The filamentation instability was observed in the interaction of two counter-streaming laser ablated plasma flows, which were supersonic, collisionless, and also closely relevant to astrophysical conditions. The plasm...The filamentation instability was observed in the interaction of two counter-streaming laser ablated plasma flows, which were supersonic, collisionless, and also closely relevant to astrophysical conditions. The plasma flows were created by irradiating a pair of oppositely standing plastic (CH) foils with Ins-pulsed laser beams of total energy of 1.7 kJ in two laser spots. With characteristics diagnosed in experiments, the calculated features of Weibel-type filaments are in good agreement with measurements.展开更多
The collisional current-filamentation instability (CFI) is studied for a nonrelativistic electron beam penetrating an infinite uniform plasma. It is analytically shown that the CFI is driven by the drift-anisotropy ra...The collisional current-filamentation instability (CFI) is studied for a nonrelativistic electron beam penetrating an infinite uniform plasma. It is analytically shown that the CFI is driven by the drift-anisotropy rather than the classical anisotropy of the beam and the background plasma. Therefore, collisional effects can either attenuate or enhance the CFI depending on the drift-anisotropy of the beam-plasma system. Numerical results are given for some typical parameters, which show that collisional effects cannot stabilize but enhance the CFI in a dense plasma. Thus, the CFI may play a dominant role in the fast electron transport and deposition relevant to the fast ignition scenario (FIS).展开更多
Interactions of two counter-streaming plasmas driven by high power laser pulses are studied on Shenguang II laser facility.Filamentary structures were observed in the interaction region after the electrostatic shockwa...Interactions of two counter-streaming plasmas driven by high power laser pulses are studied on Shenguang II laser facility.Filamentary structures were observed in the interaction region after the electrostatic shockwave decay.Theoretical analysis and observations indicate that the filaments are because of collisionless mechanisms,which are caused by the electromagnetic instability,such as the beam-Weibel instability.Collision experiments were also carried out for comparison and no filaments were generated.展开更多
Thanks to a rapid progress of high-power lasers since the birth of laser by T.H.Maiman in 1960,intense lasers have been developed mainly for studying the scientific feasibility of laser fusion.Inertial confinement fus...Thanks to a rapid progress of high-power lasers since the birth of laser by T.H.Maiman in 1960,intense lasers have been developed mainly for studying the scientific feasibility of laser fusion.Inertial confinement fusion with an intense laser has attracted attention as a new future energy source after two oil crises in the 1970s and 1980s.From the beginning,the most challenging physics is known to be the hydrodynamic instability to realize the spherical implosion to achieve more than 1000 times the solid density.Many studies have been performed theoretically and experimentally on the hydrodynamic instability and resultant turbulent mixing of compressible fluids.During such activities in the laboratory,the explosion of supernova SN1987A was observed in the sky on 23 February 1987.The X-ray satellites have revealed that the hydrodynamic instability is a key issue to understand the physics of supernova explosion.After collaboration between laser plasma researchers and astrophysicists,the laboratory astrophysics with intense lasers was proposed and promoted around the end of the 1990s.The original subject was mainly related to hydrodynamic instabilities.However,after two decades of laboratory astrophysics research,we can now find a diversity of research topics.It has been demonstrated theoretically and experimentally that a variety of nonlinear physics of collisionless plasmas can be studied in laser ablation plasmas in the last decade.In the present paper,we shed light on the recent 10 topics studied intensively in laboratory experiments.A brief review is given by citing recent papers.Then,modeling cosmic-ray acceleration with lasers is reviewed in a following session as a special topic to be the future main topic in laboratory astrophysics research.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11074297,11674146,and 11220101002)the National Basic Research Program of China(Grant No.2013CBA01500
文摘The filamentation instability was observed in the interaction of two counter-streaming laser ablated plasma flows, which were supersonic, collisionless, and also closely relevant to astrophysical conditions. The plasma flows were created by irradiating a pair of oppositely standing plastic (CH) foils with Ins-pulsed laser beams of total energy of 1.7 kJ in two laser spots. With characteristics diagnosed in experiments, the calculated features of Weibel-type filaments are in good agreement with measurements.
基金Supported by National Natural Science Foundation of China (10425416, 10674175, 60621063)National High-Tech ICF Com-mitteeNational Basic Research Program of China (2007CB815101, 2007CB815105)
文摘The collisional current-filamentation instability (CFI) is studied for a nonrelativistic electron beam penetrating an infinite uniform plasma. It is analytically shown that the CFI is driven by the drift-anisotropy rather than the classical anisotropy of the beam and the background plasma. Therefore, collisional effects can either attenuate or enhance the CFI depending on the drift-anisotropy of the beam-plasma system. Numerical results are given for some typical parameters, which show that collisional effects cannot stabilize but enhance the CFI in a dense plasma. Thus, the CFI may play a dominant role in the fast electron transport and deposition relevant to the fast ignition scenario (FIS).
基金supported by the National Natural Science Foundation of China(Grant Nos.11135012,10925421,11375262 and 11220101002)the National Basic Research Program of China(Grant No.2013CBA01501)
文摘Interactions of two counter-streaming plasmas driven by high power laser pulses are studied on Shenguang II laser facility.Filamentary structures were observed in the interaction region after the electrostatic shockwave decay.Theoretical analysis and observations indicate that the filaments are because of collisionless mechanisms,which are caused by the electromagnetic instability,such as the beam-Weibel instability.Collision experiments were also carried out for comparison and no filaments were generated.
基金supported by the JSPS KAKENHI under Grant Nos.19K21865,19H00668,and 20KK0064。
文摘Thanks to a rapid progress of high-power lasers since the birth of laser by T.H.Maiman in 1960,intense lasers have been developed mainly for studying the scientific feasibility of laser fusion.Inertial confinement fusion with an intense laser has attracted attention as a new future energy source after two oil crises in the 1970s and 1980s.From the beginning,the most challenging physics is known to be the hydrodynamic instability to realize the spherical implosion to achieve more than 1000 times the solid density.Many studies have been performed theoretically and experimentally on the hydrodynamic instability and resultant turbulent mixing of compressible fluids.During such activities in the laboratory,the explosion of supernova SN1987A was observed in the sky on 23 February 1987.The X-ray satellites have revealed that the hydrodynamic instability is a key issue to understand the physics of supernova explosion.After collaboration between laser plasma researchers and astrophysicists,the laboratory astrophysics with intense lasers was proposed and promoted around the end of the 1990s.The original subject was mainly related to hydrodynamic instabilities.However,after two decades of laboratory astrophysics research,we can now find a diversity of research topics.It has been demonstrated theoretically and experimentally that a variety of nonlinear physics of collisionless plasmas can be studied in laser ablation plasmas in the last decade.In the present paper,we shed light on the recent 10 topics studied intensively in laboratory experiments.A brief review is given by citing recent papers.Then,modeling cosmic-ray acceleration with lasers is reviewed in a following session as a special topic to be the future main topic in laboratory astrophysics research.