Laser blow-off lithium beam probing with high temporal resolution for edge plasma diagnostics
Abstract
Laser blow-off neutral lithium beam probing with high temporal resolution has been developed to measure edge electron density profiles in a plasma. A new electron density reconstruction method, taking account of the transport of a laser blow-off beam in the plasma, improved the accuracy of the density measurement. The use of a camera system with gate function makes it possible to measure the density profile with high temporal resolution of approximately 10 to 50 microseconds. The optimum condition for shuttering timing and period to observe Li I emission profile is discussed from the viewpoints of the beam penetration into the plasma and the accuracy of measurement. A rapid temporal evolution of edge electron density profile during the limiter biasing in a small tokamak HYBTOK-II is successfully obtained by this system.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- April 1993
- Bibcode:
- 1993STIN...9427701S
- Keywords:
-
- Density Measurement;
- Electron Density Profiles;
- Laser Spectroscopy;
- Neutral Beams;
- Plasma Density;
- Plasma Diagnostics;
- Plasma Layers;
- Atomic Beams;
- Beam Injection;
- Emission Spectra;
- Lithium;
- Neutral Atoms;
- Temporal Resolution;
- Tokamak Devices;
- Lasers and Masers