Probe measurements of low-frequency plasma potential and electric field fluctuations in a magnetized plasma
2002 (English)In: Physics of Plasmas, ISSN 1070-664X, Vol. 9, no 10, 4135-4143 p.Article in journal (Refereed) Published
A system of two cylindrical probes aligned along the magnetic field, and equipped with insulating end plugs, is proposed for measurement of low-frequency fluctuations of the electrostatic field in a magnetized plasma. It is demonstrated by modeling and experiments that the plug probe floats close to the plasma potential. The electric field component in a given direction is obtained by subtracting the plasma potentials obtained on two spatially separated plug probes. The probe system is applied to low-frequency electrostatic fluctuations in a simple magnetized torus, and reveals the presence of global oscillations, large scale propagating structures (m=1 modes), and developed turbulence with power-law spectra. Two different mode branches for the fluctuations are identified by comparing results from plug probes with results from conventional probes. Sources of errors arising from applying floating potential of conventional probes for electric field measurements are pointed out and discussed.
Place, publisher, year, edition, pages
2002. Vol. 9, no 10, 4135-4143 p.
electrostatic fluctuations, temperature-fluctuations, toroidal plasma, heat-transport, tokamak
IdentifiersURN: urn:nbn:se:kth:diva-21911ISI: 000178095700007OAI: oai:DiVA.org:kth-21911DiVA: diva2:340609
QC 201005252010-08-102010-08-10Bibliographically approved