Microjet formation and hard x-ray production from a liquid metal target irradiated by intense femtosecond laser pulses

Abstract

International audienceBy using a liquid metal as a target one may significantly enhance the yield of hard x-rays with a sequence of two intense femtosecond laser pulses. The influence of the time delay between the two pulses is studied experimentally and interpreted with numerical simulations. It was suggested that the first arbitrary weak pulse produces microjets from the target surface, while the second intense pulse provides an efficient electron heating and acceleration along the jet surface. These energetic electrons are the source of x-ray emission while striking the target surface. The microjet formation is explained based on the results given by both optical diagnostics and hydrodynamic modeling by a collision of shocks originated from two distinct zones of laser energy deposition

Simulating the Feasibility of Using Liquid Micro-Jets for Determining Electron–Liquid Scattering Cross-Sections

“…Until now, applications of the aforementioned LµJ designs include an array of photoelectron spectroscopy experiments, to measure properties such as binding energies and hydrogen bonding [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Other LµJ experiments include mass spectrometry [ 56 ], enhanced X-ray production [ 57 , 58 , 59 , 60 ], X-ray emission/absorption, to probe electronic structure and molecule orientation [ 61 , 62 , 63 ], to study the molecular dynamics of evaporation [ 64 ], electrokinetic power generation [ 65 , 66 ], and drug delivery alternatives [ 67 ]. For further general reading, one is directed to the summary papers cited here [ 23 , 68 , 69 ].…”