Electron energy probability function and L-p similarity in low pressure inductively coupled bounded plasma

Particle-In-Cell (PIC) simulations are carried out to investigate the effect of discharge length (L) and pressure (p) on Electron Energy Probability Function (EEPF) in a low pressure radio frequency (rf) inductively coupled plasma (ICP) at 13.56 MHz. It is found that for both cases of varying L (0.1–0.5 m) and p (1–10 mTorr), the EEPF is a bi-Maxwellian with a step in the bounded direction (x) and non-Maxwellian with a hot tail in the symmetric unbounded directions (y, z). The plasma space potential decreases with increase in both L and p, the trapped electrons having energies in the range 0–20 eV. In a conventional discharge bounded in all directions, we infer that L and p are similarity parameters for low energy electrons trapped in the bulk plasma that have energies below the plasma space potential (eVp). The simulation results are consistent with a particle balance model

On the cosmic ray bound for models of extragalactic neutrino production

We obtain the maximum diffuse neutrino intensity predicted by hadronic photoproduction models of the type which have been applied to the jets of active galactic nuclei or gamma ray bursts. For this, we compare the proton and gamma ray fluxes associated with hadronic photoproduction in extragalactic neutrino sources with the present experimental upper limit on cosmic ray protons and the extragalactic gamma ray background, employing a transport calculation of energetic protons traversing cosmic photon backgrounds. We take into account the effects of the photon spectral shape in the sources on the photoproduction process, cosmological source evolution, the optical depth for cosmic ray ejection, and discuss the possible effects of magnetic fields in the vicinity of the sources. For photohadronic neutrino sources which are optically thin to the emission of neutrons we find that the cosmic ray flux imposes a stronger bound than the extragalactic gamma ray background in the energy range between 10^5 GeV and 10^11 GeV, as previously noted by Waxman & Bahcall (1999). We also determine the maximum contribution from the jets of active galactic nuclei, using constraints set to their neutron opacity by gamma-ray observations. This present upper limit is consistent with the jets of active galactic nuclei producing the extragalactic gamma ray background hadronically, but we point out future observations in the GeV-to-TeV regime could lower this limit. We also briefly discuss the contribution of gamma ray bursts to ultra-high energy cosmic rays as it can be inferred from possible observations or limits on their correlated neutrino fluxes.Comment: 16 pages, includes 7 figures, using REVtex3.1, accepted for publication in Phys.Rev.D after minor revision

Constance mirror program: Progress and plans

The current state of the mechanics of the Constance II experiment, the physics results gathered, the motivation background, and future plans for the Constance II experiment are reviewed. Several improvements have been made and several experimental investigations have been completed. These include the construction/installation/testing of: (1) liquid-nitrogen cooled, Ioffe bars installed, (2) a diverter coil (3) the 100 kW ICRF generator, (4) the data acquisition system, and (5) the optimum hot-iron operation of the machine with Titanium and pulsed-gas plasma guns. Measurements were made of the density, temperature, and radius of the plasma. Ion-cyclotron fluctuations were observed, their bandwidth measured, and data collected demonstrating resonance heating. New X-ray diagnostics were designed and purchased, and progress on the Thomson scattering was made. Finally, a new hot cathode gun was designed and constructed

Atoms of None of the Elements Ionize While Atoms of Inert Behavior Split by Photonic Current

As studied, atoms deal with the positive or negative charge by losing or gaining an electron. However, the gaseous and solid atoms can execute interstate electron dynamics. They can also deal with transition states. Solid atoms can elongate from the east-west poles at the ground surface level. Under suitable energy, solid atoms can expand, and gaseous atoms can contract. When the excessive field is intact, flowing inert gas atoms can split. The splitting inert gas atoms convert into electron streams. Those electron streams carrying the photons when impinging on the naturally-elongated solid atoms, further elongation of the atoms takes place. If not, elongated atoms at least deform. Gaseous atoms can squeeze by the suffering of their lattices. Such behaviors of the atoms validate that they cannot ionize. On splitting the flowing inert gas atoms, characteristics of the photons become apparent. Those photons that are not carried by the electron streams can enter the air medium directly. On traveling photons in the air medium, their energy dissipates in heat, and their force confines in the form of a field. On confinement of the field of traveling photons with the field of air-medium, a glow of light is appeared, which is better known in plasma. The splitting of inert gas atoms, the carrying of photons by the electron streams, and the lighting of traveling photons validate that an electric current is photonic. In various microscopes, the magnification of an image is based on the resolving power of photons. Photonic current is due to the propagation of the photons in the structure of the interstate electron gap. Some well-known principles are also discussed, validating that an electric current is a photonic current. Indeed, this study brings about profound changes in science

The sounds of the Little and Big Bangs

Studies of heavy ion collisions have discovered that tiny fireballs of new phase of matter -- quark gluon plasma (QGP) -- undergoes explosion, called the Little Bang. In spite of its small size, it is not only well described by hydrodynamics, but even small perturbations on top of the explosion turned to be well described by hydrodynamical sound modes. The cosmological Big Bang also went through phase transitions, the QCD and electroweak ones, which are expected to produce sounds as well. We discuss their subsequent evolution and hypothetical inverse acoustic cascade, amplifying the amplitude. Ultimately, collision of two sound waves leads to formation of gravity waves, with the smallest wavelength. We briefly discuss how those can be detected.Comment: This paper is a short semi-popular review describing some recent developments in two very different fields, united by some common physics. It was written for the Universe journa