New Techniques in Microwave Spectroscopy
Published Online: 15 SEP 2011
Copyright © 2011 John Wiley & Sons, Ltd. All rights reserved.
Handbook of High-resolution Spectroscopy
How to Cite
Shipman, S. T. and Pate, B. H. 2011. New Techniques in Microwave Spectroscopy. Handbook of High-resolution Spectroscopy. .
- Published Online: 15 SEP 2011
We discuss the design principles and performance of a true broadband chirped-pulse Fourier transform microwave spectrometer capable of operation from 800 MHz to 18.5 GHz. This spectrometer utilizes recent advances in high-speed digital electronics to both directly generate linear frequency sweeps spanning more than 10 GHz and to directly digitize the molecular free induction decay (FID). Signal averaging is performed in the time domain to improve the signal-to-noise ratio. This spectrometer has a number of capabilities that are well suited for studies on large-molecule systems, including the ability to perform multiplexed Stark effect measurements and selective-excitation microwave double-resonance measurements. These characteristics are demonstrated using the molecule 1,2,2,2-tetrafluoroethyl difluoromethyl ether (C3H2F6O, molecular weight 168 g mol−1, also known by its trade names of suprane or desflurane) as an example. The simultaneous use of multiple-pulsed nozzles as well as the acquisition of multiple FIDs per valve pulse is also demonstrated in the context of strategies for increasing spectrometer sensitivity by 2 orders of magnitude.
- chirped pulse;
- large-molecule spectroscopy;
- selective excitation;
- Stark effect;
- Fourier transform microwave spectroscopy