LASER STARK SPECTROSCOPE OF 1,1-DIFLUOROETHYLENE $(CH_{2}=CF_{2})$ AT 890 GHz

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 Title: LASER STARK SPECTROSCOPE OF 1,1-DIFLUOROETHYLENE $(CH_{2}=CF_{2})$ AT 890 GHz Creators: Chou, Hans; Davis, L. W.; Johnston, L. H.; Peck, E. R. Issue Date: 1978 Abstract: The 890.761 GHz line of the HCN laser has been used to produce a Stark spectrum In $CH_{2}=CF_{2}$, of natural isotopic composition. The rotational fine structure is well resolved, for both $\Delta M=0$ and $\Delta M=1$ polarizations. The spectrum starts at 1600 V/cm for $\Delta M=1$, and at slightly lower fields for $\Delta M=0$. This resonance was first reported by Duxbury and Jones $^{1}$ who were able to see Stark dependent absorption but could not resolve enough structure to assign the transition. We have established that $\Delta J=1$ by the intensity pattern of M components; that the transition frequency lies several hundred MHz below the laser frequency, by slightly detuning the laser; that the first order Stark effect predominates that $\Delta M= +1$ holds (absorption) for the $\bot$ polarization spectra; and that $\Delta J$ probably is $48 \leftarrow 47$, by counting Stark components. Here the uncertainty is that extrapolation is required, since the $\Delta M=0$ spectra start out with very low intensity. We hope to be able to make a complete assignment, by calculating energy levels and Stark coefficients for various J and $K_{a},\; K_{c}$ assignments. Lines for a second transition start at about 5500 V/cm, in both polarizations. This transition is also for a high J value, $J>40$, and $\Delta J=1$. This transition lies above the laser frequency. References for rotational and distortion constants for $CH_{2}=CF_{2}$ are given $below^{2,3}$ URI: http://hdl.handle.net/1811/10451 Other Identifiers: 1978-RA-01