Observations and analysis of magnetic fluctuations in the Maryland centrifugal experiment

Date

2008

Author

Choi, S.
Guzdar, P. N.
Case, A.
Ellis, R.
Hassam, A. B.
Lunsford, R.
Teodorescu, C.
Uzun Kaymak, İlker Ümit

Metadata

Show full item record

Item Usage Stats

146
views

0
downloads

Initial results from magnetic probes on the Maryland Centrifugal eXperiment (MCX) [R. F. Ellis , Phys. Plasmas 8, 2057 (2001)] provide details of the propagation and azimuthal mode structure of magnetic fluctuations in the edge region. Magnetic coils placed azimuthally along the edge measure changes in the axial magnetic field during the time history of the plasma discharge. The eight evenly spaced coils can resolve azimuthal modes up to m=3. The plasma rotates azimuthally in MCX due to an applied radial electric field. Using a variety of different analysis of the data, it is inferred that the magnetic fluctuations are dominantly convected by the plasma rotation for several rotation periods before significant decorrelation. These findings help to identify the modes at the edge and indicate that there are a few low mode numbers that are dominant during the discharge. Also, the speed of rotation of the modes is found to change dramatically from the High Rotation (HR) state to a low rotation ordinary (O) state, consistent with a corresponding change in the plasma load voltage. The fluctuation spectrum becomes dominated by a single mode after the transition.

Subject Keywords

Rotatıng plasmas, Mode

URI

https://hdl.handle.net/11511/28125

Journal

Physics of Plasmas

DOI

https://doi.org/10.1063/1.2903053

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Observations and Simulations of Magnetic Fluctuations in MCX Uzun Kaymak, İlker Ümit; Ellis, R. F.; Hassam, A. B.; Teodorescu, C. (Springer Science and Business Media LLC, 2009-09-01) Recently magnetic fluctuations in the Maryland centrifugal experiment (MCX) have been measured by an azimuthal array of 16 probes in the edge region of the plasma. A detailed analysis indicates that there is primarily a convection of m = 2 fluctuations by the azimuthally rotating plasma. However, the frequency spectrum of this mode is broad and is almost of the same order as the frequency. Furthermore, bicoherence analysis indicates dominant nonlinear interaction between m = 2 and a low frequency m = 0 mode...
Analysis and modeling of edge fluctuations and transport mechanism in the Maryland Centrifugal Experiment Uzun Kaymak, İlker Ümit; Clary, R.; Ellis, R. F.; Hassam, A. B.; Teodorescu, C. (AIP Publishing, 2008-11-01) The Maryland Centrifugal Experiment [R. F. Ellis , Phys. Plasmas 12, 055704 (2005)] is a mirror machine designed to have a plasma axially confined by supersonic rotation and dominantly interchange stable by the radial shear in the azimuthal velocity. Nevertheless, residual fluctuations still persist. To investigate the presence of such fluctuations, an azimuthal array of 16 magnetic pickup coils at the edge region of the plasma has been employed. A comprehensive analysis of the magnetic fluctuations reveals...
Study of high mass Higgs using pp -> qqH Yildiz, HD; Zeyrek, Mehmet Tevfik (2003-08-01) The observability of the Higgs signal in the mass range of 200-800 GeV is investigated in the weak boson fusion channel at the CMS experiment at LHC. The weak boson fusion channel is characterized by two final state jets at large pseudorapidity. The forward calorimeter plays a key role in detecting these jets. The significant signals are obtained for H --> WW --> lvjj, H --> ZZ --> lljj and H --> ZZ --> llvv. Importance of the forward jet tagging and the central jet veto is emphasized to extract the signal ...
Investigations of pulsational properties and evolution of propagation diagram in some delta Scuti star models Kiziloglu, N; Kirbiyik, H; Civelek, R (World Scientific Pub Co Pte Lt, 2003-07-01) An investigation on the subject of evolution of propagation diagrams and obtaining the theoretical frequency spectrum of some delta Scuti star models with masses around 2 M-circle dot has been presented. The variations of some eigenfunctions throughout the star, the variation of omega(2) with logT(e) and the distribution of nodes of eigenfunctions of some modes along with the evolution of the star have been plotted and examined. For the models at the ZAMS phase, pure acoustic modes in the outer stellar laye...
Measurement of the centrality dependence of J/psi yields and observation of Z production in lead-lead collisions with the ATLAS detector at the LHC Aad, G.; et. al. (Elsevier BV, 2011-03-14) Using the ATLAS detector, a centrality-dependent suppression has been observed in the yield of J/psi mesons produced in the collisions of lead ions at the Large Hadron Collider. In a sample of minimum-bias lead-lead collisions at a nucleon-nucleon centre of mass energy root s(NN) = 2.76 TeV, corresponding to an integrated luminosity of about 6.7 mu b(-1), J/psi mesons are reconstructed via their decays to mu(+)mu(-) pairs. The measured J/psi yield, normalized to the number of binary nucleon-nucleon collisio...

Citation Formats

S. Choi et al., “Observations and analysis of magnetic fluctuations in the Maryland centrifugal experiment,” Physics of Plasmas, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/28125.