Collective Thomson scattering measurements of electron feature using stimulated Brillouin scattering in laser-produced plasmas

Collective Thomson scattering (CTS) has been applied to laser-produced plasmas with Gekko XII HIPER laser facility. A scheme of stimulated Brillouin scattering (SBS) has been used in CTS measurements for the first time. Utilizing SBS shortens the probe pulse, which increases the scattered power, and thus collected scattered signal of CTS. Therefore, a lower energy probe laser can be used for given background emission levels to avoid probe heating, which is crucial for plasmas with low electron temperature. Both electron and ion features of CTS have been successfully detected by using the SBS technique. The spatial profile of electron density, temperature, and drift velocity have been estimated in an ablation plasma. In addition to the local measurements with CTS, a global structure of plasmas has been obtained with optical imaging of the self-emission of plasmas and the interferometry. In the aspects of drift velocity and plasma density, the local and global information are in good agreement.