Laser intracavity absorption as a plasma diagnostic aid
Trace levels of lithium are detected on 100 ..mu..sec timescales using an electrooptically tuned cw dye laser, in conjunction with a high resolution 0.03 A spectrometer/optical multichannel analyzer. The spectra of Li/sup 7/ resonance lines at 6708 A are analyzed for their Zeeman splitting patterns, after unfolding the effects of intracavity absorption (ICA) on the lineshape. For these timescales, a sensitivity to approx.1 x 10/sup 7/ lithium atoms/cc at a level of ..delta..I/I approx.10% has been observed, corresponding to enhancement factors over single pass absorption of approx.1000X. Intracavity enhancement of the line structure in the wings of the line, and a weak blue shift asymmetry have also been observed, but always in the presence of a central absorption feature. The 0.1 A instantaneous laser linewidth is usually scanned over a 1 A range, at frequencies up to 30 kHz. Ultimately this detection system will enclose a hot, dense fusion plasma ... intersecting an 80 keV, 10 mA neutral lithium beam to probe the plasma internal magnetic field structure, in a non-intrusive fashion.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 5403096
- Report Number(s):
- LA-UR-85-2669; CONF-8509127-2; ON: DE85015741
- Resource Relation:
- Conference: 2. international symposium on laser aided plasma diagnostics, Culham, England, 10 Sep 1985; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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