An ionization instability is any one of a category of plasmainstabilities which is mediated by electron-impact ionization. In the most general sense, an ionization instability occurs from a feedback effect, when electrons produced by ionization go on to produce still more electrons through ionization in a self-reinforcing way.
Ionization instabilities have been seen in such plasma physics apparatus as glow discharges,[1][2] Penning discharges,[3]magnetic nozzles,[4][5][6] and MHD generators.[7][8][9] Ionization instabilities may occur in magnetized or unmagnetized[10] plasma. They occur mostly when the plasma is relatively cold and only partially ionized, so that there is a lot of neutral gas mixed in with the plasma.
^Aanesland, A.; Lieberman, M. A.; Charles, C.; Boswell, R. W. (December 2006). "Experiments and theory of an upstream ionization instability excited by an accelerated electron beam through a current-free double layer". Physics of Plasmas. 13 (12): 122101. Bibcode:2006PhPl...13l2101A. doi:10.1063/1.2398929. hdl:1885/16395. ISSN1070-664X.
^Murakami, Tomoyuki; Okuno, Yoshihiro; Yamasaki, Hiroyuki (9 May 2005). "Suppression of ionization instability in a magnetohydrodynamic plasma by coupling with a radio-frequency electromagnetic field". Applied Physics Letters. 86 (19): 191502. Bibcode:2005ApPhL..86s1502M. doi:10.1063/1.1926410. ISSN0003-6951.