature pro les. The second theory is based on the assumption of approximate conse

The helical distortion of a compact tokamak plasma with currents in modular Furth-Hartman type coils is investigated with respect to the impact on the magnetic field structure and to the ideal magnetohydrodynamic stability. A sequence of configurations, in which the current in the helical coils is increased up to the level of that of the main toroidal coils, is generated. The magnetic field structure acquires a ripple along the field lines when the currents in both sets of coils becomes comparable. The magn

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The prediction of the thermal energy confinement time, tau(th), for ITER size experiments is based on power law scalings obtained using data sets of present tokamak results in specific regimes, the most relevant being the ELMy H mode regime. A thorough statistical approach has provided a bust fit to these data with an estimation of the error bars which forms the basis for the ITER EDA design parameters. In this article the range of variation of the main parameters in the database are studied individually an

We present a systematic study of the oscillator strength of the positively charged excitons (X+) in Cd1-xMnxTe quantum wells. CW-absorption and time-resolved photoluminescence measurements were combined as two approaches for the determination of the oscillator strength. By varying (in a small magnetic field) the spin subband hole distribution at constant total concentration, we observe an increase of the oscillator strength in absorption, proportional to the hole concentration in one spin subband (the one w

Temperature-Dependence of Critical Currents in Superconducting Bi-2212/Ag Wires

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Beam-cavity interactions in high power cyclotrons

Sensitivity Enhancement in 1D Heteronuclear NMR Spectroscopy via Single-Scan Inverse Experiments

Long-range transport of magnetic microbeads using simple planar coils placed in a uniform magnetostatic field

The field-induced soliton phase of CuGeO3

The remarkable difference between surface and step atoms in the magnetic anisotropy of two-dimensional nanostructures

Piezoelectric anisotropy-phase transition relations in perovskite single crystals

On the enhancement of radiated electric and magnetic fields associated with lightning return strokes to tall structures

Evidence for the role of magnetic entropy and turbulent equipartition in stationary Ohmic tokamak discharges

Effect of helical coils on the magnetic field and the stability of a compact toroidal plasma

Losses in HTS Tapes due to AC External Magnetic Field and AC Transport Current

Considerations on energy confinement time scalings using present tokamak databases and prediction for ITER size experiments

Oscillator strengths of charged excitons: combining magnetoabsorption and photoluminescence dynamics in semimagnetic quantum wells