StarDriver: Recent results on beam smoothing and LPI mitigation

Abstract

StarDriver was recently proposed as a highly flexible laser driver for inertial confinement fusion and high energy density physics. It envisions a laser drive consisting of very many beams at an aperture and energy where the optical technology is well-developed, used in concert to create a large scale laser driver system. In this paper we describe a StarDriver-class laser with 5120 physical beamlets disposed about the target chamber in 80 evenly spaced ports, each port containing 64 beamlets, each beamlet having about ∼1.5THz of 2D SSD bandwidth and suitable phase plates, an aperture of ∼65mm, an energy of 80J, and frequency-converted to ∼351nm.many beamlets at an aperture where optical technology is well-developed, and each beamlet has energy ∼100J in a several times diffraction limited beam. The ensemble of beamlets has frequency bandwidth 2%-10%, thereby providing significant control of both hydrodynamic and laser-plasma instabilities The drive at the target is ∼400kJ, has a well-behaved low L-mode spectrum, and smooths very rapidly, reaching an asymptotic smoothness of <1% in less than Ins.