Decanaling of high-energy particles from planar channels of crystal. Elastic and inelastic scattering processes

2020 ◽  
Vol 5 ◽  
pp. 5-10
Author(s):  
Yu.A. Kashlev ◽  
◽  
S.A. Maslyaev ◽  
Keyword(s):  
Inelastic Scattering ◽  
Rate Coefficient ◽  
Particle Beam ◽  
High Energy ◽  
Confluent Hypergeometric Function ◽  
Point Of View ◽  
Directional Motion ◽  
High Energy Particles ◽  
Motion Mode ◽  
Fast Charged Particle

Based on the principles of nonequilibrium statistical thermodynamics, the kinetic theory of de-channeling of high-energy particles from planar channels of a crystal have been deduced. The de-channeling rate coefficient is considered from the point of view of the transition of a fast particle from the directional motion mode to the state of chaotic motion. The corresponding equation have been obtained that takes into account both the coherent nature of the diffraction of a particle beam in a regular single crystal and the inelastic scattering of channeled particles by electrons and phonons. An analytical solution of this equation have been obtained on the class of confluent hypergeometric function using which the de-channeling rate constant Re have been calculated. It have been shown that up to second-order terms in terms of the interaction potential the constant Re is inversely proportional to the relaxation time of the system tph. In calculating tph the polarization of space by a fast charged particle is not taken into account. The temperature and isotopic dependences of the de-channeling rate have been obtained.

scholarly journals Ionospheric accelerator

1989 ◽  
Vol 7 (3) ◽  
pp. 637-643
Author(s):  
T. Tajima ◽  
W. Horton ◽  
S. Nishikawa ◽  
T. Nishikawa
Keyword(s):  
Electromagnetic Waves ◽  
Pulse Propagation ◽  
Particle Beam ◽  
High Energy ◽  
Threshold Power ◽  
Binding Property ◽  
Beam Transport ◽  
Power Pulse ◽  
Induced Transparency ◽  
High Energy Particles

Ionospheric acceleration of high energy particles by a short wavelength microwave pulse is discussed. The intense electromagnetic waves in an ionospheric (F2) or magnetospheric plasma can be self-trapped above a threshold power. The self-binding property and the consequent self-induced transparency of the triple soliton structure of two electromagnetic waves and a plasma wave allow the propagation of an intense electromagnetic pulse without the severe and wasteful distortion that accompanies low power pulse propagation. The effects of magnetospheric fluctuations on the particle beam transport are considered. The fluctuation-induced transport seems to be within the margin of tolerance for useful beam transport. Orbits of negatively charged particles are stable. While synchrotron radiation loss for electrons is prohibitive, that of muons and antiprotons is negligible. A corresponding terrestrial application is also suggested.

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

Observation of High-Energy Particles in the Inner Radiation Belt by the HEP Instrument of the Arase Satellite

2020 ◽  
Vol 18 (6) ◽  
pp. 398-403
Author(s):  
Honoka TODA ◽  
Wataru MIYAKE ◽  
Takefumi MITANI ◽  
Takeshi TAKASHIMA ◽  
Yoshizumi MIYOSHI ◽  
...  
Keyword(s):  
Radiation Belt ◽  
High Energy ◽  
High Energy Particles

scholarly journals Gamma-Ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Yoshiyuki Inoue ◽  
Dmitry Khangulyan ◽  
Akihiro Doi
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Thermal Activity ◽  
X Ray ◽  
Cascade Models ◽  
Coronal Activity ◽  
Ngc 1068 ◽  
High Energy Particles

To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the existence of weak non-thermal coronal activity. In addition, the IceCube collaboration reported NGC 1068, a nearby Seyfert, as the hottest spot in their 10 yr survey. These pieces of evidence are enough to investigate the non-thermal perspective of AGN coronae in depth again. This article summarizes our current observational understanding of AGN coronae and describes how AGN coronae generate high-energy particles. We also provide ways to test the AGN corona model with radio, X-ray, MeV gamma ray, and high-energy neutrino observations.

scholarly journals Saturation effects in SIDIS at very forward rapidities

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
E. Iancu ◽  
A. H. Mueller ◽  
D. N. Triantafyllopoulos ◽  
S. Y. Wei
Keyword(s):  
Inelastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Virtual Photon ◽  
Large Fraction ◽  
Quark Distribution ◽  
High Energy ◽  
Longitudinal Momentum ◽  
Black Disk ◽  
Gluon Saturation

Abstract Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.

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