The irradiation of few-nm-thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse.The targets decompress to near and...The irradiation of few-nm-thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse.The targets decompress to near and lower than critical densities with plasmas extending over few micrometers,i.e.multiple wavelengths.The interaction of the main pulse with such a highly localized but inhomogeneous target leads to the generation of a short channel and further self-focusing of the laser beam.Experiments at the Glass Hybrid OPCPA Scaled Test-bed(GHOST)laser system at University of Texas,Austin using such targets measured non-Maxwellian,peaked electron distribution with large bunch charge and high electron density in the laser propagation direction.These results are reproduced in 2D PIC simulations using the EPOCH code,identifying direct laser acceleration(DLA)[1]as the responsible mechanism.This is the first time that DLA has been observed to produce peaked spectra as opposed to broad,Maxwellian spectra observed in earlier experiments[2].This high-density electrons have potential applications as injector beams for a further wakefield acceleration stage as well as for pump-probe applications.展开更多
1.Introduction Calcium phosphate ceramics,such as hydroxyapatite or tricalciumphosphate as well as bioglass,are successfully used as coatings to improve the fixation of dental implants or load-bearing implants in the ...1.Introduction Calcium phosphate ceramics,such as hydroxyapatite or tricalciumphosphate as well as bioglass,are successfully used as coatings to improve the fixation of dental implants or load-bearing implants in the human bone[1].The demand for surgical procedures such as hip and knee arthroplasties,primary as well as revision procedures,is projected to increase for the foreseeable future[2].The possibility of an infection is amajor risk for all implants[3].The treatment of these periprosthetic joint infections is difficult and often requires the replacement of the implant[4],which is a significant burden for the patient and comes at an increased economic cost[5].展开更多
基金supported by NNSA cooperative agreement DE-NA0002008the Defense Advanced Research Projects Agency's PULSE program(12-63-PULSE-FP014)the Air Force Office of Scientific Research(FA9550-14-1-0045).
文摘The irradiation of few-nm-thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse.The targets decompress to near and lower than critical densities with plasmas extending over few micrometers,i.e.multiple wavelengths.The interaction of the main pulse with such a highly localized but inhomogeneous target leads to the generation of a short channel and further self-focusing of the laser beam.Experiments at the Glass Hybrid OPCPA Scaled Test-bed(GHOST)laser system at University of Texas,Austin using such targets measured non-Maxwellian,peaked electron distribution with large bunch charge and high electron density in the laser propagation direction.These results are reproduced in 2D PIC simulations using the EPOCH code,identifying direct laser acceleration(DLA)[1]as the responsible mechanism.This is the first time that DLA has been observed to produce peaked spectra as opposed to broad,Maxwellian spectra observed in earlier experiments[2].This high-density electrons have potential applications as injector beams for a further wakefield acceleration stage as well as for pump-probe applications.
基金The authors would like to thank the Deutsche Forschungsgemeinschaft DFG for the funding of this work under grant GA 589/11-1 and BE 1964/8-1.
文摘1.Introduction Calcium phosphate ceramics,such as hydroxyapatite or tricalciumphosphate as well as bioglass,are successfully used as coatings to improve the fixation of dental implants or load-bearing implants in the human bone[1].The demand for surgical procedures such as hip and knee arthroplasties,primary as well as revision procedures,is projected to increase for the foreseeable future[2].The possibility of an infection is amajor risk for all implants[3].The treatment of these periprosthetic joint infections is difficult and often requires the replacement of the implant[4],which is a significant burden for the patient and comes at an increased economic cost[5].
