ABSTRACT
Experimental plasma physics has always been a multi-disciplinary field, especially at high electron densities ne ( 1012cm−3). At these densities, the apparatus needed to produce, manipulate, and study plasma is usually large and complex. Laboratories performing work in laser-plasma accelerators, such as laser-driven “laser wakefield accelerators” (LWFA) or electron/positron-driven “plasma wakefield accelerators” (PWFA) are no exception, becoming increasingly complex as this field moves further away from “proof-of-principle” experiments. From the recent breakthroughs in the last few years, such as the observation of “monoenergitic” GeV electrons from a LWFA experiment (Leemans et al 2006) and the energy-doubling of electrons initially at ∼ 40GeV in a PWFA experiment (Blumenfeld et al 2006), one can draw the happy conclusion that modern laboratories can indeed create the plasma accelerator structures that will have high impact on other areas of science and technology; those requiring light sources or high-energy particles. On the other hand, one could observe that these recent successes were the natural outcome of improvements to the laboratory infrastructure; for example, bigger lasers and better electron beams. As a practical experimentalist, this author leans towards the latter view and that we are very much still in the research stage with “development” still well down the road. Indeed, the growth in the plasma accelerator field has and continues to be built upon the breakthroughs of the past decades-we remain in this evolutionary period and many of the challenges ahead have been challenges from the start.
