Colin Danson

Abstract:

The possibility of using high-intensity laser-produced plasmas as a source of energetic ions for heavy ion accelerators is addressed. Experiments have shown that neon ions greater than 6 MeV can be produced from gas jet plasmas, and well-collimated proton beams greater than 20 MeV have been produced from high-intensity laser solid interactions. The proton beams from the back of thin targets appear to be more collimated and reproducible than are high-energy ions generated in the ablated plasma at the front of the target and may be more suitable for ion injection applications. Lead ions have been produced at energies up to 430 MeV.

Abstract:

The Rutherford Appleton Laboratory has been at the forefront of investigations into the physics associated with the fast ignition concept for inertial confinement fusion. This scheme involves complex laser-plasma processes, the theoretical understanding of which relies heavily on particle-in-cell calculations. In this paper, three experiments displaying quantitative agreement with detailed multi-dimensional PIC calculations are reviewed: hole-boring velocity measurements; relativistic self-focusing; and harmonic generation from plasma surfaces. Qualitative agreement of hot electron temperature measurements with PIC simulations are also discussed. The authors believe these results are very encouraging for the fast ignition concept. (C) 1999 Published by Elsevier Science S.A. All rights reserved.

Abstract:

The Strickland-Mourou technique of Chirped Pulse Amplification (CPA) is now in common use on many laser systems and has resulted in massive increases in focused intensities. Implemented on the Vulcan laser system, the technique has generated multi-Joule subpicosecond pulses whilst maintaining beam quality to produce focused intensities of 5×1019 W cm-2.

Abstract:

Peak intensities of 10¹⁹ W cm² have been reliably obtained from a high power Nd:glass laser using chirped pulse amplification. An Additive Pulse Modelocked oscillator incorporating diode pumped Nd:LMA was used to generate the sub-picosecond pulse. The focal spot intensity distribution has been characterized in detail showing a three times diffraction limited beam. © 1998 Taylor & Francis Group, LLC.