In order to implement a Scenario of π− catalysis of Deuterium–Tritium (DT) thermonuclear reactions in a dense and hot precompressed target plasma envisioned in the Intertial Confinement Fusion (ICF) fast ignition approach, we pay detailed attention to the stopping of negative pions arising from electro-disintregration of target D and T nuclei by ultra-relativistic e-beams. Emphasis is put on a mostly non-relativistic pion velocity regime (E ≤ 10 MeV).

Ultra-cold plasmas obtained by ionization of atomic Rydberg states are qualified as classical and strongly coupled electron fluids. They are shown to share several common trends with ultra-cold electron flows used for ion-beam cooling. They exhibit specific stopping behaviour to charged particle beams, which may be used for diagnostic purposes. Ultra-cold plasmas are easily strongly magnetized. Then, one expects a strongly anisotropic behaviour of low ion velocity slowing down when the target electron cyclotron radius becomes smaller than the corresponding Debye length.

Correlated stopping of N ion debris flowing at same velocity in a lithium target is worked out from the Basbas-Ritchie model of 2-cluster stopping in degenerate electron jellium. A very large energy loss enhancement is demonstrated. It is strongly modulated by the ions' topological arrangement. Relevance to inertial fusion driven by intense cluster ion beam is stressed.

The stopping at low (V < Vth) and high (V ≤ Vth) velocity, of N strongly correlated ion debris is investigated for the case of a dense and classical electron target. The considered topologies of cluster projectile charges are taken cubic like, and circular, respectively. A specific emphasis is given to the N-dependence, and also to the topological features of the corresponding enhanced correlated stopping.

We reconsider correlated ion stopping in plasmas with the aim to emphasize the basic features and their underlying physics. For a better understanding of the effects connected with correlated ion stopping, it is useful to distinguish two types of correlated ion stopping, characterized by a small or large ratio of the correlation length of the ions to the screening length in the plasma. These two types of correlated ion stopping are of rather different character. We describe and explain these differences and give some generic examples of ion structures and ion clusters to demonstrate the basic features of both types of correlated stopping. This shows that only the short-range correlations always yield an enhanced stopping, whereas the long-range correlations, in general, reduce the stopping compared to single, individual ions. We mainly consider classical plasmas; the basic features, however, remain unchanged for a jellium target as well as for a plasma at any degeneracy.

We evaluate the correlated stopping power of a swift chain of N charges aligned with its (non-relativistic) velocity. We find that the distance required between two charges for the chain to act as a separated set of isolated charges is much larger than the dynamical screening length because the wake effect is very important when the chain elements are situated close to each other.

This article appeared in Volume 24, Number 3, Pages 421–425.

A thorough analysis of the electromagnetic instabilities encountered in the beam plasma interaction physics shows that the most unstable modes are not the ones which are usually studies. We characterize these most unstable modes and determine the patterns they create.

Magnetic confinement fusion (MCF) and inertial confinement fusion (ICF) are critically contrasted in the context of far-distant travels throughout solar system. Both are shown to potentially display superior capabilities for vessel maneuvering at high speed, which are unmatched by standard cryogenic propulsion (SCP). Costs constraints seem less demanding than for ground-based power plants. Main issue is the highly problematic takeoff from earth, in view of safety hazards concomitant to radioactive spills in case of emergency. So, it is recommended to assemble the given powered vessel at high earth altitude ∼ 700 km, above upper atmosphere. Fusion propulsion is also compared to fission powered one, which secures a factor of two improvement over SCP. As far a specific impulse (s) is considered, one expects 500–3000 from fission and as much as 104–105 from fusion through deuterium–tritium (D-T). Next, we turn attention to the most performing fusion reaction, i.e., proton–antiproton annihilation with specific impulse ∼ 103–106 and thrust–to–weight ratio ∼ 10−3–1. Production and costs are timely reviewed. The latter could drop by four orders of magnitude, which is possible with successful MCF or ICF. Appropriate vessel designs will be presented for fusion as well as for antimatter propulsion. In particular, ion compressed antimatter nuclear II (ICAN-II) project to Mars in 30 days with fusion catalyzed by 140 ng of antiprotons will be detailed (specific impulse ∼ 13500 s).

We have focused our attention on the stopping mechanisms involved in the recently proposed ion beam-target US program. This mechanism emphasizes out production of warm dense matter through pulsed ion beams, linearly accelerated, and interacting with thin foils in Bragg peak conditions. We reviewed the relevant energy loss mechanisms involved at moderate and low velocity ion projectile. Small velocities close to zero are given some attention.

In the fast ignition scenario for inertial fusion, a relativistic electron beam is supposed to travel from the side of the fusion pellet to its core. One one hand, a relativistic electron beam passing through a plasma is a highly unstable system. On the other hand, the pellet core is denser than its side by four orders of magnitude so that the beam makes its way through a important density gradient. We here investigate the effect of this gradient on the instabilities. It is found that they should develop so early that gradient effects are negligible in the linear phase.

We will consider relativistic electron beam interacting with plasma and study the electromagnetic instabilities obtained for arbitrarily oriented wave vectors ranging from two-stream to filamentation instabilities. For these unstable modes, we will study every temperature effects, namely beam and plasma normal, and parallel temperatures. Temperatures are supposed to be non-relativistic and modeled through water bag distributions. It is found that only normal beam temperature and parallel plasma temperature have a significative influence over the growth rates for wave vector making an angle with the beam larger than a critical angle θc which is determined exactly. The largest growth rate being reached for a wave vector making an angle with the beam smaller than θc, it is not damped by any kind of temperatures. We finally explore collisions effects and show they can reduce the largest growth rate.

We investigate intermediate unstable modes between two stream and filamentation instabilities. We detail the problem of the angle between the wave vector and its electric field and use an electromagnetic formalism allowing for any value for this angle. We display analytical results for 3 different models: cold beam-cold plasma, cold beam-hot plasma and cold relativistic beam-hot plasma. We demonstrate that plasma temperature prompts a critical angle for which waves are unstable at any k and show that for a relativistic beam, the most unstable waves are obtained for wave vectors which are neither normal nor perpendicular to the beam.

Volume 23, Number 1, Pages 5–8, 2005

Below is the complete Reference citation for Bret et al. (2005).

Bret, A., Firp, M.-C. & Deutsch, C. (2005). Bridging the gap between two stream and filamentation instabilities. Laser Part. Beams 23, 373–381.

We address the issues of collective stopping for intense relativistic electron beams (REB) used to selectively ignite precompressed deuterium + tritium (DT) fuels. We investigate the subtle interplay of electron collisions in target as well as in beam plasmas with quasi-linear electromagnetic growth rates. Intrabeam scattering is found effective in taming those instabilities, in particular for high transverse temperatures.

Two distinct issues of recent concern for ion–plasma interactions are investigated. First, the subtle connection between quantum and classical ion stopping is clarified by varying the space dimension. Then we evaluate the range of thermonuclear αS′ in dense plasmas simultaneously magnetized and compressed.