Far infrared laser magnetic resonance spectroscopy
Abstract
The principles and techniques of laser magnetic resonance (LMR) spectroscopy of gas-phase chemical species in the far infrared range are discussed. Similarities between LMR and gas-phase electron paramagnetic resonance are pointed out, along with the differences in molecular or atomic levels probed (rotational or fine-structure levels rather than magnetic sublevels) and consequent differences in wavelength range employed (infrared rather then microwave). The 25 free radicals detected thus far by FIR LMR spectroscopy are indicated, and the detections of CH and CCH, which occur in the interstellar medium, and C and CH2, which will probably be discovered there, are considered in detail. The use of a longitudinal rather than a transverse magnetic field in a laser cavity to permit LMR observations of a molecular ion is also pointed out, and advantages of the technique for the detection of interstellar species based on determination of their rest wavelengths are indicated.
- Publication:
-
In: Interstellar molecules; Proceedings of the Symposium
- Pub Date:
- 1980
- Bibcode:
- 1980im...symp..239E
- Keywords:
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- Far Infrared Radiation;
- Infrared Lasers;
- Interstellar Gas;
- Laser Spectroscopy;
- Magnetic Resonance;
- Electron Transitions;
- Free Radicals;
- Gas Analysis;
- Laser Cavities;
- Molecular Relaxation;
- Instrumentation and Photography