Pierre Pinson

Infrared and microwave high-resolution spectrum of the ν3 band of ozone

Abstract The vibration-rotation band ν 3 of ozone has been recorded with a high-resolution (0.012 cm −1 ) spectrometer, and microwave absorption spectra of ozone have been identified in the excited vibrational states (100) and (001). A strong Coriolis interaction has been observed. More than 1200 spectral lines have been identified in the ν 3 band, using a Watson-type Hamiltonian, including all the sextic centrifugal distortion terms. Band constants and an atlas listing line wavenumbers, intensities, and assignments are given, from 1007 to 1072 cm −1 . It is shown that transitions with high values of the quantum numbers K −1 (≥11) contribute to significant absorption.

Emission spectrum of CO2 in the 9.6 μm region

Abstract The emission spectrum of 12C16O2 in the 9.6 μm region has been observed with a high resolution spectrometer. The 000-0200 transition appears with a high intensity. Some additional transitions have also been observed and effective rotational constants for the corresponding bands have been calculated. Because of the overlapping of some “hot” lines with the principal ones, care has to be taken in using the 0001–0200 transition as reference for calibration of high resolution spectra.

High Resolution Infrared Spectrometer in the 8–10-μm Range

A double pass SISAM interferometer is presented. Its resolving power is close to 0.011 cm(-1) Accurate q(u) constants of 11(1)0 and 03(1)0 levels of N(2)O are calculated using the first spectra recorded.

Analysis of the high resolution spectrum of the fundamental bandsv2 andv5 of12CH3F and their interactions

Thev2(A1) andv5(E) fundamental vibration-rotation bands of12CH3F have been recorded under high resolution (0.015 to 0.020 cm−1) in the spectral range of 1460 cm−1. About 1100 transitions have been assigned. The Coriolis interaction between v2=1 and v5=1, and the l(2,-1) interaction in v5=1 have been rigorously treated. Sixteen molecular constants have been determined from a least squares analysis. They reproduce the observed data with an overall standard deviation of 0.0037 cm−1.

Emission spectrum of N2O in the 8 μm range

Abstract A spectrum of N 2 O excited by a dc discharge has made possible the observation of 15 bands (type Δ v 1 = 1) in the 8 μm range. Effective constants of the involved levels were determined from a simultaneous least-squares fit of the data.

Passive Q switching by heated CO2

Abstract Passive Q switching using heated CO 2 as a saturable absorber was observed. A kinetic model previously proposed is used to interpret this phenomenon. Our study reveals the important role of rotational and vibrational relaxation mechanisms.

Approaches to dissociation processes of SF6 by one or two T.E.A. CO2 lasers

Abstract We present experimental results on the variation of the SF6 dissociation rate as a function of the frequency and energy of the CO2 T.E.A. laser. We give a possible explanation of dissociation by classical absorption mechanisms involving ΔJ = ±2 transitions, and we present a process that we call “probabilities-crossing mechanism”.