Generation of meter-scale hydrogen plasmas and efficient, pump-depletion-limited wakefield excitation using 10 GeV electron bunches
[1];
[3];
[1];
[5];
[2];
[3];
[7];
more »
- University of California, Los Angeles, CA (United States)
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Ecole Polytechnique, Palaiseau (France)
- University of Oslo (Norway)
- Beijing Normal University, Beijing (China)
- University of Colorado, Boulder, CO (United States)
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Institute (PULSE)
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Ecole Polytechnique, Palaiseau (France)
High repetition rates and efficient energy transfer to the accelerating beam are important for a future linear collider based on the beam-driven plasma wakefield acceleration scheme (PWFA-LC). This paper reports the first results from the Plasma Wakefield Acceleration Collaboration (E300) that are beginning to address both of these issues using the recently commissioned FACET-II facility at SLAC national accelerator laboratory. Here we have generated meter-scale hydrogen plasmas using time-structured 10 GeV electron bunches from FACET-II, which hold the promise of dramatically increasing the repetition rate of PWFA by rapidly replenishing the gas between each shot compared to the hitherto used lithium plasmas that operate at 1–10 Hz. Furthermore, we have excited wakes in such plasmas that are suitable for high gradient particle acceleration with high drive-bunch to wake energy transfer efficiency- a first step in achieving a high overall energy transfer efficiency. We have done this by using time-structured electron drive bunches that typically have one or more ultra-high current (> 30 kA) femtosecond spike(s) superimposed on a longer (~0.4 ps) lower current (< 10 kA) bunch structure. The first spike effectively field-ionizes the gas and produces a meter-scale (30–160 cm) plasma, whereas the subsequent beam charge creates a wake. The length and amplitude of the wake depends on the longitudinal current profile of the bunch and plasma density. We find that the onset of pump depletion, when some of the drive beam electrons are nearly fully depleted of their energy, occurs for hydrogen pressure ≥ 1.5Torr. We also show that some electrons in the rear of the bunch can gain several GeV energies from the wake. These results are reproduced by particle-in-cell simulations using the QPAD code. At a pressure of ~2Torr, simulation results and experimental data show that the beam transfers about 60% of its energy to the wake.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- Grant/Contract Number:
- AC02-76SF00515; SC0010064; AC02-05CH11231; HEP-ERCAP-MP113; SC0020076
- OSTI ID:
- 2322473
- Journal Information:
- Plasma Physics and Controlled Fusion, Vol. 66, Issue 2; ISSN 0741-3335
- Publisher:
- IOP ScienceCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator
Dielectric Wakefield Accelerator to drive the future FEL Light Source.