• Special Issue
  • Laser for Fusion
  • 9 Article (s)
Inertial confinement fusion and prospects for power production
C.B. Edwards, and C.N. Danson
High Power Laser Science and Engineering
  • Publication Date: Jan. 01, 1900
  • Vol.3 Issue, 1 010000e4 (2015)
Temperature dependence of parametric instabilities in the context of the shock-ignition approach to inertial confinement fusion
S. Weber, and C. Riconda
The role of the coronal electron plasma temperature for shock-ignition conditions is analysed with respect to the dominant parametric processes: stimulated Brillouin scattering, stimulated Raman scattering, two-plasmon decay (TPD), Langmuir decay instability (LDI) and cavitation. TPD instability and cavitation are sensitive to the electron temperature. At the same time the reflectivity and high-energy electron production are strongly affected. For low plasma temperatures the LDI plays a dominant role in the TPD saturation. An understanding of laser–plasma interaction in the context of shock ignition is an important issue due to the localization of energy deposition by collective effects and hot electron production. This in turn can have consequences for the compression phase and the resulting gain factor of the implosion phase.
High Power Laser Science and Engineering
  • Publication Date: Jan. 01, 1900
  • Vol.3 Issue, 1 010000e6 (2015)
Irradiation uniformity at the Laser MegaJoule facility in the context of the shock ignition scheme
Mauro Temporal, Benoit Canaud, Warren J. Garbett, Rafael Ramis, and Stefan Weber
The use of the Laser MegaJoule facility within the shock ignition scheme has been considered. In the first part of the study, one-dimensional hydrodynamic calculations were performed for an inertial confinement fusion capsule in the context of the shock ignition scheme providing the energy gain and an estimation of the increase of the peak power due to the reduction of the photon penetration expected during the high-intensity spike pulse. In the second part, we considered a Laser MegaJoule configuration consisting of 176 laser beams that have been grouped providing two different irradiation schemes. In this configuration the maximum available energy and power are 1.3 MJ and 440 TW. Optimization of the laser–capsule parameters that minimize the irradiation non-uniformity during the first few ns of the foot pulse has been performed. The calculations take into account the specific elliptical laser intensity profile provided at the Laser MegaJoule and the expected beam uncertainties. A significant improvement of the illumination uniformity provided by the polar direct drive technique has been demonstrated. Three-dimensional hydrodynamic calculations have been performed in order to analyse the magnitude of the azimuthal component of the irradiation that is neglected in two-dimensional hydrodynamic simulations.
High Power Laser Science and Engineering
  • Publication Date: Jan. 01, 1900
  • Vol.2 Issue, 2 020000e8 (2014)
Beam guiding system geometric arrangement in the target area of high-power laser drivers
Lei Ren, Dongfeng Zhao, and Jianqiang Zhu
With the increasing number of laser beams, the main difficulty in arranging beam guiding systems (BGSs) involves determining the corresponding relationships between the output and input ports to realize the identified light path length of all beams. Given the basic constraints of geometric arrangement, a BGS model is established, and a base-line algorithm is proposed to address the difficulty mentioned above. Boundary conditions of target area and target chamber are discussed to increase the number of laser beams, and a maximum value exists for a specific target area. Finally, the compatibility of a cylindrical hohlraum target chamber with a spherical hohlraum is analyzed, and a moveable final optics assembly is proposed to execute the switch between the two different targets.
High Power Laser Science and Engineering
  • Publication Date: Jan. 01, 1900
  • Vol.3 Issue, 1 01000e12 (2015)
Mechanistic study of continuous polishing
Xiang Jiao, Jianqiang Zhu, Quantang Fan, and Yangshuai Li
To establish the mechanism of surface change in a continuous polishing system, an ideal mathematical model is built based on Winkler’s hypothesis and the Preston equation. The basic features of the model are the change rates in the surface peak–valley (PV) values of the workpiece, conditioning disk and pitch lap, rather than the specific surface shapes. In addition, an equilibrium state exists in the system, indicating that the surface change rates are all zero. Under equilibrium, the surface of the lap could remain flat, and it is insensitive to the surface error of the workpiece. These characteristics lay the theoretical foundations for high-efficiency and high-precision polishing. The methods to obtain an equilibrium state with flat surfaces are then proposed and confirmed experimentally. High-precision surfaces better than are consistently produced experimentally.
High Power Laser Science and Engineering
  • Publication Date: Jan. 01, 1900
  • Vol.3 Issue, 2 02000e16 (2015)
Design of kJ-class HiLASE laser as a driver for inertial fusion energy – CORRIGENDUM
Antonio Lucianetti, Magdalena Sawicka, Ondrej Slezak, Martin Divoky, Jan Pilar, Venkatesan Jambunathan, Stefano Bonora, Roman Antipenkov, and Tomas Mocek
High Power Laser Science and Engineering
  • Publication Date: Jan. 01, 1900
  • Vol.2 Issue, 3 03000e23 (2014)