Unstable spectrum of a relativistic electron beam interacting with a quantum collisional plasma: application to the fast ignition scenario

Abstract

Abstract. Quantum and collisional effects on the unstable spectrum of a relativistic electron beam-plasma system are investigated through a two-fluids model. Application is made to the near target center interaction of the relativistic electron beam in the Fast Ignition Scenario. Partial degeneracy effects are found negligible while the most influential factors are the beam temperature and the electron-ion collision frequency of the plasma. The introduction of the latter triggers some oblique unstable modes of much larger wave length than the collisionless ones. Transition from the collisionless regime to the resistive one is thus documented and found discontinuous.

Observation of resistive Weibel instability in intense laser plasma

“…This offers a route to control and investigate these instabilities, which may otherwise prove detrimental for fast ignition experiments. Also, the magnetic fields of about 10 4 T are observed in the simulation, which may have implications in the astrophysical scenario (Cassam-Chenai et al, 2008;Suzuki-Vidal, 2015), that is, when a supernova collapses to form a neutron star a similar counter streaming charged particles may give rise to instability leading to generation of strong magnetic field. Charged particles streaming in such high magnetic fields may also contribute to gamma ray bursts.…”

“…The efficiency of energy transport becomes very poor and intense fast electrons cannot transport beyond the filament length (Bell and Kingham, 2003). Instabilities have been modeled by connecting collisional and collisionless plasmas (Bret, 2010) and also by considering quantum effects in the pre-compressed target (Bret et al, 2009) in order to understand the effects on the energy transfer from beam to pellet in the fast ignition scenario.…”

Collisional effects on the relativistic current-filamentation instability in dense plasmas

“…Since the fusion target is dense and cold, collisions between the background plasma particles will obviously alter the CFI. The transition from collisionless filamentation, generating small scale filaments, to resistive filamentation with large scale filaments has been discussed (Bret et al, 2009;Bret, 2010).…”

Quantum effects in beam-plasma instabilities

“…Degenerate plasmas are quantum, but some non-degenerate plasmas may be quantum as well.The study of quantum plasmas can eventually be traced back to the first days of solid state physics, as certain of its aspects can be approached forgetting about the lattice nature of the background ions [2]. The next motivations for quantum plasma studies came from the physics of dense astrophysical objects [3] and from Inertial Confinement Fusion (ICF).Regarding the later, an Deuterium-tritium target in pre-ignition conditions should meet T ∼ 10 7 K with N ∼ 10 25 , placing it at the border of the degeneracy frontier.The investigation of streaming instabilities in quantum plasma arises naturally when considering the multi-stream plasma model [4,5] and has been directly needed recently to deal with the Fast Ignition Scenario for ICF [6,7]. Besides these motivations, streaming instabilities are part of any plasma physics textbook, and it is natural to revisit them from the quantum point of view.Quantum plasmas have been so far mostly investigated in the non-relativistic weakly cou-…”