Abstract
The Facility for Advanced Accelerator and Experimental Tests (FACET) at SLAC installed a 10-TW Ti : sapphire laser system for pre-ionized plasma wakefield acceleration experiments. High energy (500 mJ), short (50 fs) pulses of 800 nm laser light at 1 Hz are used at the FACET experimental area to produce a plasma column. The laser pulses are stretched to 250 fs before injection into a vapor cell, where the laser is focused by an axicon lens to form a plasma column that can be sustained over the desired radius and length. A 20 GeV electron bunch interacts with this preformed plasma to generate a non-linear wakefield, thus accelerating a trailing witness bunch with gradients on the order of several GV m−1. The experimental setup and the methods for producing the pre-ionized plasma for plasma wakefield acceleration experiments performed at FACET are described.
Highlights
The Facility for Advanced Accelerator and Experimental Tests (FACET) at the SLAC National Accelerator Laboratory has operated as a National User Facility since 2011
In E-200 plasma wakefield accelerators (PWFA) experiments, a plasma is formed in a heat-pipe oven [2] filled with an alkali metal vapor (Li, Rb or Cs)
This paper describes plasma formation with the 10 TW FACET laser system and the setup for the first experiments, in which laser pulses were compressed to 250 fs, injected into a vapor cell, and focused by an axicon lens to form the plasma
Summary
The Facility for Advanced Accelerator and Experimental Tests (FACET) at the SLAC National Accelerator Laboratory has operated as a National User Facility since 2011. For generation PWFA experiments, long, uniform, high-density (>1016 e− cm−3) plasmas are required to produce a large energy gain in a single meter-scale module, on the order of tens of GeV. With the two-bunch beam parameters at FACET, the drive beam cannot sufficiently ionize the plasma, and even if it could, head erosion would limit the distance over which acceleration can occur. A laser ionization scheme using axicon focusing has been developed to turn Li vapor into a preformed meter-scale homogenous plasma [5]. This paper describes plasma formation with the 10 TW FACET laser system and the setup for the first experiments, in which laser pulses were compressed to 250 fs, injected into a vapor cell, and focused by an axicon lens to form the plasma. The interaction of the 20 GeV FACET electron beam with this preformed plasma leads to acceleration in the wakefield with gradients on the order of a several GeV m−1
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
