Creation of a multi-centimeter low density plasma channel using high magnetic fields

We will present experimental results that show the formation of a laser produced plasma channel when applying a large external magnetic field. This channel is suitable for guiding laser beams and is directly applicable to wakefield acceleration and short pulse laser amplification. This is accomplished by applying a technique that has been established at the Jupiter Laser Facility; an external magnetic field is used to prevent radial heat transport [D. H. Froula \textit{et.al.}, Phys. Rev. Lett. 98, 135001 (2007)] resulting in an increased temperature gradient. Temporally resolved Thomson-scattering measurements of the electron temperature profile in large magnetic fields show that the heat front, transverse to a high-power laser beam, is slowed resulting in extremely strong local heating. This strong local heating produces a density channel that is measured with interferometry for densities between 10$^{17}$ cm$^{-3}$ to 10$^{19}$ cm$^{-3}$.