Re-creating the physics of astrophysical jets in laboratory experiments

The research outlined in this proposal lies at the border between Plasma Physics and Astrophysics and for the first time addresses experimentally the outstanding issue of how collapsing nebulae are able to launch highly collimated beams of matter. This area has been studied through observations and by numerical simulations for many years but it is our belief that well characterised quantitative experiments will play a decisive role in resolving a number of outstanding scientific issues. The proposed research will strongly advance the development of the novel research area of Laboratory Astrophysics, which seeks to enhance the understanding of the physics governing the behaviour of astrophysical objects via scaled laboratory experiments, combined with computer modelling. This proposal outlines an in-depth programme of research in this rapidly emerging area and focuses on the study of magnetized supersonic plasma jets. These jets will be formed in our MAGPIE plasma facility at Imperial College and will be studied using a variety of diagnostics including the use of intense proton beam imaging where the protons are formed using a short-pulse laser-produced plasma source adjacent to the jet. The use of proton beams as a diagnostic will allow us, for the first time, to diagnose the magnetic field structure within the jets. The understanding of the complex plasma processes involved in the formation and evolution of these jets involving high magnetic fields will, through our large-scale computational models, be transferred to plasma jets which form in a variety of astrophysical situations. Indeed plasma jets are observed in many astrophysical contexts and it is widely believed that magnetic fields play a crucial part in their structure and evolution. Moreover, it was recently suggested that magnetically driven jets play important role in gamma ray bursts and supernova explosions. This proposal will enable a decisive breakthrough in Laboratory Astrophysics, achieved by combining the three key ingredients which are now in place: a) a unique experimental approach allowing for the first time the creation of high Mach number (M>20) magnetically driven plasma jets with magnetic field topology relevant to astrophysical jet models; b) recent developments in laser technology and in plasma diagnostics to provide means for accurate diagnosis of the plasma parameters; c) 3-D MHD simulation codes developed by the laboratory plasma and astrophysics communities that are now mature enough to provide a strong connection between experiment, astrophysical models and observations. The timeliness of this proposal is also underlined by the growing interest in this field internationally with major efforts in USA (Rochester, Livermore, Cornell, San Diego, Reno). The combined expertise of the authors of this proposal and the involvement of international collaborators from Astrophysics community will allow us to create an unprecedented capability for the Laboratory Astrophysics research and provide both breadth and depth to the programme.