The interaction between a molecular cloud and an external agent(e.g.,a supernova remnant,plasma jet,radiation,or another cloud)is a common phenomenon throughout the Universe and can significantly change the star forma...The interaction between a molecular cloud and an external agent(e.g.,a supernova remnant,plasma jet,radiation,or another cloud)is a common phenomenon throughout the Universe and can significantly change the star formation rate within a galaxy.This process leads to fragmentation of the cloud and to its subsequent compression and can,eventually,initiate the gravitational collapse of a stable molecular cloud.It is,however,difficult to study such systems in detail using conventional techniques(numerical simulations and astronomical observations),since complex interactions of flows occur.In this paper,we experimentally investigate the compression of a foam ball by Taylor–Sedov blast waves,as an analog of supernova remnants interacting with a molecular cloud.The formation of a compression wave is observed in the foam ball,indicating the importance of such experiments for understanding how star formation is triggered by external agents.展开更多
The collective interaction between intense ion beams and plasmas is studied by simulations and experiments,where an intense proton beam produced by a short pulse laser is injected into a pre-ionized gas.It is found th...The collective interaction between intense ion beams and plasmas is studied by simulations and experiments,where an intense proton beam produced by a short pulse laser is injected into a pre-ionized gas.It is found that,depending on its current density,collective effects can significantly alter the propagated ion beam and the stopping power.The quantitative agreement that is found between theories and experiments constitutes the first validation of the collective interaction theory.The effects in the interaction between intense ion beams and background gas plasmas are of importance for the design of laser fusion reactors as well as for beam physics.展开更多
基金the support of Investissements d’Avenir of LabEx PALM(Grant No.ANR-10-LABX-0039-PALM)the Ministry of Science and Higher Education of the Russian Federation(Agreement with Joint Institute for High Temperatures RAS No.075-15-2020-785)G.G.acknowledges support from the UK EPSRC(Grant Nos.EP/M022331/1 and EP/N014472/1)。
文摘The interaction between a molecular cloud and an external agent(e.g.,a supernova remnant,plasma jet,radiation,or another cloud)is a common phenomenon throughout the Universe and can significantly change the star formation rate within a galaxy.This process leads to fragmentation of the cloud and to its subsequent compression and can,eventually,initiate the gravitational collapse of a stable molecular cloud.It is,however,difficult to study such systems in detail using conventional techniques(numerical simulations and astronomical observations),since complex interactions of flows occur.In this paper,we experimentally investigate the compression of a foam ball by Taylor–Sedov blast waves,as an analog of supernova remnants interacting with a molecular cloud.The formation of a compression wave is observed in the foam ball,indicating the importance of such experiments for understanding how star formation is triggered by external agents.
基金We acknowledge the support of the LULI technical teams and support from Grant No.E1127 from Region Ile-de-France.S.N.C is supported by the National Science Foundation under Grant No.OISE-1064468This work was partly done within the LABEX Plas@Par project and supported by Grant No.11-IDEX-0004-02 and ANR-17-CE30-0026-Pinnacle from Agence Nationale de la Recherche+2 种基金It has received funding from the European Union's Horizon 2020 Research and Innovation programme under LASERLAB-EUROPE grant agreement No.654148 Laserlab-EuropeThis work has been carried out within the framework of the EUROfusion Consortium and has received funding,through the ToIFE,from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No.633053The views and opinions expressed herein do not necessarily reflect those of the European Commission.This work was also supported in part by JSPS KAKENHI Grant No.15H03758.
文摘The collective interaction between intense ion beams and plasmas is studied by simulations and experiments,where an intense proton beam produced by a short pulse laser is injected into a pre-ionized gas.It is found that,depending on its current density,collective effects can significantly alter the propagated ion beam and the stopping power.The quantitative agreement that is found between theories and experiments constitutes the first validation of the collective interaction theory.The effects in the interaction between intense ion beams and background gas plasmas are of importance for the design of laser fusion reactors as well as for beam physics.
