Upgrade of far-infrared laser-based Faraday rotation measurement on MST
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095 (United States)
Recently, the far-infrared (FIR) laser ({lambda}{sub 0}=432 {mu}m) Faraday rotation measurement system on MST has been upgraded. The dc flowing-gas discharge CO{sub 2} pump laser is replaced by a rf-excited, sealed CO{sub 2} laser at 9.27 {mu}m (GEM select 100, Coherent Inc., Santa Clara, CA), which is subdivided equally into three parts to simultaneously pump three FIR cavities. The total infrared pump power is approximately 80 W on the 9R(20) line required to pump the formic acid molecule. Each FIR cavity produces {approx}12 mW, sufficient for 11 simultaneous chord interferometry-polarimetry operations. Three key issues [(1) conservation of circularly polarized wave, (2) colinearity of two probe waves, and (3) stability of intermediate frequencies between lasers] affecting the Faraday rotation measurement have been resolved experimentally.
- OSTI ID:
- 22058664
- Journal Information:
- Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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