Beam-plasma instabilities can produce highly non-linear effects that can influence the particle dynamics of a system. Within fast-ignition inertial confinement fusion, the two-stream instability may be of particular importance. In this form of fusion, a deuterium-tritium fuel pellet is compressed using uniform laser irradiation. A secondary laser pulse is then utilised to accelerate a highly relativistic electron beam into the core of the pellet to provide the heating necessary to initiate fusion. Results from fast-ignition fusion experiments have indicated that more of the beam energy is being transferred to the ion population than would be expected from purely electron-ion collisions. It has been proposed that this anomalous heating mechanism can be explained by the two-stream instability. As the beam propagates through the compressed pellet, the two-stream instability occurs and can excite Langmuir turbulence that can resonantly decay into ion-acoustic waves. These waves are then damped by ion-ion collisions resulting in a collective heating of the ion population. To investigate this behaviour, a scaled low temperature, low density laboratory experiment is currently underway. Two dimensional particle-in-cell (PiC) simulations have been undertaken of this scaled experiment, the results of which will be benchmarked against those of the experiment. Preliminary results from the laboratory experiment will be presented along with the results from PiC simulations.
|Title of host publication||40th EPS Conference on Plasma Physics, EPS |
|Number of pages||4|
|Publication status||Published - 2013|