This award from the CRIF-ID program will allow Stephen Cooke in the Department of Chemistry at the University of North Texas to fully characterize and improve a cavity based, time domain, Fourier transform rotational spectrometer capable of recording spectral transitions below 1 GHz. It will also implement a low frequency fast passage version of the experiment to enable rapid location of spectral features. The availability of such an instrument is of considerable interest in regard to: 1. The geometric and electronic structural characterization of larger and/or heavier chemical species than can be routinely studied with high resolution, time domain techniques. 2. Synchronizing laboratory based measurements and radio-astronomy measurements in the region of 20 cm and above. The availability of a low frequency instrument will also aid in the laboratory detection of large molecules that may exist in the interstellar medium.
Fourier transform rotational (microwave) spectrometers measure transitions between rotational energy levels of molecules in the gas phase. These spectra can be analyzed to obtain insight on the arrangment of the atoms in the species under study, in essence information on its structure. Structural information is important for understanding chemical and biochemical properties and reactivity. This instrument development project will be carried out by graduate and undergraduate students who will gain skills in the design and construction of sophisticated state-of-the-art instrumentation.