arXiv subjects
Publications and source records attributed to Robert Farrenq.
A TiCl_4/He plasma is observed by high resolution double-modulation FTS using concentration-modulation as a selective detection method. Analysis of the C ^4Δ- X ^4 ΦΔv=0 transitions of ^48Ti^35Cl reveals perturbations affecting the C ^4Δ_{1/2} sub-state.
The spectral dynamics of a mid-infrared multimode Cr^2+:ZnSe laser located in a vacuum sealed chamber containing acetylene at low pressure is analyzed by a stepping-mode high-resolution time-resolved Fourier transform interferometer. Doppler-limited absorption spectra of C_2H_2 in natural isotopic abundance are recorded around 4000 cm^-1 with kilometric absorption path lengths and sensitivities better than 3 10^-8 cm-1. Two cold bands are newly identified and assigned to the n_1+n_4^1 and n_3+n_5^1 transitions of ^12C^13CH_2. The n_1+n_5^1 band of ^12C_2HD and fourteen ^12C_2H_2 bands are observed, among which for the first time n_2+2n_4^2+n_5^-1.
Velocity-modulation Fourier transform emission spectra from a N_2O/He discharge plasma recorded between 1 and 5.5 $μ$m are described. Surprisingly, they show Doppler-shifted lines for the E ^2 Σ^+ - D ^2 Σ^+, C ^2 Π- A ^2 Σ^+, and D ^2 Σ^+ - A ^2 Σ^+ Rydberg-Rydberg rovibronic transitions of the nitric oxide neutral molecule. These polarity-dependent Doppler-shifts are those of positively charged particles. Vibration-rotation lines of NO and transitions from other neutral molecules like N_2 are also present in the spectra with comparable intensities and remain unshifted. Experimental investigations and possible explanations are discussed.