학술논문
Controlling fast electron beam divergence using two laser pulses
Document Type
Working Paper
Author
Scott, R. H. H.; Beaucourt, C.; Schlenvoigt, H. -P.; Markey, K.; Lancaster, K. L.; Ridgers, C. P.; Brenner, C. M.; Pasley, J.; Gray, R. J.; Musgrave, I. O.; Robinson, A. P. L; Li, K.; Notley, M. M.; Davies, J. R.; Baton, S. D.; Santos, J. J.; Feugeas, J. -L.; Nicolaï, Ph.; Malka, G.; Tikhonchuk, V. T.; McKenna, P.; Neely, D.; Rose, S. J.; Norreys, P. A.
Source
Subject
Language
Abstract
This paper describes the first experimental demonstration of the guiding of a relativistic electron beam in a solid target using two co-linear, relativistically intense, picosecond laser pulses. The first pulse creates a magnetic field which guides the higher current fast electron beam generated by the second pulse. The effects of intensity ratio, delay, total energy and intrinsic pre-pulse are examined. Thermal and K{\alpha} imaging showed reduced emission size, increased peak emission and increased total emission at delays of 4 - 6 ps, an intensity ratio of 10 : 1 (second:first) and a total energy of 186 J. In comparison to a single, high contrast shot, the inferred fast electron divergence is reduced by 2.7 times, while the fast electron current density is increased by a factor of 1.8. The enhancements are reproduced with modelling and are shown to be due to the self-generation of magnetic fields. Such a scheme could be of considerable benefit to fast ignition inertial fusion.