Hp. Wagner et al., INSTABILITIES IN MPD THRUSTER FLOWS - 1 - SPACE-CHARGE INSTABILITIES IN UNBOUNDED AND INHOMOGENEOUS PLASMAS, Journal of physics. D, Applied physics, 31(5), 1998, pp. 519-528
For a few years, the study of magnetoplasmadynamic instabilities has r
eceived increased attention because they may explain the so-called 'on
set' phenomena which limit the efficiency and, thus, the use of coaxia
l plasma accelerators in space propulsion and other applications. A sy
stematic investigation of instabilities in magnetoplasmadynamic flows
was initiated at the Institut fur Raumfahrtsysteme in 1987. Among othe
r instabilities, a particular one with the characteristics of the spac
e charge instability was found. This instability had until then been k
nown to occur only in finite gas discharge geometries. It will be show
n in this paper that, in the presence of gradients of the flow variabl
es, space charge instabilities can also appear in unbounded plasmas. T
he conditions for their development and growth are determined and disc
ussed.