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Classical collisions with an ideal gas generate non-Maxwellian distribution functions for a single ion in a radio frequency ion trap. The distributions have power-law tails whose exponent depends on the ratio of buffer gas to ion mass. This…

Atomic Physics · Physics 2009-11-13 Ralph G. Devoe

At impact energies $ \stackrel{>}{\sim}1$ GeV/u the projectile-electron excitation and loss occurring in collisions between highly charged ions and neutral atoms is already strongly influenced by the presence of atomic electrons. In order…

Atomic Physics · Physics 2015-05-18 A. B. Voitkiv , B. Najjari , S. P. Shevelko

We find the probability density function $\mathcal{P}(V_{\texttt{r}})$ of the relativistic relative velocity for two colliding particles in a non-degenerate relativistic gas. The distribution reduces to Maxwell distribution for the relative…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-02 M. Cannoni

The single-ionization rate coefficient of a plasma neutral depends both on the microscopic electron-impact cross section and on the macroscopic shape of the electron energy distribution function (EEDF). We present a reproducible benchmark…

General Physics · Physics 2026-05-06 Abdelmalek Boumali

An ion in a radiofrequency (rf) trap sympathetically cooled by a simultaneously trapped neutral buffer gas exhibits deviations from thermal statistics caused by collision-induced coupling of the rf field to the ion motion. For a uniform…

Atomic Physics · Physics 2019-10-23 I. Rouse , S. Willitsch

Complete and physically adequate analytical and semi-analytical solutions have been obtained using a practical dimensionless form of kinetic equation assuming azimuthal symmetry and Maxwellian distributions of target plasma species.…

Plasma Physics · Physics 2010-11-22 P. R. Goncharov

Elliptic flow in heavy-ion collisions at incident energies $E_{lab}\simeq$ (1--160)A GeV is analyzed within the model of 3-fluid dynamics (3FD). We show that a simple correction factor, taking into account dissipative affects, allows us to…

Nuclear Theory · Physics 2009-12-30 Yu. B. Ivanov , I. N. Mishustin , V. N. Russkikh , L. M. Satarov

Although the convergent close-coupling (CCC) method has achieved unprecedented success in obtaining accurate theoretical cross sections for electron-atom scattering, it generally fails to yield converged energy distributions for ionization.…

Atomic Physics · Physics 2007-05-23 S. Jones , A. T. Stelbovics

Hadron yields in high energy heavy ion collisions have been fitted and reproduced by thermal models using standard statistical distributions. These models give insight into the freeze-out conditions at varying beam energies. In this paper…

High Energy Physics - Phenomenology · Physics 2010-01-15 J. Cleymans , G. Hamar , P. Levai , S. Wheaton

We present atomic-scale computer simulations in equiatomic L1$_0$-CoPt where Molecular Dynamics and Monte Carlo techniques have both been applied to study the vacancy-atom exchange and kinetics relaxation. The atomic potential is determined…

Materials Science · Physics 2009-11-11 M. Allalen , H. Bouzar , T. Mehaddene

Collisionless magnetic reconnection is a prime candidate to account for flare-like or steady emission, outflow launching, or plasma heating, in a variety of high-energy astrophysical objects, including ones with relativistic ion-electron…

High Energy Astrophysical Phenomena · Physics 2014-11-05 Mickaël Melzani , Rolf Walder , Doris Folini , Christophe Winisdoerffer , Jean M. Favre

A theory is developed for the evolution of the non-equilibrium distribution of quasiparticles when the scattering rate decreases due to particle collisions. We propose a "modified one-collision approximation" which is most effective for…

Disordered Systems and Neural Networks · Physics 2009-11-10 R. N. Gurzhi , A. I. Kopeliovich , A. N. Kalinenko , A. V. Yanovsky , E. N. Bogachek , Uzi Landman , H. Buhmann , L. W. Molenkamp

Using the Mott exact cross section for moderate relativistic energies, we calculated the corrections to the first-order Born higher moments of the energy-loss distribution of charged particles in a wide range of the particle charge numbers.

High Energy Physics - Phenomenology · Physics 2020-06-15 O. Voskresenskaya

A one-dimensional Vlasov-Poisson system is considered to elucidate how the information entropies of the probability distribution functions of the electron position and velocity variables evolve in the Landau damping process. Considering the…

Plasma Physics · Physics 2024-10-14 K. Maekaku , H. Sugama , T. -H. Watanabe

We develop a stochastic approximation-type algorithm to solve finite state/action, infinite-horizon, risk-aware Markov decision processes. Our algorithm has two loops. The inner loop computes the risk by solving a stochastic saddle-point…

Optimization and Control · Mathematics 2019-12-05 Wenjie Huang , William B. Haskell

The quasistatic limit of the velocity-gauge strong-field approximation describing the ionization rate of atomic or molecular systems exposed to linear polarized laser fields is derived. It is shown that in the low-frequency limit the…

Atomic Physics · Physics 2007-05-23 Yulian V. Vanne Alejandro Saenz

A major approach to saddle point optimization $\min_x\max_y f(x, y)$ is a gradient based approach as is popularized by generative adversarial networks (GANs). In contrast, we analyze an alternative approach relying only on an oracle that…

Optimization and Control · Mathematics 2021-04-02 Youhei Akimoto

Energy loss of energetic ions in solid is crucial in many field, and accurate prediction of the ion stopping power is a long-time goal. Though great efforts have been made, it is still very difficult to find a universal prediction model to…

Applied Physics · Physics 2020-10-21 Xun Guo , Hao Wang , Shijun Zhao , Ke Jin , Jianming Xue

Although partition temperature derived using the Darwin-Fowler method is exact for simple scenarios, the derivation for complex systems might reside on specific approximations whose viability is not ensured if the thermodynamic limit is not…

Nuclear Theory · Physics 2023-11-09 Wei-Liang Qian , Kai Lin , Rui-Hong Yue , Yogiro Hama , Takeshi Kodama

The ionization loss of a high-energy electron-positron pair in thin targets is considered. The analogue of the Landau distribution function is derived for this loss under the condition when the Chudakov effect of the pair ionization loss…

Accelerator Physics · Physics 2023-02-01 S. V. Trofymenko