Giant electromagnetic pulses(EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot...Giant electromagnetic pulses(EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers(e.g. the Extreme Light Infrastructure).We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3 D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP,providing an opportunity for comparison with existing charge separation models.展开更多
This article describes the fabrication of a suite of laser targets by the Target Fabrication group in the Central Laser Facility(CLF), STFC Rutherford Appleton Laboratory for the first academic-access experiment on th...This article describes the fabrication of a suite of laser targets by the Target Fabrication group in the Central Laser Facility(CLF), STFC Rutherford Appleton Laboratory for the first academic-access experiment on the Orion laser facility(Hopps et al., Appl. Opt. 52, 3597–3601(2013)) at Atomic Weapons Establishment(AWE). This experiment, part of the POLAR project(Falize et al., Astrophys. Space Sci. 336, 81–85(2011); Busschaert et al., New J. Phys. 15, 035020(2013)),studied conditions relevant to the radiation-hydrodynamic processes occurring in a remarkable class of astrophysical star systems known as magnetic cataclysmic variables. A large number of complex fabrication technologies and research and development activities were required to field a total of 80 high-specification targets. Target design and fabrication procedures are described and initial alignment and characterization data are discussed.展开更多
基金funding from EPSRC grants EP/L01663X/1 and EP/L000644/1the Newton UK grant+1 种基金the National Natural Science Foundation of China NSFC/11520101003the LLNL Academic Partnership in ICF
文摘Giant electromagnetic pulses(EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers(e.g. the Extreme Light Infrastructure).We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3 D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP,providing an opportunity for comparison with existing charge separation models.
文摘This article describes the fabrication of a suite of laser targets by the Target Fabrication group in the Central Laser Facility(CLF), STFC Rutherford Appleton Laboratory for the first academic-access experiment on the Orion laser facility(Hopps et al., Appl. Opt. 52, 3597–3601(2013)) at Atomic Weapons Establishment(AWE). This experiment, part of the POLAR project(Falize et al., Astrophys. Space Sci. 336, 81–85(2011); Busschaert et al., New J. Phys. 15, 035020(2013)),studied conditions relevant to the radiation-hydrodynamic processes occurring in a remarkable class of astrophysical star systems known as magnetic cataclysmic variables. A large number of complex fabrication technologies and research and development activities were required to field a total of 80 high-specification targets. Target design and fabrication procedures are described and initial alignment and characterization data are discussed.
