Local laser superheating due to quenching determined by degenerate four-wave-mixing and absorption thermometry
✍ Scribed by M. Motzkus; G. Pichler; K.L. Kompa; P. Hering
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 695 KB
- Volume
- 257
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
We used degenerate four-wave-mixing (DFWM) spectroscopy to measure the rotational distribution of transient formed Nail molecules in the Na(3p)-H 2 collision system applying a recently developed new method for the correct consideration of the transition dipole moment. Considering the Nail molecule as a thermometric species, we found high rotational temperatures differing significantly from the oven temperature by up to 80%. For comparison the revealed temperatures were also determined with linear absorption measurements giving excellent agreement between the two methods. The increased temperatures are explained by a spatially localized heating mechanism which is caused by kinetic energy transfer between Na(3p) and H 2. A rate equation model, which includes quenching and reaction processes, agrees satisfactorily with all types of chosen parameters, including different sodium excitations as well as different cell temperatures.