High-temperature Stark and radio-frequency-microwave double-resonance microwave spectrometer
Abstract
A high-temperature microwave spectrometer has been constructed for the study of hot corrosive gases. The absorption cell consists of a 213-cm X-band copper waveguide which is heated along roughly 130 cm of its length. A thin nickel strip held taut by stainless-steel posts at either end of the waveguide serves as the Stark septum. The sample chamber is coupled to the Stark cell midway along its length by a slip joint formed from two concentric tubes. This design ensures a long effective absorption path length and minimizes sample consumption. The hot cell is used in conjunction with an HP 8400C microwave spectrometer source which has been interfaced to a small computer for data acquisition, storage, and retrieval. The successful operation of the spectrometer has been demonstrated with KOH vapor at 580 °C. The J=2←1 transitions of a number of vibrational states of monomeric KOH have been observed in the region of 32.8 GHz. The observed signal-to-noise ratio of these transitions indicates that the sensitivity compares favorably to spectrometers which have been used to observe higher J transitions in the submillimeter region. Radio-frequency-microwave double resonance techniques have been demonstrated for the first time in a high-temperature Stark cell by observing the J=2←1 l-doublet transitions in the (011O) state of KOH.
- Publication:
-
Review of Scientific Instruments
- Pub Date:
- June 1987
- DOI:
- 10.1063/1.1139586
- Bibcode:
- 1987RScI...58..979R
- Keywords:
-
- High Temperature Gases;
- Hot Corrosion;
- Microwave Spectrometers;
- Numerical Control;
- Radio Frequencies;
- Stark Effect;
- Microwave Resonance;
- Potassium Hydroxides;
- Submillimeter Waves;
- Instrumentation and Photography