B. D. Blackwell
A5022114024- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Time Series Analysis and Forecasting
- Nuclear reactor physics and engineering
- Astronomical Observations and Instrumentation
- Atomic and Subatomic Physics Research
- Astronomy and Astrophysical Research
- Spacecraft and Cryogenic Technologies
- Nuclear Physics and Applications
- Magnetic Field Sensors Techniques
- Astro and Planetary Science
- Dust and Plasma Wave Phenomena
- Particle Accelerators and Free-Electron Lasers
- Algorithms and Data Compression
- Electrohydrodynamics and Fluid Dynamics
- Electromagnetic Launch and Propulsion Technology
- Defense, Military, and Policy Studies
- Photocathodes and Microchannel Plates
Australian National University
2012-2021
Princeton Plasma Physics Laboratory
2015-2021
Ottawa Research and Development Centre
2019
Agriculture and Agri-Food Canada
2000-2019
Oak Ridge National Laboratory
2016-2017
University of Illinois Urbana-Champaign
2017
Max Planck Institute for Plasma Physics - Greifswald
2016
Physikalisch-Technische Bundesanstalt
2016
University of Opole
2016
CEA Cadarache
2016
Abstract The optimized superconducting stellarator device Wendelstein 7-X (with major radius , minor and plasma volume) restarted operation after the assembly of a graphite heat shield 10 inertially cooled island divertor modules. This paper reports on results from first high-performance operation. Glow discharge conditioning ECRH discharges in helium turned out to be important for density edge radiation control. Plasma densities with central electron temperatures were routinely achieved...
Abstract Research on magnetic confinement of high-temperature plasmas has the ultimate goal harnessing nuclear fusion for production electricity. Although tokamak 1 is leading toroidal magnetic-confinement concept, it not without shortcomings and community therefore also pursued alternative concepts such as stellarator. Unlike axisymmetric tokamaks, stellarators possess a three-dimensional (3D) field geometry. The availability this additional dimension opens up an extensive configuration...
After completing the main construction phase of Wendelstein 7-X (W7-X) and successfully commissioning device, first plasma operation started at end 2015. Integral start-up using electron cyclotron resonance heating (ECRH) an extensive set diagnostics have been completed, allowing initial physics studies during operational campaign. Both in helium hydrogen, breakdown was easily achieved. Gaining experience with vessel conditioning, discharge lengths could be extended gradually. Eventually,...
Abstract Fusion energy research has in the past 40 years focused primarily on tokamak concept, but recent advances plasma theory and computational power have led to renewed interest stellarators. The largest most sophisticated stellarator world, Wendelstein 7-X (W7-X), just started operation, with aim show that earlier weaknesses of this concept been addressed successfully, intrinsic advantages persist, also at parameters approaching those a future fusion plant. Here we first physics...
DNA prepared from soil usually contains a brown-tinted inhibitor of the polymerase chain reaction (PCR) which limits sensitivity this technique for specific detection microorganisms. To localize inhibitor, fractions were tested their inhibitory effect on PCR reaction. A highly activity, sufficient to account inhibition typically exhibited by DNA, was found be tightly associated with microorganism fraction. After cell breakage, material became soluble, and not separable standard purification...
H-1 is a three-field period medium-sized heliac (R0 = 1 m, r 0.22 and B0 T) nearing completion at the Australian National University, Canberra, intended for basic plasma physics studies, including finite beta effects, in toroidal confinement systems. Its design allows wide range of “current-free” magnetic configurations to be explored their properties equilibrium stability.
The Magnetized Plasma Interaction Experiment (MAGPIE) is a versatile helicon source plasma device operating in magnetic hill configuration designed to support broad range of research activity and the first stage Materials Diagnostic Facility at Australian National University. Various material targets can be introduced study plasma–material interaction phenomena.
rf power in the lower-hybrid-frequency range is shown to produce plasma of density ${10}^{13}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ small toroidal heliac SHEILA by launching helicon waves. Measurements wave dispersion and mode structure confirm that an m=1 launched inside highly asymmetric confined device. The suggestion main energy-transfer mechanism Landau damping strongly supported experimental data.
The Wendelstein 7-X (W7-X) optimized stellarator fusion experiment, which went into operation in 2015, has been operating since 2017 with an un-cooled modular graphite divertor. This allowed first divertor physics studies to be performed at pulse energies up 80 MJ, as opposed 4 MJ the phase, where five inboard limiters were installed instead of a This, and number other upgrades device capabilities, extension regimes higher plasma density, heating power, performance overall, e.g. setting new...
Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters December 2015. At end of 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were operation, allowing detailed studies many interesting plasma phenomena. For example, fast neutral gas manometers supported video cameras (including one fast-frame camera frame rates...
Abstract Classical particle drifts are known to have substantial impacts on fluxes of particles and heat through the edge plasmas in both tokamaks stellarators. Here we present results from first dedicated investigation drift effects W7-X stellarator. By comparing similar plasma discharges conducted with a forward- reverse-directed magnetic field, could be isolated observation up-down asymmetries flux profiles divertor targets. In low-density plasmas, radial locations strike lines (i.e....
An extensive examination of the plasma response to dominantly n = 2 non-axisymmetric magnetic perturbations (MPs) on DIII-D tokamak shows potential control 3D field interactions by varying poloidal spectrum radial field.The is calculated as a function applied structure and parameters, using linear magnetohydrodynamic code MARS-F (Liu et al 2000 Phys.Plasmas 7 3681).The ideal, single fluid decomposed into two main components: local pitch-resonant occurring at rational flux surfaces, global...
Key physics issues in the design of a high- quasi-axisymmetric stellarator configuration are discussed. The goal study is compact with aspect ratio comparable to that tokamaks and good transport stability properties. Quasi-axisymmetry has been used provide drift trajectories. Ballooning stabilization accomplished by strong axisymmetric shaping, yielding whose core second regime for ballooning modes. A combination externally generated shear non-axisymmetric corrugation plasma boundary...
A radio frequency field solver based on Maxwell's equations and a cold plasma dielectric tensor is employed to describe wave phenomena observed in cylindrical non-uniform helicon discharge. The experiment carried out recently built linear plasma-material interaction machine: magnetized [Blackwell et al., Plasma Sources Sci. Technol. (submitted)], which both density static magnetic are functions of axial position. strength increases by factor 15 from source target plate, the electron...
Parameter scans show the strong dependence of plasma response on poloidal structure applied field highlighting importance being able to control this parameter using non-axisymmetric coil sets. An extensive examination linear single fluid n = 3 magnetic perturbations in L-mode DIII-D lower null plasmas is presented. The effects resistivity, toroidal rotation and are calculated MHD code, MARS-F (Liu et al 2000 Phys. Plasmas 7 3681). Measures which separate into a pitch-resonant resonant...
An analytical model describing the physics of driven floating probes has been developed to RF compensation double langmuir probe (DLP) technique. The is based on theory self-bias effect as described in Braithwaite's work [1], which we extend include time-resolved behaviour. main contribution this allow quantitative determination intrinsic a DLP given discharge. Using these ideas, discuss design compensated DLPs. Experimental validation for ideas presented and effects rectification...
Water in seeds plays an important role not only physiological but also chemical processes. In addition to the requirements of water for germination, legumes used human consumption require hydration prepare them cooking. The site entry, however, and its movement during imbibition particularly soybean is still clear. One best most precise methods tracing plant tissue nuclear magnetic resonance (NMR) imaging. our study, we applied NMR imaging reveal distribution first 24 h hydration. It has...
This study is devoted to simulating the orbits of ions in supersonic beam observed experimentally laboratory development helicon double-layer thruster. Given cylindrical symmetry problem, particle are generated coordinates (r, Φ, z), thereby enabling analysis magnetic detachment (in which particles free themselves from field source) be confined curvature trajectories on z) plane. Because trajectory a magnetized space helical, can established if r(z) plane asymptotically approaches zero. The...
Antenna radiation patterns in the vicinity of a helicon antenna are investigated hydrogen plasmas produced MAGPIE linear plasma device. Using uniform cold-plasma full-wave code, we model wave physics and find good agreement with experimental measurements. We show for first time which elements device couple most strongly to discuss physical mechanism that determines this effect. Helicon wavefields near field best described terms group velocity ray direction, while far from antenna, behave...
In this paper, we investigate the propagation and damping of helicon waves along length (50 cm) a helicon-produced 20 kW hydrogen plasma ( 1–2 1019 m−3, 1–6 eV, H2 8 mTorr) operated in magnetic mirror configuration (antenna region: 50–200 G 800 G). Experimental results show presence traveling (4–8 10–15 propagating away from antenna region which become collisionally absorbed within 40–50 cm. We describe use WKB method to calculate wave provide an expression assess its validity based on...
The first experimental observation of the sudden transition to improved particle confinement mode in H-1 heliac is reported and shows a clear dependence on magnetic configuration. In low-temperature plasma followed by twofold increase electron density observed when field exceeds critical value ${B}_{\mathrm{cr}}$. At $B\ensuremath{\approx}{B}_{\mathrm{cr}}$ occurs spontaneously (within 1 ms). This ${B}_{\mathrm{cr}}$ strongly decreases with increasing rotational transform. improvement...
The design and evaluation of the Langmuir probe system used in first divertor operation phase Wendelstein 7-X is described. probes are integrated into target plates have individually facetted surfaces to keep angle incidence magnetic field within an appropriate range for different configurations. Multiple models derivation plasma parameters from current-voltage characteristics introduced. These analyzed with regard their assumptions limitations, generalized, adapted our use case. A detailed...