Outstanding progress has been made in high-power laser technology in the last 10 years with laser powers reaching petawatt (PW) values. At present, there are 15 PW lasers built or being built around the world and plans are afoot for new, even higher power, lasers reaching values of exawatt (EW) or even zetawatt (ZW) powers. Petawatt lasers generate electric fields of 10 12 Vm 1 with a large fraction of the total pulse energy being converted to relativistic electrons with energies reaching in excess of 1GeV. In turn these electrons result in the generation of beams of protons, heavy ions, neutrons and high-energy photons. These laser-driven particle beams have encouraged many to think of carrying out experiments normally associated with conventional nuclear accelerators and reactors. To this end a number of introductory articles have been written under a trial name 'Laser Nuclear Physics' (Ledingham and Norreys 1999 Contemp. Phys. 40 367, Ledingham et al 2002 Europhys. News. 33 120, Ledingham et al 2003 Science 300 1107, Takabe et al 2001 J. Plasma Fusion Res. 77 1094). However, even greater strides have been made in the last 3 or 4 years in laser technology and it is timely to reassess the potential of laser-driven particle and photon beams. It must be acknowledged right from the outset that to date laser- driven particle beams have yet to compete favourably with conventional nuclear accelerator-generated beams in any way and so this is not a paper comparing laser and conventional accelerators. However, occasionally throughout the paper as a reality check, it will be mentioned what conventional nuclear accelerators can do.

https://iopscience.iop.org/article/10.1088/1367-2630/12/4/045005/pdf

Laser-driven particle and photon beams and some applications

P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines

The French Commissariat a l'Energie Atomique (CEA) is 
currently building the Laser MegaJoule (LMJ), a 240-beam laser facility, at 
the CEA Laboratory CESTA near Bordeaux. LMJ will be a cornerstone of CEA's 
“Programme Simulation”, the French Stockpile Stewardship Program. LMJ is 
designed to deliver about 2 MJ of 0.35 μm light to targets for high 
energy density physics experiments, among which fusion experiments. LMJ 
technological choices were validated with the Ligne d'Integration Laser 
(LIL), a scale 1 prototype of one LMJ bundle, built at CEA/CESTA. Plasma 
experiments started at the end of 2004 on LIL, which is already open to the 
scientific community through the Plasma and Lasers Institute. The 
construction of the LMJ building itself started in March of 2003. LMJ will 
be gradually commissioned from early 2011, and after an experimental program 
to progress toward fusion, the first fusion experiments will begin late 
2012.

The megajoule laser program — ignition at hand

Plasma-based accelerators have been proposed for the next generation of compact accelerators because of the huge electric fields they can support However, it has been difficult to use them efficiently for applications because they produce poor quality particle beams with large energy spreads Here, we demonstrate a dramatic enhancement in the quality of electron beams produced in laser-plasma interaction: an ultrashort laser pulse drives a plasma bubble which traps and accelerates plasma electrons to a single energy This produces an extremely collimated and quasi-monoenergetic electron beam with a high charge of 05 nanocoulomb at energy 170 ± 20 MeV

Generation of quasi-monoenergetic electron beams using ultrashort and ultraintense laser pulses

The problem of describing charged particle transport in hot plasma under the conditions in which the ratio of the electron mean free path to the gradient length is not too small is one of the key problems of plasma physics. However, up to now, there was a deficit of the systematic interpretation of the current state of this problem, which, in most studies, is formulated as the problem of nonlocal transport. In this review, we fill this gap by presenting a self-consistent linear theory of nonlocal transport for small plasma perturbations and an arbitrary collisionality from the classical highly collisional hydrodynamic regime to the collisionless regime. We describe a number of nonlinear transport models and demonstrate the application of the nonclassical transport theory to the solution of some problems of plasma physics, first of all for plasmas produced by nanosecond laser pulses with intensities of 1013–1016 W/cm2.

Nonlocal transport in hot plasma. Part II

The forthcoming laser installations related to inertial confinement fusion, Laser Megajoule (LMJ) (France) and National Ignition Facility (NIF) (USA), require multidimensional numerical simulation tools for interpreting current experimental data and to perform predictive modeling for future experiments. Simulations of macroscopic plasma volumes of the order of 1 mm^3 and laser exposure times of the order of hundreds of picoseconds are necessary. We present recent developments in the PARAX code towards this goal. The laser field is treated in a standard paraxial approximation in three dimensions. The plasma response is described by single-fluid, two-temperature, fully nonlinear hydrodynamical equations in the plane transverse to the laser propagation axis. The code also accounts for the dominant nonlocal transport terms in spectral form originating from a linearized solution to the Fokker–Planck equation. The simulations of interest are hohlraum plasmas in the case of indirect drive or the plasma corona for direct drive. Recent experimental results on plasma-induced smoothing of RPP laser beams are used to validate the code.

J. Ovadia

Papers

Modeling of laser-plasma interaction on hydrodynamic scales: Physics development and comparison with experiments