Interaction Of Energetic Particles Research Articles

Interaction of energetic particles with HM-waves in the magnetosphere

Energetic particle response in electromagnetic fields of ULF HM-waves in the magnetosphere is reviewed. Pc4–5 geomagnetic pulsations observed at the synchronous altitude are classified into three types, in respect to their major magnetic field polarization in different directions, local time dependence, and different characteristics of accompanied flux modulations of energetic particles, i.e., two nearly transverse waves with the azimuthal and the radial polarization, and the compressional stormtime pulsations. Firstly, we formulate the drift kinetic theory of particle flux modulations under the constraint of the magnetic moment conservation. A generalized energy integral of the particle motion interacting with a ULF-wave with the three-dimensional structure propagating to the azimuthal direction is obtained in the L-shell coordinate of a mirror magnetic field. Its linearized form is reduced to the same form as the previously derived energy change, including the bounce-drift resonant interaction. It is shown that the perturbed guiding center distribution function of energetic particles consists of four contributions, the adiabatic mirror effect corresponding to pitch-angle change, the kinetic effects due to energy change and the accompanying L-shell displacement, and the bounceaveraged drift phase bunching. Secondly, the basic HM-wave modes constitutingcoupling ULF oscillations in non-uniform plasmas are discussed in different models of approach for different plasma states. The diamagnetic drift Alfvén wave and the compressional drift wave with a larger azimuthal mode number in a high-beta plasma are candidates for the stormtimes pulsations. The former is intrinsically a guided localized mode, while the latter is a non-localized mode. By making use of the above preparation, we apply the developed drift kinetic theory to interpret the phase relationships between the ion flux modulation and the geomagnetic pulsation in some selected examples of observations, demonstrating a fair agreement in theoretical results with the observations.

Nuclear processes in the jets of SS 433

view Abstract Citations (22) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Nuclear processes in the jets of SS 433. Ramaty, R. ; Kozlovsky, B. ; Lingenfelter, R. E. Abstract The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS 433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg-asterisk and (16)O-asterisk in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS 433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations. Publication: The Astrophysical Journal Pub Date: August 1984 DOI: 10.1086/184322 Bibcode: 1984ApJ...283L..13R Keywords: Astrophysics; Gamma Ray Astronomy; Gamma Ray Bursts; Jets; Nuclear Astrophysics; Plasma Jets; Astronomical Models; Atomic Excitations; Energy Spectra; Particle Interactions; Astrophysics full text sources ADS | data products SIMBAD (1)

U.S. contributions to auroral aeronomy, 1979‐1982

Auroral aeronomy is the scientific discipline devoted to the study of the interaction of energetic particles and electric fields with the atmosphere of planets that have an appreciable intrinsic magnetic field. Specific topics that describe this interaction include: transport and energy degradation of energetic electrons and ions in a collision dominated medium, the excitation of atoms and molecules by collisions and by chemical reactions, the auroral spectrum, its production and interpretation, perturbations upon the ionospheric plasma in terms of enhanced ionization, composition, dynamics and heating, and perturbations upon the neutral atmosphere in terms of composition, dynamics and heating.It is not possible, however, to identify aeronomic processes as being uniquely relevant to the aurora because solar EUV photons and photoelectrons are subject to similar physical and chemical reactions leading to spectral emissions that also result from auroral electron bombardment of the atmosphere. Thus, a large segment of aeronomic research carried out during the quadrennium is reviewed in companion articles of this report to the I.U.G.G. An overview of Polar and Auroral Phenomena is presented by Reiff [1983, this issue]. She reviews auroral morphology, including pulsating aurora, emphasizing the relationship to magnetospheric phenomenology. Local and global characteristics of energetic particle precipitation are presented, and a summary of recent observations of energetic ions of ionospheric origin is given. Observations and theories on auroral electrodynamics are also reviewed by Reiff [1983], The effects of heating and ionization on Thermospheric Dynamics are reviewed by Roble [1983, this issue]. Progress in our understanding of the Neutral and Ion Composition of the Thermosphere is reported by Torr [1983, this issue]. This review focuses on reaction rate coefficients that are inferred from rockets and satellite observations of ion and neutral densities and optical emission rates, a technique that is particularly useful for studying metastable states of atmospheric gases. The chemical–ionic reactions pertinent to the dayglow are also relevant to the aurora so that progress in auroral aeronomy leans heavily on our understanding of the aeronomy at middle and low latitudes . Dynamical effects of auroral electric fields upon the high latitude ionosphere are discussed in the review by Richmond [1983, this issue]. The aurora and, in particular, the energetic solar proton events (SPE) significantly perturb the middle atmosphere, i.e. the mesosphere and upper stratosphere. Effects upon the chemistry and ionization are reviewed by Solomon [1983, this issue] while the dynamic and electrodynamic consequences are discussed, respectively, by Hartmann [1983, this issue] and by Kelly [1983, this issue].

The Interaction of Fast Particles with Frozen Gases in T Tau Nebulae: The Physical Background

The interaction of energetic particles with frozen gas layers plays a relevant role in a variety of astrophysical scenarii and also in T Tau nebulae because of the large fluxes of particles ejected by these stars during their continuous flaring activity and the observed presence of ice grains at least around the very young star KL Tau (Cohen, 1975).

Gamma-Ray Astronomy

Cosmic gamma rays, the physical processes responsible for their production and the astrophysical sites from which they were seen are reported. The bulk of the observed gamma ray emission is in the photon energy range from about 0.1 MeV to 1 GeV, where observations are carried out above the atmosphere. There are also, however, gamma ray observations at higher energies obtained by detecting the Cerenkov light produced by the high energy photons in the atmosphere. Gamma ray emission was observed from sources as close as the Sun and the Moon and as distant as the quasar 3C273, as well as from various other galactic and extragalactic sites. The radiation processes also range from the well understood, e.g. energetic particle interactions with matter, to the still incompletely researched, such as radiation transfer in optically thick electron positron plasmas in intense neutron star magnetic fields.

Nuclear gamma-rays from energetic particle interactions

view Abstract Citations (268) References (118) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Nuclear gamma-rays from energetic particle interactions. Ramaty, R. ; Kozlovsky, B. ; Lingenfelter, R. E. Abstract Gamma-ray line emission due to nuclear deexcitation following energetic particle interactions with abundant constituents of cosmic matter is studied. Reactions induced by energetic protons and alpha particles in ambient nuclei (He, C, N, O, Ne, Mg, Al, Si, S, Ca, and Fe) are considered, along with inverse reactions in which energetic nuclei interact with ambient H and He. Line-production cross sections are evaluated by analyzing a large body of laboratory nuclear data. Both prompt gamma rays, produced by direct excitation of nuclear levels and by spallation reactions that leave the secondary nucleus in an excited state, and delayed emission from long-lived radioactive nuclei also produced in the energetic particle reactions are investigated. A line list is provided, and the shapes of the gamma-ray lines are determined. Gamma-ray line production in the interstellar medium is evaluated in detail. Publication: The Astrophysical Journal Supplement Series Pub Date: July 1979 DOI: 10.1086/190596 Bibcode: 1979ApJS...40..487R Keywords: Energetic Particles; Gamma Ray Astronomy; Nuclear Reactions; Particle Interactions; Astronomical Spectroscopy; Cross Sections; Gamma Ray Spectra; Interstellar Matter; Line Spectra; Photons; Protons; Solar Radiation; Space Radiation; Galactic Center:Gamma Rays; Gamma Rays:Interstellar Matter; Gamma Rays:Nuclear Reactions full text sources ADS |

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Interaction of Energetic Nuclear Particles in Space with the Lunar Surface

Interaction of Energetic Nuclear Particles in Space with the Lunar Surface

Non-relativistic solar electrons

This review summarizes both the direct spacecraft observations of non-relativistic solar electrons, and observations of the X-ray and radio emission generated by these particles at the Sun and in the interplanetary medium. These observations bear on three physical processes basic to energetic particle phenomena: (1) the acceleration of particles in tenuous plasmas; (2) the propagation of energetic charged particles in a disordered magnetic field, and (3) the interaction of energetic charged particles with tenuous plasmas to produce electromagnetic radiation. Because these electrons are frequently accelerated and emitted by the Sun, mostly in small and relatively simple flares, it is possible to define a detailed physical picture of these processes. In many small solar flares non-relativistic electrons accelerated during flash phase constitute the bulk of the total flare energy. Thus the basic flare mechanism in these flares essentially converts the available flare energy into fast electrons. Non-relativistic electrons exhibit a wide variety of propagation modes in the interplanetary medium, ranging from diffusive to essentially scatter-free. This variability in the propagation may be explained in terms of the distribution of interplanetary magnetic field fluctuations. Type III solar radio burst emission is generated by these electrons as they travel out to 1 AU and beyond. Recent in situ observations of these electrons at 1 AU, accompanied by simultaneous observations of the low frequency radio emission generated by them at 1 AU provide quantitative information on the plasma processes involved in the generation of type III bursts.

Concerning the use of dE/dx systems to measure the charge and energy of relativistic particles

A Monte Carlo program has been used to optimize the method of selectively averaging the pulse heights of a system of identical, specific energy loss detectors. The program simulated the interaction of energetic heavy charged particles whose specific energy losses were subject to Landau fluctuations. Distributions resulting from averaging the lowest 50% of the outputs from two to fourteen detectors are tabulated. In addition, a method which can measure the charge and energy of relativistic particles by using two d E/d x systems is described.

Nato Advanced study institute of interaction of energetic charged particles with Solids, Robert College, Istanbul, Turkey.

Nato Advanced study institute of interaction of energetic charged particles with Solids, Robert College, Istanbul, Turkey.

NATO advanced study institute on interaction of energetic charged particles with solids

NATO advanced study institute on interaction of energetic charged particles with solids

NATO advanced study institute on interaction of energetic charged particles with solids

NATO advanced study institute on interaction of energetic charged particles with solids

Anisotropic Effects in Interactions of Energetic Charged Particles in a Crystal Lattice

Anisotropic Effects in Interactions of Energetic Charged Particles in a Crystal Lattice

The bubble chamber and mechanism of bubble growth

Although the bubble chamber was only invented byGlaser in 1952, there are today over a hundred chambers in use in physics laboratories throughout the world. In the field of high energy physics they have proved to be an invaluable tool and already much information has been obtained concerning very energetic particle interactions and properties of «strange» particles by the use of both hydrocarbon and liquid hydrogen chambers.