Limitations on Plasma Optics due to Non-Linear Ion Wave Physics

The success of plasma optics in producing a high energy beam with a 1ns duration with stimulated Brillouin scatter (SBS) [1,2,3,4] motivates their development for new applications.   We have described a second stage pulse compressor for such a beam that could use SBS to produce a <~ 0.1 ns output pulse [5] with 10’s to 100’s of kJ of energy if non-linear plasma wave effects remain benign.   Suppression of the secondary instabilities of filamentation and backscatter dictates that the 15 cm plasma in such a compressor be <~ 0.1% crit., [5] where particle trapping in the desired ion waves may limit the optics performance, if it is not mitigated by Coulomb collisions.  We describe existing experimental evidence of such non-linearities and compare it with theoretical metrics of trapping and its modification by collisions, to guide the design of new optics as well as motivate modeling of trapping and near term experiments to validate it.

[1] P. Poole in preparation,

[2] R. K. Kirkwood et al Nat. Phys. 14 , 80 (2018).

[3] R. K. Kirkwood  et al Phys. of Plas. 25 056701 (2018).

[4] A Colaitis et al Physics of Plasmas 25, 033114 (2018),

[5] R. K. Kirkwood et al, APS DPP 2020.