Laser Plasma

 Introduction

 Fast Ignition

 I C F

 Experiments

 PIC Modelling

Laser Plasmas

What is Fast Ignition?

by Dr. J. Pasley (email: jpasley@ucsd.edu)

Fast Ignition is a special approach to Inertial Confinement Fusion (ICF) in which the energy to heat the fuel come from a separate laser, rather than from the implosion process. This allows for the fuel to be heated more efficiently. It is quite inefficient to heat fuel by the process of implosion. There are a number of approaches to Fast Ignition that are under current study. The one that we are primarily involved in investigating is that known as ‘Re-entrant cone guided fast ignition’. In this approach a small gold cone is imbedded into the side of the spherical fuel capsule, providing a clear pathway to the central region where the compressed fuel globule is formed.
The ultraintense laser that ignites the fuel is fired into the cone. Where it interacts with the cone tip an enormous number of extremely energetic electrons are generated. These electrons fly out into the fuel, heating it to the temperatures required for fusion.

Re-entrant Cone Guided Fast Ignition is a 3 step process. The implosion is driven by soft x-ray or laser radiation (1). A dense fuel globule is formed at the tip of the cone (2). Finally an ultraintense igniter laser injects energetic electrons into the fuel, heating it to the conditions required for fusion (3).