Interferometric density measurement of the gas-filled capillary plasma and its comparison with the Hβ line measurement

Abstract

Electron density in a gas-filled capillary plasma for laser wakefield acceleration is a crucially important parameter for successful acceleration experiment. We measured the electron density by using the interferometric method, and some important plasma parameters such as an on-axis density and a channel depth are characterized with the discharge plasma current. The results from the interferometric method are also compared with the spectroscopic measurement results using the Hβ line for confirming their validity, and a reasonably good argeement is found between them. © 2012 IOP Publishing Ltd and SISSA.