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Introduction
Ion acceleration MeV-proton beam imaging
of relativistic plasmas
Herein a proton beam, generated by one laser, probes
time resolved field structures and dynamics in a plasma generated
by a second laser. Hence, laser acceleration of protons acts both
as a tool and a subject of investigation itself.
MBI is part of the national DFG TRANSREGIO TR18 TR18
collaboration, comprising the major laboratories in the field of
relativistic plasma dynamics. There, laser driven ion acceleration
is being studied over a wide range of laser parameters, with applications
in plasma physics, astrophysics, and nuclear physics.
Within the first period of TR18 (ended in June 2008) the two MBI
high field lasers (a 1ps, ~10 J CPA glass laser and the 40 fs, ~1
J Ti:Sa laser) were synchronized with 1ps accuracy of the two 10
Hz front-end systems. This setup provided the experimental base
for novel imaging experiments which had been realized in collaboration
experiments. The temporal evolution of different acceleration fields
has been analyzed from data obtained with a developed streak deflectometry
setup ("proton streak camera"). New target systems as
e.g. mass-limited and ultra-thin foil targets come now into the
focus of ion acceleration research because higher energy transfer
efficiency and as already demonstrated at MBI the production of
quasi “mono-energetic” ion beams is important for the
further advancement of the field. Proton imaging experiments with
laser irradiated isolated targets (water droplets) experiments showed
asymmetries in the field geometry which were analyzed with collaboration
partners.
Experimental possibilities have been significantly
enhanced with the upgrade of the high field laser system to a two
arm (100 TW, and >30 TW) Ti:Sa laser system and a newly built
radiation shielded lab area in 2010. Beamline construction and first
experiments in 2011 are devoted to imaging experiments and new acceleration
schemes. The whole installations essential for continuation of the
TR18 research projects which have been approved for the second funding
period (2008 - 2012).
Electron acceleration
The new topic on electron acceleration will start
in 2012. Especially the newly built lab area with radiation shielding
enables now this research. In regard to the analysis of presently
available knowledge and results we will concentrate on staged electron
acceleration schemes. The realization of subsequent acceleration
stages with our two beam laser facility will deal with a research
topic which is emphasized by leading groups in this area. There
is a clear aim – the realization of electron bunches with
GeV kinetic energies and femtosecond duration. If such pulses can
be produced stable a new generation of laser based electron accelerators
can serve for the emission of brilliant x-rays which are applied
in many fields.
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