Abstract Details
Visualization of laser-driven plasma bubble accelerators by frequency-domain shadowgraphy
Author: DONG PENG
Requested Type: Oral Only
Submitted: 2009-04-20 10:50:03
Co-authors: C. MCGUFFEY, S. REED, N. MATLIS, T. MATSUOKA, V. CHVYKOV, G. KALINTCHENKO, V. YANOVSKY, A. MAKSIMCHUK,K. KRUSHELNICK, W.P. LEEMANS, A. YI, S. KALMYKOV, G. SHVETS,M.C.DOWNER
Contact Info:
University of Texas at Austin
1 University Station C1600
Austin, TX 78712-0
United States
Abstract Text:
We report single-shot shadowgraphic imaging of electron density bubble produced in the wake of a relativistically intense laser pulse traversing a 1.7mm long atmospheric density helium gas jet. The high refractive index bubble embedded in fully ionized plasma strongly refracts a portion of the light of a co-propagating chirped probe pulse, projecting a characteristic shadow pattern onto a virtual screen at the exit plane of the gas jet. This virtual image is relayed to a spectrometer to convert frequency chirp to temporal information. Detailed features of the shadowgraphic bubble images --their transverse and longitudinal dimensions and shape, their appearance above a threshold plasma density n_e~10^19 cm^-3 and drive laser intensity I~10^18 W/cm^2, and their correlation with efficient production of a relativistic electron beam with a quasi-monoenergetic component-are in good agreement with particle-in-cell simulations of plasma bubble formation and probe refraction. The result open an important plasma accelerator structure to direct, detailed, immediate experiment view, thus benchmarking and complementing computer simulations, heretofore the sole source of detailed knowledge of such structures.
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