Determination of the Coronal and Interplanetary Magnetic-Field Strength and Radial Profiles from the Large-Scale Photospheric Magnetic Fields

A new model has been proposed for magnetic field determination at different distances from the Sun during different solar cycle phases. The model depends on the observed large-scale non-polar photospheric magnetic fields and that measured at polar regions from 55N to 90N and from 55S to 90S,which are the visible manifestations of cyclic changes in the toroidal and poloidal components of the global magnetic field of the Sun. The modeled magnetic field is determined as the superposition of the non-polar and the polar photospheric magnetic field cycle variations. The agreement between the model predictions and magnetic fields derived from direct, in-situ, measurements at different distances from the Sun, obtained by different methods, and at different solar activity phases is quite satisfactory. From a comparison of the magnetic fields as observed and as calculated from the model at 1 AU, it should be concluded that the model magnetic-field variations adequately explains the major features of the IMF Bx component cycle evolution at the Earth's orbit. The model CR-averaged magnetic fields correlate with CR-averaged IMF Bx component at the Earth's orbit with a coefficient of 0.688, and for seven CR-averaged data the correlation reaches 0.808. The model magnetic-field radial profiles were compared with that of the already existing models. In addition, the decrease in the non-polar and polar photospheric magnetic fields has been revealed. Both magnetic fields during solar cycle maxima and that during minima phases decreased from Cycle 21 to Cycle 24. It means that both the toroidal and poloidal components and therefore, the solar global magnetic field decreased from Cycle 21 to Cycle 24.Comment: 27 pages, 6 figures, 2 table

Dynamics of platicons due to third-order dispersion

Dynamics of platicons caused by the third-order dispersion is studied. It is shown that under the influence of the third-order dispersion platicons obtain angular velocity depending both on dispersion and on detuning value. A method of tuning of platicon associated optical frequency comb repetition rate is proposed.Comment: 11 pages, 5 figure

Impact ionization fronts in Si diodes: Numerical evidence of superfast propagation due to nonlocalized preionization

We present numerical evidence of a novel propagation mode for superfast impact ionization fronts in high-voltage Si $p^+$-$n$-$n^+$ structures. In nonlinear dynamics terms, this mode corresponds to a pulled front propagating into an unstable state in the regime of nonlocalized initial conditions. Before the front starts to travel, field-ehanced emission of electrons from deep-level impurities preionizes initially depleted $n$ base creating spatially nonuniform free carriers profile. Impact ionization takes place in the whole high-field region. We find two ionizing fronts that propagate in opposite directions with velocities up to 10 times higher than the saturated drift velocity.Comment: 3 pages, 4 figure

To the practical design of the optical lever intracavity topology of gravitational-wave detectors

The QND intracavity topologies of gravitational-wave detectors proposed several years ago allow, in principle, to obtain sensitivity significantly better than the Standard Quantum Limit using relatively small anount of optical pumping power. In this article we consider an improved more ``practical'' version of the optical lever intracavity scheme. It differs from the original version by the symmetry which allows to suppress influence of the input light amplitude fluctuation. In addition, it provides the means to inject optical pumping inside the scheme without increase of optical losses. We consider also sensitivity limitations imposed by the local meter which is the key element of the intracavity topologies. Two variants of the local meter are analyzed, which are based on the spectral variation measurement and on the Discrete Sampling Variation Measurement, correspondingly. The former one, while can not be considered as a candidate for a practical implementation, allows, in principle, to obtain the best sensitivity and thus can be considered as an ideal ``asymptotic case'' for all other schemes. The DSVM-based local meter can be considered as a realistic scheme but its sensitivity, unfortunately, is by far not so good just due to a couple of peculiar numeric factors specific for this scheme. From our point of view search of new methods of mechanical QND measurements probably based on improved DSVM scheme or which combine the local meter with the pondermotive squeezing technique, is necessary.Comment: 27 pages, 6 figure

Soliton dual comb in crystalline microresonators

We present a novel compact dual-comb source based on a monolithic optical crystalline MgF$_2$ multi-resonator stack. The coherent soliton combs generated in two microresonators of the stack with the repetition rate of 12.1 GHz and difference of 1.62 MHz provided after heterodyning a 300 MHz wide radio-frequency comb. Analogous system can be used for dual-comb spectroscopy, coherent LIDAR applications and massively parallel optical communications.Comment: 5 pages, 5 figure