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At least 19 recordsLinked to original sources
arXiv2007

Deflection of High-Energy Cosmic Radiation Ions using a Bent Crystal Shield

A bent crystal shield which is capable of deflecting cosmic radiation ions of all atomic numbers away from spacecraft using the ion channeling effect is described. Its effect on the transmitted angular distribution of heavy, high-energy ions is characterized using Monte Carlo channeling simulations. Ions up to an energy limit set by the bent crystal curvature radius are deflected by the full curvature angle. A bent crystal shield with a 1 x 1 cm2 surface area capable of deflecting such ions with energies up to 100 GeV/nucleon is fabricated in which the lattice planes across the entrance surface are uniformly aligned.

astro-ph↗
arXiv2007

Nuclear Georeactor Generation of Earth's Geomagnetic Field

The purpose of this communication is to suggest that the mechanism for generating the geomagnetic field and the energy source for powering it are one and the same, a nuclear georeactor at the center of the Earth. Toward this end, I: i) Present evidence that the nuclear georeactor fission-product sub-shell is fluid; ii)Suggest that the geomagnetic field is generated within the georeactor sub-shell, rather than within Earth's iron-alloy fluid core; iii) Describe why convection appears more feasible within the georeactor sub-shell than within the iron-alloy core; iv) Disclose additional relative physical advantages for georeactor sub-shell dynamo operation; and, v) Outline briefly the research that should be conducted to advance the state of knowledge of georeactor-geomagnetic field generation. The concept of geomagnetic field production by the nuclear georeactor is presented specifically for the Earth. The concepts and principles, however, are generally applicable to planetary magnetic field production.

physics.geo-ph↗
arXiv2008

Quantum Signatures of Solar System Dynamics

Let w(i) be a period of rotation of the i-th planet around the Sun (or w(j;i) be a period of rotation of j-th satellite around the i-th planet). From empirical observations it is known that the sum of n(i)w(i)=0 (or the sum of n(j)w(j;i)=0) for some integers n(i) (or n(j)), different for different satellite systems. These conditions, known as resonance conditions, make uses of theories such as KAM difficult to implement. The resonances in Solar System are similar to those encountered in old quantum mechanics where applications of methods of celestial mechanics to atomic and molecular physics were highly sucsessful. With such a success, the birth of new quantum mechanics is difficult to understand. In short, the rationale for its birth lies in simplicity with which the same type of calculations are done using new methods capable of taking care of resonances. The solution of quantization puzzle was found by Heisenberg. In this paper new uses of Heisenberg's ideas are found. When superimposed with the equivalence principle of general relativity, they lead to quantum mechanical tratment of observed resonances in Solar System. To test correctness of our theoretical predictions the number of allowed stable orbits for planets and for equatorial stable orbits of satellites of heavy planets is calculated resulting in good agreement with observational data. In addition, the paper briefly discusses quantum mechanical nature of rings of heavy planets and potential usefulness of the obtained results for cosmology.

physics.gen-ph↗
arXiv2007

Magnetic Field Generation in Planets and Satellites by Natural Nuclear Fission Reactors

One of the most fundamental problems in physics has been to understand the nature of the mechanism that generates the geomagnetic field and the magnetic fields of other planets and satellites. For decades, the dynamo mechanism, thought to be responsible for generating the geomagnetic field and other planetary magnetic fields, has been ascribed to convection in each planet's iron-alloy core. Recently, I described the problems inherent in Earth-core convection and proposed instead that the geomagnetic field is produced by a dynamo mechanism involving convection, not in the fluid core, but in the electrically conductive, fluid, fission-product sub-shell of a natural nuclear fission reactor at the center of the Earth, called the georeactor. Here I set forth in detail the commonality in the Solar System of the matter like that of the inside of the Earth, which is my basis for generalizing the concept of planetary magnetic field generation by natural planetocentric nuclear fission reactors.

physics.geo-ph↗
arXiv2009

Orbit determination for next generation space clocks

Over the last decade of the 20th century and the first few years of the 21st, the uncertainty of atomic clocks has decreased by about two orders of magnitude, passing from the low 10^-14 to below 10^-16, in relative frequency . Space applications in fundamental physics, geodesy, time/frequency metrology, navigation etc... are among the most promising for this new generation of clocks. Onboard terrestrial or solar system satellites, their exceptional frequency stability and accuracy makes them a prime tool to test the fundamental laws of nature, and to study gravitational potentials and their evolution. In this paper, we study in more detail the requirements on orbitography compatible with operation of next generation space clocks at the required uncertainty based on a completely relativistic model. Using the ACES (Atomic Clock Ensemble in Space) mission as an example, we show that the required accuracy goal can be reached with relatively modest constraints on the orbitography of the space clock, much less stringent than expected from "naive" estimates. Our results are generic to all space clocks and represent a significant step towards the generalised use of next generation space clocks in fundamental physics, geodesy, and time/frequency metrology.

physics.space-ph↗
arXiv2007

Deep-space laser-ranging missions ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) and ASTROD I for astrodynamics and astrometry

Deep-space laser ranging will be ideal for testing relativistic gravity, and mapping the solar-system to an unprecedented accuracy. ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) and ASTROD I are such missions. ASTROD I is a mission with a single spacecraft; it is the first step of ASTROD with 3 spacecraft. In this talk, after a brief review of ASTROD and ASTROD I, we concentrate of the precision of solar astrodynamics that can be achieved together with implications on astrometry and reference frame transformations. The precision planetary ephemeris derived from these missions together with second post-Newtonian test of relativistic gravity will serve as a foundation for future precise astrometry observations. Relativistic frameworks are discussed from these considerations.

astro-ph↗
arXiv2007

A few remarks about the Pioneer anomaly

Some features of the Pioneer anomaly are discussed in context of author's explanation of this effect as a deceleration of the probes in the graviton background. It is noted that if the model is true then the best parameter of the anomalous acceleration should be not the distance to the Sun but a cosine of the angle between a velocity of the probe and its radius-vector.

physics.gen-ph↗
arXiv2008

Physics of Atmospheric Electric Discharges in Gases: An Informal Introduction

A short account of the physics of electrical discharges in gases is given in view of its historical evolution and application to planetary atmospheres. As such it serves as an introduction to the articles on particular aspects of electric discharges contained in this book, in particular in the chapters on lightning and the violent discharges which in the recent two decades have been observed to take place in Earth's upper atmosphere. In addition of briefly reviewing the early history of gas discharge physics we discuss the main parameters affecting violent atmospheric discharges like collision frequency, mean free path and critical electric field strength. Any discharge current in the atmosphere is clearly carried only by electrons. Above the lower bound of the mesosphere the electrons must be considered magnetized with the conductivity becoming a tensor. Moreover, the collisional mean free path in the upper atmosphere becomes relatively large which lowers the critical electric field there and more easily enables discharges than at lower altitudes. Finally we briefly mention the relation of such discharges as sources for wave emission.

physics.space-ph↗
arXiv2008

Constraining MOND with Solar System dynamics

In this letter we investigate the deep Newtonian regime of the MOND paradigm from a purely phenomenological point of view by exploiting the least-square estimated corrections to the secular rates of the perihelia of the inner and of some of the outer planets of the Solar System by E.V. Pitjeva with the EPM2004 ephemerides. By using $μ(x)\approx 1-k_0(1/x)^n$ for the interpolating MONDian function, and by assuming that $k_0$, considered body-independent so to avoid violations of the equivalence principle, experiences no spatial variations throughout the Solar System we tightly constrain $n$ with the ratios of the perihelion precessions for different pairs of planets. We find that the range $1\leq n\leq 2$ is neatly excluded at much more than $3-σ$ level. Such a test would greatly benefit from the use of extra-precessions of perihelia independently estimated by other groups as well.

gr-qc↗
arXiv2008

Deformation of electron holes in phase space as prerequisite for narrow band maser emission: A qualitative discussion

A qualitative discussion is given of the role electron holes play in generating fine structure on the electron cyclotron maser radiation. It is argued that electron holes become deformed in phase space when interacting with an incomplete ring or horseshoe distribution which occurs in the presence of strong field aligned electric fields in the upward current region and in the presence of a loss cone. This interaction is based on momentum balance considerations. Deformed narrow electron holes cause steep velocity space gradients on the ring distribution that lead to intense but narrow band emission from their high speed sides and absorption at slightly higher frequency from their low speed sides. The twins of banded emission and absorption move in frequency space due to the average real space displacement of the deformed electron hole.

physics.space-ph↗
arXiv2008

GEANT4 and CREME96 comparison using only proton fluxes

CREME96 and GEANT4 are two well known particle transport codes through matter in space science. We present a comparison between the proton fluxes outgoing from an aluminium target, obtained by using both tools. The primary proton flux is obtained by CREME96 only, covering an energy range from MeV to hundreds GeV with the same result in both cases. We studied different thickness targets and two different GEANT4 physics lists in order to show how the spectra of the outgoing proton fluxes are modified. Our findings show consistent agreement of simulation data by each tool, with regards both GEANT4 physics lists and every thickness target analysed.

physics.comp-ph↗
arXiv2008

Application of afxy-code for parameterization of ionization yield function Y in the atmosphere for primary cosmic ray protons

In this work is obtained new approximation for the yield function Y for cosmic ray induced ionization in the Earth atmosphere on the basis of simulated data. The parameterization is obtained using inverse nonlinear problem solution with afxy(analyze fx=y)-code. Short description of the methods is given. The found approximation is for primary proton nuclei, inclined up to 70 degrees zenith angle. This permits to estimate the direct ionization by primary cosmic rays explicitly. The parameterization is applicable to the entire atmosphere, from ground level to upper atmosphere. Several implications of the found parameterization are discussed.

physics.space-ph↗
arXiv2010

Are Flyby Anomalies an ASTG Phenomenon?

This reading expounds with expediency on the recently proposed Azimuthally Symmetric Theory of Gravitation (ASTG) set-up earlier. At its inspection, it was demonstrated that the ASTG is capable (among others solar anomalies) of explaining the precession of the perihelion of solar planets. In the present, we show that the ASTG is capable of explaining the puzzling observations of flyby anomalies, i.e. the anomalous asymptotic speed increases of the osculating hyperbolic speed excess. It is shown that these flyby anomalies occur naturally in the ASTG. We derive the empirical formula proposed by Anderson et al. in 2008, which up to now has no physical or foundational basis except that experience suggest it. If the ASTG model is correct, then for the first time the Anderson et al. formula is given a physical meaning.

physics.gen-ph↗
arXiv2010

Unipolar Induction

The phenomenon of unipolar induction consists in generating electric field by uniformly rotating permanent magnets made of either conducting or dielectric substance. The origin of the field around conducting magnets is explained and calculated in Sect. 1. Dielectrics are considered in Sect. 2, where the role of the electric moment due to moving magnetic dipole moment is clarified. Sect. 3 is devoted to the description of the effect in the corotating frame of reference. In Sect. 4 the theory is applied to the Earth core and it is shown that the calculated electric field falls precisely into the range of the ambient electric field observed in the Tethered Satellite System mission of NASA. In the last paragraph I reflect on whether flyby anomaly might be attributed to an electric effect.

physics.gen-ph↗
arXiv2009

Canonical Electromagnetic Observables for Systematic Characterization of Electric and Magnetic Wave Field Data on board Spacecraft

We present a new characterization of partially coherent electric and magnetic wave vector fields.This characterization is based on the 36 auto/cross correlations of the 3+3 complex Cartesian components of the electric and magnetic wave fields and is particularly suited for analyzing electromagnetic wave data on board spacecraft. Data from spacecraft based electromagnetic wave instruments are usually processed as data arrays. These data arrays however do not have a physical interpretation in themselves; they are simply a convenient storage format. In contrast, the characterization proposed here contains exactly the same information but are in the form of manifestly covariant space-time tensors. We call this data format the Canonical Electromagnetic Observables (CEO) since they correspond to unique physical observables. Some of them are already known, such as energy density, Poynting flux, stress tensor, etc, while others should be relevant in future space research. As an example we use this formalism to analyze data from a chorus emission in the mid-latitude magnetosphere, as recorded by the STAFF-SA instrument on board the Cluster-II spacecraft.

physics.geo-ph↗
arXiv2008

Contrast Enhancement of Binary Star System Using an Optical Vortex Coronagraph

Using an optical vortex coronagraph and simple adaptive optics techniques we have made the first convincing demonstration of an optical vortex coronagraph that is coupled to a star gazing telescope. In particular we suppressed by 97% the primary star of a barely resolvable binary system, Cor Caroli, having an effective angular separation of only 1.4 lambda/D. The secondary star suffered no suppression.

physics.optics↗