scholarly journals Gravitational Contribution to the Heat Flux in a Simple Dilute Fluid: An Approach Based on General Relativistic Kinetic Theory to First Order in the Gradients

Entropy ◽  
2017 ◽  
Vol 19 (11) ◽  
pp. 537
Author(s):  
Dominique Brun-Battistini ◽  
Alfredo Sandoval-Villalbazo ◽  
Ana Garcia-Perciante
1976 ◽  
Vol 13 (10) ◽  
pp. 2724-2735 ◽  
Author(s):  
E. Asseo ◽  
D. Gerbal ◽  
J. Heyvaerts ◽  
M. Signore

2010 ◽  
Vol 165 (17-18) ◽  
pp. 1024-1028 ◽  
Author(s):  
A.L. García-Perciante ◽  
A. Sandoval-Villalbazo

1973 ◽  
Vol 14 (9) ◽  
pp. 1254-1257 ◽  
Author(s):  
R. Berezdivin ◽  
R. K. Sachs

Author(s):  
Gregory V. Vereshchagin ◽  
Alexey G. Aksenov

Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan

This chapter covers the equations governing the evolution of particle distribution and relates the macroscopic thermodynamical quantities to the distribution function. The motion of N particles is governed by 6N equations of motion of first order in time, written in either Hamiltonian form or in terms of Poisson brackets. Thus, as this chapter shows, as the number of particles grows it becomes necessary to resort to a statistical description. The chapter first introduces the Liouville equation, which states the conservation of the probability density, before turning to the Boltzmann–Vlasov equation. Finally, it discusses the Jeans equations, which are the equations obtained by taking various averages over velocities.


2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Elizabeth A. Tolman ◽  
Peter J. Catto

Upcoming tokamak experiments fuelled with deuterium and tritium are expected to have large alpha particle populations. Such experiments motivate new attention to the theory of alpha particle confinement and transport. A key topic is the interaction of alpha particles with perturbations to the tokamak fields, including those from ripple and magnetohydrodynamic modes like Alfvén eigenmodes. These perturbations can transport alphas, leading to changed localization of alpha heating, loss of alpha power and damage to device walls. Alpha interaction with these perturbations is often studied with single-particle theory. In contrast, we derive a drift kinetic theory to calculate the alpha heat flux resulting from arbitrary perturbation frequency and periodicity (provided these can be studied drift kinetically). Novel features of the theory include the retention of a large effective collision frequency resulting from the resonant alpha collisional boundary layer, correlated interactions over many poloidal transits and finite orbit effects. Heat fluxes are considered for the example cases of ripple and the toroidal Alfvén eigenmode (TAE). The ripple heat flux is small. The TAE heat flux is significant and scales with the square of the perturbation amplitude, allowing the derivation of constraints on mode amplitude for avoidance of significant alpha depletion. A simple saturation condition suggests that TAEs in one upcoming experiment will not cause significant alpha transport via the mechanisms in this theory. However, saturation above the level suggested by the simple condition, but within numerical and experimental experience, which could be accompanied by the onset of stochasticity, could cause significant transport.


Sign in / Sign up

Export Citation Format

Share Document