Sub-Terahertz High-Sensitivity High-Resolution Molecular Spectroscopy With a Gyrotron

Pure rotational R(0) and R(1) lines of CO in Ar baths: experimental broadening, shifting and mixing parameters in a wide pressure range versus ab initio calculations

“…The radioacoustic spectrometer 45–48 was used for recording the R(0) and R(1) line profiles in the pressure range from several dozen of mTorr up to several torr at room temperature (the cell temperature was stabilized by using the active thermostat within ∼0.5 K). These recordings contained 201 or 151 frequency points, but due to the high stability of temperature and pressure in the short 10 cm gas cell (which is much simpler to implement than in the 2 m video cell), multiple recordings were performed with averaging of the recorded spectra.…”

Russian Gyrotrons: Achievements and Trends

“…Recently, the phase-lock loop stabilized gyrotron was used in experiments for recording characteristic lines in pure gases and gas mixtures by the methods of RAD spectroscopy [33], [34].…”

“…IAP has achieved significant progress in the development of mode conversion methods [46]. Quasi-optical mode converters transformers are capable of converting such complex modes as ТЕ 25,10 , ТЕ 28,12 , and ТЕ 34,19 to Gaussian beams (eigenmodes of mirror waveguides) with an efficiency of 95-97% ( Fig. 7), while ensuring that the structures formed in the waveguide cross sections are optimal for this or that assembly unit, e.g., for the output window of the gyrotron [47].…”

CO-Ar collisions: ab initio model matches experimental spectra at a sub percent level over a wide pressure range

“…A spectrometer with radioacoustic detection of absorption (RAD) [33][34][35][36] was used for line profile studies in the pressure range 0.1-2 Torr (Fig. 1B).…”