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Showing 1 to 19 of 19 for “"ion temperatures"”.
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Ion Temperatures in Earth's Inner Magnetosphere: Ring Current Dynamics, Transient Effects, and Data-Model Comparisons
… be understood as a balance between multiple regions which all exhibit unique plasma properties. The feedback processes between each region depend on geomagnetic activity levels and the preceding states of the solar wind and the respective magnetospheric regions. Of particular interest is …
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Slow wave ion heating and parametric instabilities in the HELIX helicon source
… the mechanism responsible for intrinsic ion heating in helicon sources. Two possible mechanisms have been identified: ion Landau damping of the slow wave and parametrically driven instabilities. Consistent with ion Landau damping of the slow wave, the perpendicular ion temperatures 35 cm …
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Resonant ion heating in a helicon plasma
A resonant ion heating system has been developed for heating ions and controlling the ion temperature anisotropy in a helicon plasma source. The system uses two rectangular coils placed on either side of the cylindrical pyrex vacuum chamber to create a time dependent magnetic field transverse to …
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Direct Ion-Temperature Measurements Using High-Resolution Inelastic X-ray Scattering
… have extremely short lifetimes. Historically, ion temperature has been inferred from structural measurements that serve only as proxies. This approach becomes especially problematic when studying the evolution of highly nonequilibrium states generated by short-pulse laser-matter interactions. …
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Construction And Demonstration Of A Tandem Mass Spectrometer Based Instrument For Cold Ion Spectroscopy
<p>A new instrument incorporating ion trap based tandem mass spectrometry and cold ion UV and UV-IR double resonance spectroscopy has been developed at Purdue University for the study of gas phase, biologically relevant ions. The instrument incorporates multiple quadrupole linear ion trap mass …
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A TECHNIQUE FOR MEASURING THE TIME RESPONSE AND THROUGH-PUT DELAY OF NEUTRON TIME-OF-FLIGHT (nTOF) SCINTILLATION DETECTORS USING COSMIC RADIATION IN A COINCIDENCE SYSTEM
… are used to measure neutron signals from fusion experiments. These nTOF signals yield a temporal pulse width that is used to determine ion temperatures after the de-convolution of the experimentally determined detector time response and shifted to account for the detector through-put delay. …
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Optimization of a helicon plasma source for maximum density with minimal ion heating
… of electron density and perpendicular ion temperatures in an argon helicon plasma are presented for five different antennas: A Nagoya type III antenna, a double-saddle antenna, a 19 cm long m = +1 helical antenna, a 30 cm long m = +1 helical antenna and a 19 cm m = +1 helical antenna …
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Tokamak burn phase energy optimization with volumetric and wall interaction effects
… during the burn phase will depend upon the ion temperatures and densities. The ion source rates and the plasma current can be varied to control the ion densities. The impurity concentration of the plasma can be controlled by incorporating a charged particle divertor. A dynamic model of the …
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Incoherent scatter modeling of Jicamarca radar spectra
… density irregularities of the topside equatorial ionosphere probed by the Jicamarca Incoherent Scatter Radar (ISR) located near Lima, Peru. The topside equatorial ionosphere is a multi-ion plasma and the spectrum of its electron density irregularities can be modeled by extending the single-ion …
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Full-profile inversion of ionospheric radar data from Arecibo observatory
… radar (ISR) technique is used to probe the ionosphere and measure the key state parameters of the ionosphere in thermodynamic equilibrium, including its electron density, ion densities and compositions, electron and ion temperatures, and the associated drift velocities of ionospheric …
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Characterization of ion properties in a linear pulsed plasma-material interaction test stand
In the edge and divertor regions of the magnetically confined plasma, tokamaks experience off-normal events in which high intensities of heat flux incident on wall component surfaces result in intolerable levels of damage. Proposed solid divertors will not be able to withstand these fluxes, …
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Physics of RF heating systems on proto-MPEX
Realizing controlled fusion as a commercial energy source is faced with many challenges. One of the main challenges being the development of Plasma Facing Components (PFC) that can survive the extreme environment encountered in a fusion reactor. To expedite the testing and development of PFCs Oak …
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Exploring evolution of multi-ion effects and electron temperature in ICF implosions at Omega and the NIF
In inertial confinement fusion (ICF) implosions, one of the most important parameters for quantifying performance is temperature. In this thesis, effects related to temperature evolution of both the ions and electrons within the central plasma are explored in detail. From measurements of multiple …
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The effects of organic gases on atomic spectrometric signals in the ICP
… principal use of the ICP has been as an excitation cell for atomic emission spectrometry (AES). More recently, it has been used as an atomization cell for atomic fluorescence spectrometry (AFS). Since the ICP is an energetic source, the vaporization process is efficient. This high temperature …
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Thermonuclear Driven Fast Magnetosonic Wave Heating in Tokamak Plasmas
… is investigated in tokamak plasmas for propagation transverse to the external magnetic field at frequencies of several times the alpha particle gyro rate: (omega)(TURNEQ)L(OMEGA)(, ) =k(,(PERP))v(,A), L(TURN)4 to 8, k(,(PARLL))<<k(,(PERP)). The 2-D differential quasi-linear diffusion equation is …
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Studies of non-hydrodynamic processes in ICF implosions on OMEGA and the National Ignition Facility
Ion kinetic effects are expected to modify plasma dynamics when ion mean-free-paths and collision times become comparable to the scale sizes of the plasma. Such conditions arise during the shock convergence phase of inertial confinement fusion (ICF) implosions, when they may modify the compression …
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Ion and electron temperatures in the topside ionosphere
Experimental and theoretical ion and electron temperatures in the topside ionosphere are investigated. Experimental results come from an analysis of incoherent-scatter data taken at Arecibo, Puerto Rico. Consideration of the energy balance equations gives the theoretical ion and electron …
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Long-pulse incoherent scatter probing of the F-region ionosphere at Arecibo
… scatter radar (ISR) experiments probing the F-region ionosphere at Arecibo utilize three types of transmission envelopes having different range-mixing and error statistical models on their corresponding backscattered pulse returns. The binary-coded envelope with wide bandwidth (0.44 ms duration …
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Near-optimal inversion of incoherent scatter radar measurements: coding schemes, processing techniques, and experiments
Accurate and efficient estimation of the key ionospheric state parameters such as electron density, ion composition, and electron and ion temperatures is required to understand fundamental issues of terrestrial plasma physics such as redistribution of energy and momentum, and coupling within …