This paper presents the first observations of coherent beam ion losses due to plasma waves in the DIII-D tokamak. The actual measurement is the flux of beam ions that hit a probe located at the outer wall. That diagnostic, the Fast Ion Loss Detector (FILD), was built as part of a collaboration with the ASDEX Upgrade tokamak. […]
Modeling the Response of a Fast Ion Loss Detector Using Orbit Tracing Techniques in a Neutral Beam Prompt Loss Study on the DIII-D Tokamak
This paper details a method for correlating measurements of beam ion losses with the injection of individual beams in the DIII-D tokamak. This turns out to be a great tool for making sense of the measurements. The probe measures ion impacts, and then we use particle orbit calculations to backtrack the ions to specific beams. […]
Thesis – Chapter 5: Comparison between Temperature Filament and Limiter-Edge Experiments
Thesis – Table of Contents Comparisons Between Turbulent Features of the Temperature Filament and Limiter-Edge Experiments About the Limiter-Edge Experiment The limiter-edge experiment focuses on properties and generation of intermittent, or bursty, turbulence structures. As with the temperature filament experiment of this thesis, the turbulence study is motivated by the relevance to transport. Intermittent turbulence […]
Thesis – Chapter 4: Exponential Frequency Spectrum and Lorentzian Pulses (Part 2)
Thesis – Table of Contents Exponential Frequency Spectrum and Lorentzian Pulses (cont.) 4.3 Lorentzian Pulses The normalized form of a temporal Lorentzian pulse, L(t) , is (Eq. 4.1), where the pulse is centered at time to and has width τ. In 4.1, the time width is equal to one-half of the full width at half […]
Thesis – Chapter 4: Exponential Frequency Spectrum and Lorentzian Pulses (Part 1)
Thesis – Table of Contents Exponential Frequency Spectrum and Lorentzian Pulses During the early evolution of the temperature filament a pressure gradient forms in response to input heating from an electron beam. At these early times, the transport of thermal energy is observed to be in agreement with classical theory. This Chapter is concerned with […]
Thesis – Chapter 3: Identification of a Spontaneous Thermal Wave
Thesis – Table of Contents Identification of a Spontaneous Thermal Wave In recent years the venerable topic of thermal (diffusion) waves [Ångström, 1862] has received increased attention [Mandelis, 2000], primarily in the context of modern methodologies for diagnosing the properties of condensed and gaseous matter. Advances in experimental techniques and in the understanding of the […]