Open AccessLaser wakefield excitation and measurement by femtosecond longitudinal interferometry
Author(s) -
C. W. Siders,
Sylvie Blanc,
D. Fisher,
T. Tajima,
M. C. Downer,
A. Babine,
A. N. Stepanov,
A. M. Sergeev
Publication year - 1996
Language(s) - English
Resource type - Reports
DOI - 10.2172/238564
Subject(s) - atomic physics , plasma , interferometry , physics , laser , femtosecond , ponderomotive force , electron density , amplitude , ionization , ultrashort pulse , langmuir probe , optics , plasma diagnostics , plasma oscillation , excitation , ion , nuclear physics , quantum mechanics
Plasma density oscillations (Langmuir waves) in the wake of an intense (I{sub peak} {approximately} 3 {times} 10{sup 17}W/cm{sup 2}) laser pulse (100 fs) are measured with ultrafast time resolution using a longitudinal interferometric technique. Phase shifts consistent with large amplitude ({delta}n{sub e}/n{sub e} {approximately} 1) density waves at the electron plasma frequency were observed in a fully tunnel-ionized He plasma, corresponding to longitudinal electric fields of {approximately} 10 GV/m. Strong radial ponderomotive forces enhance the density oscillations. As this technique utilizes a necessary component of any laser-based plasma accelerator, it promises to be a powerful tool for on-line monitoring and control of future plasma-based particle accelerators