The paper deals with a generic problem of collisionless plasma expansion into vacuum in the regimes where the expanding plasma consists of hot electrons and cold ions. The expansion is caused by electron pressure and serves as an energy transfer mechanism from electrons to ions. This process is often described under the assumption of Maxwellian electrons, which easily fails in the absence of co...

Using a weighted Hs-contraction mapping argument based on the macro-micro decomposition of Liu and Yu, we give an elementary proof of existence, with sharp rates of decay and distance from the Chapman–Enskog approximation, of small-amplitude shock profiles of the Boltzmann equation with hard-sphere potential, recovering and slightly sharpening results obtained by Caflisch and Nicolaenko using d...

Recent observations from the EISCAT neutral thermal speed. However, for larger incoherent scatter radar have revealed bursts of drifts the distribution function is predicted to poleward ion flow in the dayside auroral ionosbe highly non-Maxwellian and takes the form of a phere which are consistent with the ionospheric torus in velocity space (symmetric about the signature of flux transfer event...

The mechanisms by which RNA polymerase moves along DNA during elongation have been difficult to determine experimentally. In this issue of Cell, Bar-Nahum et al. (2005) show that back and forth sliding of RNA polymerase on DNA may be coupled to bending of an alpha helix, which can alternately occlude and expose the NTP binding site. Transcription factors can regulate elongation by modulating th...

By direct interpolation of a family of smooth energy estimates for solutions near Maxwellian equilibrium and in a periodic box to several Boltzmann type equations in [7–9, 11], we show convergence to Maxwellian with any polynomial rate in time. Our results not only resolve the important open problem for both the Vlasov-Maxwell-Boltzmann system and the relativistic Landau-Maxwell system for char...

For plasma velocity space instabilities driven by particle distributions significantly deviated from a Maxwellian, weak collisions can damp the an amount that is beyond collisional rate itself. This attributed to dual role of tend relax distribution toward Maxwellian and suppress linearly perturbed function. The former effect dominate in cases where unstable non-Maxwellian collisionless transpo...

The ion side of a closed, fluid and drift-kinetic theoretical model to describe slow and macroscopic plasma processes in a fusion-relevant, low collisionality regime is presented. It follows the ordering assumptions and the methodology adopted in the companion electron theory1. To reach the frequency scale where collisions begin to play a role, the drift-kinetic equation for the ion distributio...

We consider the flow of a gas in a channel whose walls are kept at fixed (different) temperatures. There is a constant external force parallel to the boundaries which may themselves also be moving. The system is described by the stationary Boltzmann equation to which are added Maxwellian boundary conditions with unit accommodation coefficient. We prove that when the temperature gap, the relativ...

We describe a technique for producing a Maxwell–Boltzmann electron energy distribution using an electron beam ion trap ~EBIT!. The technique was implemented on the Lawrence Livermore EBIT to simulate Maxwellian plasmas. We discuss technical and experimental issues related to these simulations. To verify the fidelity of the quasi-Maxwellian, we have measured line emission due to dielectronic rec...

New characteristics of O‡ ion velocity distribution functions in a background of atomic oxygen neutrals subjected to intense external electromagnetic forces are presented. The one dimensional (1-D) distribution function along the magnetic field displays a core-halo shape which can be accurately fitted by a two Maxwellian model. The Maxwellian shape of the 1-D distribution function around a pola...