27 research outputs found
Plasma parameters and electron energy distribution functions in a magnetically focused plasma
Spatially resolved measurements of ion density, electron temperature, floating potential, and the electron
energy distribution function (EEDF) are presented for a magnetically focused plasma. The measurements
identify a central plasma column displaying Maxwellian EEDFs at an electron temperature of about 5 eV
indicating the presence of a significant fraction of electrons in the inelastic energy range (energies above
15 eV). It is observed that the EEDF remains Maxwellian along the axis of the discharge with an increase
in density, at constant electron temperature, observed in the region of highest magnetic field strength.
Both electron density and temperature decrease at the plasma radial edge. Electron temperature isotherms
measured in the downstream region are found to coincide with the magnetic field lines.The authors would like to acknowledge support from the
Australian Research Council through a Future Fellowship
(FT100100825)
SDS-PAGE-Based Quantitative Assay for Screening of Kidney Stone Disease
Kidney stone disease is a common health problem in industrialised nations. We developed a SDS-PAGE-based method to quantify Tamm Horsfall glycoprotein (THP) for screening of kidney stone disease. Urinary proteins were extracted by using ammonium sulphate precipitation at 0.27 g salt/mL urine. The resulted pellet was dissolved in TSE buffer. Ten microliters of the urinary proteins extract was loaded and separated on 10% SDS-PAGE under reducing condition. THP migrated as single band in SDS-PAGE. The assay reproducibility and repeatability were 4.8% CV and 2.6% CV, respectively. A total of 117 healthy subjects and 58 stone patients were tested using this assay, and a distinct cut-off (P < 0.05) at 5.6 μg/mL THP concentration was used to distinguish stone patients from healthy subjects. The sensitivity and specificity of the method were 92.3% and 83.3%, respectively
Vibrationally resolved electron-impact excitation cross sections for singlet states of molecular hydrogen
We present calculations of vibrationally resolved cross sections for excitation of the , B 1 Σ+u, C 1IIu, B’ 1Σ+u, D 1IIu, and E, F 1Σ+8 electronic states of molecular hydrogen. Here we apply the adiabatic nuclei convergent close-coupling method formulated in two-center prolate spheroidal coordinates. We find significant disagreement with previous calculations, where available
Interpretations of the impact of cross-field drifts on divertor flows in DIII-D with UEDGE
Simulations using the multi-fluid code UEDGE indicates that, in low confinement (L-mode) plasmas in DIII-D, poloidal projection of the ionization driven flows dominate poloidal particle flows in the divertor near the divertor plates, whereas E × B drift flows dominate the radial particle flows. In contrast, in high confinement (H-mode) conditions E × B drift flows dominate both poloidal and radial particle flows in the divertor in the vicinity of the strong gradient region near the separatrix. UEDGE indicates that the toroidal C2+ flow velocities in the divertor plasmas are mainly entrained within 30% to the background deuterium flow in both L- and H-mode plasmas in the plasma region where the CIII 465 nm emission is measured. Therefore, UEDGE indicates that the Doppler Coherence Imaging Spectroscopy (CIS), measuring the toroidal velocity of the C2+ ions, can provide insight to the deuterium flows in the divertor. Parallel-to-B velocity dominates the toroidal divertor flow; direct drift impact being less than1%. Toroidal divertor flow is predicted to reverse when the magnetic field is reversed. This is explained by the parallel-B flow towards the nearest divertor plate corresponding to opposite toroidal directions in opposite toroidal field configurations.Peer reviewe
Impact of drifts on divertor power exhaust in DIII-D
Radiative divertor experiments and 2D fluid simulations show strong impact of cross-field drifts on the low field side (LFS) divertor target heat flux and volumetric radiation profiles when evolving to detached conditions in DIII-D high confinement mode (H-mode) plasmas with forward and reversed toroidal field configurations. In both field configurations, the peak heat flux is reduced by about a factor of 2 in detachment by D 2 -injection and by factor of 3 – 4 in detachment by N 2 -injection. Operating with the B × ∇B-drift towards the X-point (fwd. BT), the LFS divertor radiation front is observed to shift step-like from the target to near to the X-point at the onset of detachment. In contrast, operating with the B × ∇B-drift away from the X-point (rev. BT), the radiation front is observed to remain closer to the target plate and to be radially shifted towards the far SOL. These phenomena occur with detachment induced both with N 2 - and D 2 -injection. The step-like detachment onset is consistent with recently published theory of the role of poloidal E × B-drift in the private flux region in driving highly non-linear detachment onset in fwd. BT [22].Peer reviewe