A5091797872- Fusion materials and technologies
- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Nuclear Materials and Properties
- Ion-surface interactions and analysis
- Laser-Plasma Interactions and Diagnostics
- Mass Spectrometry Techniques and Applications
- Diamond and Carbon-based Materials Research
- Ionosphere and magnetosphere dynamics
- Metal and Thin Film Mechanics
- Particle accelerators and beam dynamics
- Plasma Applications and Diagnostics
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Cold Fusion and Nuclear Reactions
- Dust and Plasma Wave Phenomena
University of California, San Diego
2021-2024
Jacobs (United States)
2023
National Cheng Kung University
2019
The helicon-plasma based-linear plasma-materials-interaction device, Pisces-RF is introduced. Steady-state plasma parameters in the target region are electron density up to ∼1019 m−3, temperature ∼10 eV, and ion flux ∼1023 m−2s−1 D2 He, with an associated maximum peak heat of ∼1 MWm−2 a few when accelerating ions electrical bias. Attached detached regimes both gaseous species can be achieved, as characterized by high low Te (<1eV) plasmas fractions singly ionized atomic ions. downstream...
Abstract Radio-frequency (RF) driven helicon plasma sources can produce relatively high-density plasmas ( n > 10 19 m −3 ) at moderate powers (<2 kW) in argon. However, to similar for fusion relevant gases such as hydrogen (H), deuterium (D) and helium (He), much higher RF are needed. For very high powers, thermal issues of the RF-transparent dielectric window, used source design, limit operation timescales. To mitigate this constraint, we have designed, built tested a novel assembly...
It has been demonstrated that the electron density, ne, and temperature, Te, are successfully evaluated from He I line intensity ratios coupled with machine learning (ML). In this paper, ML-aided ratio technique is applied to deuterium (D) plasmas 0.031 &lt; ne (1018 m−3) 0.67 2.3 Te (eV) 5.1 in PISCES-A linear plasma device. Two ratios, Dα/Dγ Dα/Dβ, used develop a predictive model for separately. Reasonable agreement of both those single Langmuir probe measurements obtained at &gt;...
Abstract Properties of deuterium (D) supersaturated surface layers (DSSLs) formed in tungsten (W), such as thickness, internal microstructures, and D retention, are experimentally investigated a function the incident ion energy, E i . W samples were exposed to plasmas PISCES-A linear plasma device range ∼ 45–175 eV, while other exposure parameters fixed: sample temperature, T s , ∼423 K, flux, Γ ∼1.2 × 10 21 m −2 −1 fluence, Φ ∼3.0 24 High-resolution, cross-sectional, transmission electron...
The formation of microscopic cone-like structures on a Cr surface is observed under He plasma exposure at low incident ion energy ∼106 eV in the PISCES-A linear device. 2D emission profiles I line intensity, measured with hyperspectral imaging camera, are compared those modeled using GITR Monte Carlo impurity transport code coupled SDTrimSP binary collision code. With growth cones, experimental profile becomes axially elongated and intensity significantly drops, these observations...
Abstract We reply to the comment by Li et al (submitted Nucl. Fusion with this response) on our recent paper Nishijima (2023 63 126003). In response, we address existence of an incident ion energy, E i , threshold for deuterium (D) supersaturated surface layer (DSSL) formation a newly conducted D plasma exposure experiment at ∼ 20 eV. It is also further demonstrated, based new experiments where flux, fluence, and sample temperature are scanned, that non-kinetic (ballistic) processes play...
The influence of a fuzzy surface on the physical sputtering Mo in He plasmas has been studied with hyperspectral imaging (HSI) measurements and simulations that couple TRI3DYN code an impurity transport code. 2D profiles I line emission intensity from HSI images reveal yield, Y, is reduced to ∼40% smooth-surface value due presence fuzz layer, while angular distribution sputtered atoms might not change significantly. reproduce Y reduction successfully, but indicate causes increase small-angle...
Solitary drift waves (SDWs) in magnetized plasmas were discovered and then first investigated by experiment numerical simulation the Kyushu University group [i.e., H. Arakawa et al., Plasma Phys. Controlled Fusion 52, 105009 (2010)]. However, formation mechanisms of SDWs still await thorough examination. Our work experimentally identifies a clear transition from turbulent (DWs) to for varied radial gradients background density, which is agreement with preceding simulations [M. Sasaki Plasmas...
Radio-frequency (RF) driven helicon plasma sources can produce relatively high-density plasmas (n > 10^19 m-3) at moderate powers (< 2 kW) in argon. However, to similar for fusion relevant gases such as hydrogen, deuterium and helium, much higher RF are needed. For very high powers, thermal issues of the RF-transparent dielectric window, used source design, limit operation timescales. To mitigate this constraint, we have designed, built tested a novel liquid-cooled window which allows...