Time-resolved imaging of millimeter-waves using recombination continuum of cesium emitted by a slab of the Cs-Xe DC discharge

Design and production of microwave sources and transmission lines, microwave nondestructive imaging in opaque media, as well as other scientific, industrial, and medical applications require convenient real-time methods for recording the spatial distribution of microwave intensity (S.O. Kuznetsov and I. Malygin, Int. J. IR and MM Waves, vol. 12, no. 11, pp. 1241-1252, 1991; J.-C. Bolomey, IEEE Trans. Microwave Theory Tech., vol. 37, no. 12, pp. 2109-2117, 1989). In this paper we discuss the method of microwave beam imaging by the blue recombination continuum of cesium emitted by a slab of the positive column (PC) of a Cs-Xe DC discharge. The blue recombination continuum of cesium (optical wavelength shorter than 500 nm) originates from radiative recombination of electrons and cesium atomic ions into the 6P state of cesium (Y.P. Raizer, Gas Discharge Physics, ch. 9, Springer, Berlin, 1991; J.M. Wetzer, Physica C, vol. 123, pp. 247-256, 1984; L. Agnew and W.H. Reichelt, J. Appl. Phys., vol. 39, no. 7, pp. 3149-3155, 1968). We anticipate that this sensitive imaging method can be used for real-time recording of the spatial distribution of microwave intensity.