Novel approach to the Schwinger limit using micro bubble implosion

We propose a novel principle to approach the Schwinger limit using micro-bubble implosion (MBI) [1, 2]. Being supported by the three-dimensional particle simulations, we have developed a semi-analytical 1D model to estimate the attainable electric field with MBI to derive the limiting curve and the relevant scaling in terms of the applied laser intensity, the spatial degree of ionization, and the bubble radius. Introducing high-Z materials as the target composition or a surface coating should realize higher attainable electric fields by MBI. It is shown that pair creation becomes active at around the maximum compression of MBI, when the ultrahigh-energy-density nano-sphere is formed at the center. [1] M. Murakami et al., Sci. Rep. 8, 7537 (2018). [2] M. Murakami et al., Plasmas 26, 043112 (2019).