Current density fluctuations and ambipolarity of transport

The fluctuation in the plasma current density is measured in the MIST reversed field pinch experiment. Such fluctuations, and the measured radial profile of the k spectrum of magnetic fluctuations, supports the view and that low frequency fluctuations (f ) demonstrates that radial particle transport from particle motion parallel to a fluctuating magnetic field is ambipolar over the full frequency range

High-power ion-cyclotron heating on the levitated octupole

Experiments are underway in the Wisconsin Levitated Toroidal Octupole to create hot, dense plasmas to facilitate the study of ..beta.. limits and related phenomena such as Pfirsch-Schlueter and bootstrap currents. The question of ballooning mode instability limits on ..beta.. = 8 ..pi..nk(T/sub i/+T/sub e/)/B/sup 2/ is of general importance for all toroidal systems, and ICRF heating should permit study of high ..beta.. plasmas with lower collisionality and smaller gyroradii than those of the high ..beta.. gun-injected plasmas currently under study in the Octupole. To these ends we are developing sources capable of delivering 4 MW to the plasma (1.5 MW coupled to the plasma to date, the rest under development)

Ddt and pcbs in sediments of the venice gulf

The concentrations of DDT and PCBs in surface sediments collected in the Gulf of Venice are reported. The contribution of the lagoon and of the rivers to sea sediment contamination is discussed. Fresh waters reaching the sea through the lagoon or directly from rivers are responsible for relatively high ?DDT concentrations. The Porto Marghera industrial zone located in the inner border of the lagoon is probably the main PCB source. Two transport mechanisms have been identified: mobilization of suspended solids by tidal movements and direct dumping of industrial tailing and/or dredged materials from the lagoon canals. © 1983 Taylor & Francis Group, LLC