Two teams take big steps forward in plasma acceleration

摘要

The high electric-field gradients that can be set up in plasma have offered the promise of compact particle accelerators since the late 1970s. The basic idea is to use the space-charge separation that arises in the wake of either an intense laser pulse or a pulse of ultra-relativistic charged particles (CERN Courier June 2007 p28). Towards the end of 2014, groups working on both approaches reached important milestones. One team, working at the Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC, demonstrated plasma-wakefield acceleration with both a high gradient and a high energy-transfer efficiency - a crucial combination not previously achieved. At Lawrence Berkeley National Laboratory, a team working at the Berkeley Lab Laser Accelerator (BELLA) facility boosted electrons to the highest energies ever recorded for the laser-wakefield technique.