Speaker
Description
The petawatt (PW) facility at Berkeley Lab Laser Accelerator (BELLA Center) has successfully performed several experiments since its installation in 2012 [1], primarily focusing on optimization of single stage, high energy gain laser-plasma accelerators (LPAs) [2,3]. Recently, the facility has undergone two significant upgrades: i) a new second beamline (2BL) delivered into the existing experimental chamber, and ii) a new experimental chamber providing capabilities for experiments in tightly focused geometries [4]. This talk focuses on the installation of the new second beamline. To form this, the PW laser pulse is split before compression, and passed through a new compressor chamber, making it capable of delivering up to 500 TW at 1 Hz, synchronous with the existing beamline (1BL). Currently installed is a f=13.5m off-axis parabola, matching the existing beamline, although focusing optics ranging from f=18.5m to short focal length geometries are possible. We show results from low- and high-power commissioning of 2BL, demonstrating temporal compression to 37 fs, high quality focal mode (measured Strehl ratio ≳ 0.8), and good shot-to-shot timing stability between 1BL and 2BL (RMS jitter of 8 fs). We outline plans for three upcoming dual-beam campaigns made possible by this upgrade: staging of 2 LPAs; PW guiding in optically formed plasma channels; and two-color ionization injection.
[1] Nakamura, Kei, et al., IEEE Journal of Quantum Electronics 53.4 (2017): 1-21. (https://doi.org/10.1109/JQE.2017.2708601)
[2] Leemans, W. P., et al., Physical Review Letters 113.24 (2014): 245002. (https://doi.org/10.1103/PhysRevLett.113.245002)
[3] Gonsalves, A. J., et al., Physical Review Letters 122.8 (2019): 084801. (https://doi.org/10.1103/PhysRevLett.122.084801)
[4] Hakimi, Sahel, et al., Physics of Plasmas 29.8 (2022): 083102. (https://doi.org/10.1063/5.0089331)
Acknowledgments
This work was supported by the U.S. Department of Energy Office of Science, Office of High Energy Physics, under Contract No. DE-AC02–05CH11231.
