Experimental Studies of Properties of Excited States of Cesium (Rydberg Matter) in the Interelectrode Plasma of a Low-Temperature Thermal to Electric Energy Thermionic Converter

A review is given of experimental work on the study of properties of a condensate of excited states (Rydberg matter) of cesium by electrophysical and optical methods. The work has been performed by the author with colleagues from the SSC RF-IPPE since 2002 up to the present, the results having been published in various domestic scientific editions. The findings are compared with theoretical data of various authors and experimental results of a group of L. Holmlid from the University of Gothenburg (Sweden), the only group except a group of V. Yarygin working in the field of experimental studies of Rydberg matter (RM) of cesium and other alkali metals. A concept is discussed of a practical use of RM in operation of a low-temperature thermal to electric energy thermionic converter (TIC) at the emitter temperature lower than 1,600 K, the collector temperature lower than 700 K, the generalized index of an energy loss in a TIC (so-called barrier index) VB ~1.6 eV.