Plasma scale-length effects on electron energy spectra in high-irradiance laser plasmas

WOS:000373585800006 PubMed:27176413 An analysis of an electron spectrometer used to characterize fast electrons generated by ultraintense (10(20) W cm(-2)) laser interaction with a preformed plasma of scale length measured by shadowgraphy is presented. The effects of fringing magnetic fields on the electron spectral measurements and the accuracy of density scale-length measurements are evaluated. 2D EPOCH PIC code simulations are found to be in agreement with measurements of the electron energy spectra showing that laser filamentation in plasma preformed by a prepulse is important with longer plasma scale lengths (> 8 mu m). RFBR Research Project [15-32-21121]; RAS Presidium Program for Basic Research [13]; UK EPSRCEngineering & Physical Sciences Research Council (EPSRC) [EP/G054950/1, EP/G056803/1, EP/G055165/1, EP/M022463/1]; Engineering and Physical Sciences Research CouncilEngineering & Physical Sciences Research Council (EPSRC) [EP/M022463/1, EP/G056803/1] The authors gratefully acknowledge the assistance of laser operations, target preparation, and engineering staff at the Central Laser Facility of RAL. Part of the research was supported by RFBR Research Project No. 15-32-21121 and RAS Presidium Program for Basic Research No. 13. This work was in part funded by the UK EPSRC Grants No. EP/G054950/1, No. EP/G056803/1, No. EP/G055165/1, and No. EP/M022463/1.