A Multipass System for Thomson Scattering Diagnostic with Multipulse-Lasing

Abstract

A Thomson scattering system with multipasses was set up for diagnostics on the tokamak NOVA‐UNICAMP. As the laser beam comes back to the ruby laser operating in Q‐switched mode, we observed the presence of multipulses, increasing the effective laser pulse energy by a factor of approximately 6.5 with operation at 18 passes. Much better results can be obtained by improving the quality of the optical surfaces. Measurements of the pulse characteristics and the results obtained are presented and discussed.