Plasma turbulence imaging using high-power laser Thomson scattering

The two-dimensional (2D) structure of plasma density turbulence in a magnet ically confined plasma can potentially be measured using a Thomson scatteri ng system made from components of the Nova laser of Lawrence Livermore Nati onal Laboratory. For a plasma such as the National Spherical Torus Experime nt at the Princeton Plasma Physics Laboratory, the laser would form an appr oximate to 10-cm-wide plane sheet beam passing vertically through the chamb er across the magnetic field. The scattered light would be imaged by a char ge coupled device camera viewing along the direction of the magnetic field. The laser energy required to make 2D images of density turbulence is in th e range 1-3 kJ, which can potentially be obtained from a set of frequency-d oubled Nd:glass amplifiers with diameters in the range of 208-315 mm. A las er pulse width of less than or equal to 100 ns would be short enough to cap ture the highest frequency components of the expected density fluctuations. (C) 2001 American Institute of Physics.