J. F. Latkowski, S. Reyes, S. A. Payne, W. R. Meier, and J. A. Speth
Lawrence Livermore National Laboratory
The target chamber and final optics in inertial confinement fusion (ICF) experiments and laser-driven inertial fusion energy (IFE) power plants will be subjected to repetitive, intense fluxes of x-rays, ions, and neutrons. While it is possible to design components to avert single-shot ablation there is very little data regarding the effects of multiple shots. Laser damage experiments on metal mirrors indicate that multiple shots result in a significant reduction in the threshold above which damage is observed [1]. If a similar trend is present for x-rays, then damage to the chamber and optics might occur even when models indicate that single-shot damage is avoided.
To provide data for rep-rated x-ray damage, the High Average Power Laser (HAPL) Program is procuring a Z-pinch based x-ray source, provided by PLEX LLC [2]. The PLEX source is capable of generating IFE relevant x-ray fluences at repetition rates of up to 10 Hz with very low quantities of debris. Operation for 10 million pulses has been demonstrated. As part of the HAPL Program, the facility will be used to test the baseline materials÷graphite and tungsten for the chamber first wall and aluminum and fused silica for the final optic. Opportunities for contributions to heavy-ion fusion (in particular to the study of wetted-wall concepts) appear to be promising. Although ICF facilities are not forced to contend with the high rep-rate issues present in IFE, many components will be exposed to numerous shots. The PLEX source will offer the ICF community the opportunity to generate statisticallyÊ significant data sets in a relatively short period of time. The present work will detail the experimental plan for use of this source for both IFE and ICF applications.
[1]Ê M. R. Zaghloul, M. S. Tillack, and T. K. Mau, ãSensitivity of Metal Mirrors to Laser-Induced Damage Under Long-Term Exposure at Shallow Angle of Incidence,ä Presented at the Nineteenth IEEE/NPSS Symposium on Fusion Energy, Atlantic City, NJ (Oct. 2001).
[1]Ê M. R. Zaghloul, M. S. Tillack, and T. K. Mau, ãSensitivity of Metal Mirrors to Laser-Induced Damage Under Long-Term Exposure at Shallow Angle of Incidence,ä Presented at the Nineteenth IEEE/NPSS Symposium on Fusion Energy, Atlantic City, NJ (Oct. 2001).
