A statistical study of gyro-averaging effects in a reduced model of drift-wave transport [electronic resource].

Imprint
Washington, D.C. : United States. Dept. of Energy. Office of Science ; Oak Ridge, Tenn. : distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2016
Physical description
1 online resource (p. 082308) : digital, PDF file.

Online

Available online

Description

Contents/Summary

Summary
Here, a statistical study of finite Larmor radius (FLR) effects on transport driven by electrostatic driftwaves is presented. The study is based on a reduced discrete Hamiltonian dynamical system known as the gyro-averaged standard map (GSM). In this system, FLR effects are incorporated through the gyro-averaging of a simplified weak-turbulence model of electrostatic fluctuations. Formally, the GSM is a modified version of the standard map in which the perturbation amplitude, K0, becomes K0J0($\hat{p}$), where J0 is the zeroth-order Bessel function and $\hat{p}$ s the Larmor radius. Assuming a Maxwellian probability density function (pdf) for $\hat{p}$ , we compute analytically and numerically the pdf and the cumulative distribution function of the effective drift-wave perturba- tion amplitude K0J0($\hat{p}$). Using these results, we compute the probability of loss of confinement (i.e., global chaos), Pc provides an upper bound for the escape rate, and that Pt rovides a good estimate of the particle trapping rate. Lastly. the analytical results are compared with direct numerical Monte-Carlo simulations of particle transport.

Subjects

Subjects
Engineering.

Bibliographic information

Publication date
2016
Note
Published through SciTech Connect.
08/25/2016.
"AT1030100"
"ERAT021"
Physics of Plasmas 23 8 ISSN 1070-664X AM
Julio Fonseca; Diego B. Del-Castillo-Negrete; Igor M. Sokolov; Ibere L. Caldas.
Funding information
AC05-00OR22725
Librarian view | Catkey: 12161349