A5033775111- Magnetic confinement fusion research
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Semiconductor materials and devices
- Solar and Space Plasma Dynamics
- Atomic and Subatomic Physics Research
- Gyrotron and Vacuum Electronics Research
- Muon and positron interactions and applications
- Patient-Provider Communication in Healthcare
- Child and Adolescent Psychosocial and Emotional Development
- Electron and X-Ray Spectroscopy Techniques
- Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes
- Nuclear Materials and Properties
- Neuroendocrine regulation and behavior
- Innovations in Medical Education
- X-ray Spectroscopy and Fluorescence Analysis
- Thin-Film Transistor Technologies
- Superconducting and THz Device Technology
- Medication Adherence and Compliance
Princeton Plasma Physics Laboratory
2015-2024
Princeton University
2011-2024
Westchester Medical Center
2023
New York Medical College
2023
Tel Aviv University
2021
University of Colorado Hospital
2020
University of Colorado Denver
2006-2020
Denver Health Medical Center
2006-2020
University of California, Los Angeles
2018
American Institute of Aeronautics and Astronautics
2018
Abstract Lithium wall coatings have been shown to reduce recycling, suppress edge-localized modes (ELMs), and improve energy confinement in the National Spherical Torus Experiment (NSTX). Here we document effect of gradually increasing lithium on discharge characteristics, with reference ELMy discharges obtained boronized, i.e. non-lithiated conditions. We observed a continuous but not quite monotonic reduction recycling improvement confinement, gradual alteration edge plasma profiles,...
Lithium wall coatings have been shown to reduce recycling, improve energy confinement, and suppress edge localized modes in the National Spherical Torus Experiment. Here, we show that these effects depend continuously on amount of predischarge lithium evaporation. We observed a nearly monotonic reduction decrease electron transport, modification profiles stability with increasing lithium. These correlations challenge basic expectations, given even smallest exceeded needed for nominal...
We report the first observation of global recycling coefficient R near 0.5 in Lithium Tokamak eXperiment-β (LTX-β), significantly below minimum previously reported other devices. In a series experiments with varied Li wall conditioning, estimates have been made using Lyman-α array and DEGAS2 modeling. A progressive reduction emission increased lithium an increase edge electron temperature are observed. It is also observed that increasing coating thickness, effective particle confinement time...
The need for physicians to have patient-centered communication skills is reflected in the educational objectives of numerous medical schools' curricula and competencies required by groups such as Accreditation Council Graduate Medical Education. An innovative method teaching communications has been developed at University Colorado School Medicine part its three-year, longitudinal course focusing on basic clinical all physicians. emphasizes techniques open-ended inquiry, empathy, engagement...
Joint experiment/theory/modelling research has led to increased confidence in predictions of the pedestal height ITER. This work was performed as part a US Department Energy Research Target FY11 identify physics processes that control H-mode structure. The study included experiments on C-Mod, DIII-D and NSTX well interpretation experimental data with theory-based modelling codes. provides ability models for peeling–ballooning stability, bootstrap current, width scaling make correct...
It has been predicted for over a decade that low-recycling plasma-facing components in fusion devices would allow high edge temperatures and flat or nearly temperature profiles. In recent experiments with lithium wall coatings the Lithium Tokamak Experiment (LTX), hot ($>200\text{ }\text{ }\mathrm{eV}$) electron profiles have measured following termination of external fueling. Reduced recycling was demonstrated by retention $\ensuremath{\sim}60%$ injected hydrogen walls discharge. Electron...
Research on the National Spherical Torus Experiment, NSTX, targets physics understanding needed for extrapolation to a steady-state ST Fusion Nuclear Science Facility, pilot plant, or DEMO. The unique operational space is leveraged test theories next-step tokamak operation, including ITER. Present research also examines implications coming device upgrade, NSTX-U. An energy confinement time, τE, scaling unified varied wall conditions exhibits strong improvement of BTτE with decreased electron...
Recently in the National Spherical Torus Experiment (NSTX), increasing lithium wall coatings suppressed edge localized modes (ELMs), gradually but not quite monotonically. This work details profile and stability analysis as ELMs disappeared throughout scan. While quantity of deposited between discharges did uniquely determine presence ELMs, demonstrated that was correlated with wider density pressure pedestals peak gradients farther from separatrix. Moreover, ELMy ELM-free were cleanly...
The first-ever successful operation of a tokamak with large area (40% the total plasma surface area) liquid lithium wall has been achieved in Lithium Tokamak eXperiment (LTX). These results were obtained new, electron beam-based evaporation system, which can deposit coating on limiting LTX five-minute period. Preliminary analyses diamagnetic and other data for discharges operated indicate that confinement times increased by 10× compared to helium-dispersed solid coatings. Ohmic energy fresh...
High edge electron temperatures (200 eV or greater) have been measured at the wall-limited plasma boundary in Lithium Tokamak Experiment (LTX). Flat temperature profiles are a long-predicted consequence of low recycling conditions. Plasma density outer scrape-off layer is very low, 2–3 × 1017 m−3, consistent with metallic lithium boundary. Despite high temperature, core impurity content low. Zeff estimated to be ∼1.2, modest contribution (<0.1) from lithium. Experiments transient. Gas...
A comparison of three sets Lithium Tokamak Experiment-β (LTX-β) discharges is presented, each with progressively more lithium evaporatively deposited on the stainless steel plasma facing components (PFCs). Multiple observations independently indicate a reduction in recycling increasing deposition - current, discharge duration, density pumpout, and edge electron temperatures increase while neutral influx decrease. These measurements make use several new operational diagnostics upgrades that...
Progress in characterizing the edge stability and properties of microinstabilities responsible for enhanced transport pedestal region is reported. The characterized high performance discharges on National Spherical Torus Experiment. These plasmas are found to be ideal kink-peeling infinite-n ballooning unstable prior onset edge-localized modes (ELM). spatial structure turbulence present during an ELM cycle indicates poloidal scales propagating ion diamagnetic drift direction at top, radial ....
The National Spherical Torus Experiment (NSTX) is currently being upgraded to operate at twice the toroidal field and plasma current (up 1 T 2 MA), with a second, more tangentially aimed neutral beam (NB) for rotation control, allowing pulse lengths up 5 s. Recent NSTX physics analyses have addressed topics that will allow NSTX-Upgrade achieve research goals critical Fusion Nuclear Science Facility. These include producing stable, 100% non-inductive operation in high-performance plasmas,...
Abstract Recent experiments in the lithium tokamak experiment- β (LTX- ) have extended duration, performance, operating conditions, and diagnosis of flat-temperature profile, low-recycling regime first observed LTX. As expected, Li retains hydrogen suppresses edge neutral cooling, allowing increased electron temperature, roughly equal to core T e . Flat temperature profiles had been obtained transiently LTX, as plasma density decayed following cessation gas puffing. Careful control over...
The Lithium Tokamak eXperiment is a small, low aspect ratio tokamak [Majeski et al., Nucl. Fusion 49, 055014 (2009)], which fitted with stainless steel-clad copper liner, conformal to the last closed flux surface. liner can be heated 350 °C. Several gas fueling systems, including supersonic injection and molecular cluster injection, have been studied produce efficiencies up 35%. Discharges are strongly affected by wall conditioning. without lithium coatings limited plasma currents of order...
Objective Our objective was to determine the impact of Health Literacy Universal Precautions Toolkit, adapted for rheumatology, on medication adherence, patient satisfaction, and feasibility in all patients; its effect clinical disease activity index ( CDAI ) studied a rheumatoid arthritis RA subpopulation. Methods Data collected during 6‐month prospective quality assurance intervention compared with data from prior period. Interventions included 1) encouraging questions, 2) teach‐back...
Lithium coatings in the Tokamak eXperiment (LTX) led to flat temperature profiles. The profiles were observed along with a hot, low density edge, implying broad, collisionless scrape-off layer (SOL). Additionally, vacuo X-ray photoelectron spectroscopy (XPS) measurements established that lithium evaporatively deposited onto high-Z plasma facing components (PFCs) became oxidized while retaining ability achieve good performance long after was applied PFCs. Longstanding theory predicted...
Abstract We present observations, numerical simulations, and analysis from experiments in the Lithium Tokamak Experiment-Beta (LTX- β ) which electron temperature profile ( T e r )) shifts flat to peaked a tearing mode is also destabilized when average density n ave exceeds ∼10 19 m −3 . Flat obtained routinely LTX- , with lithium coated, low-recycling first wall, once external fueling stopped decays [Boyle et al 2023 Nucl. Fusion 63 056020]. In experiment, profiles can be sustained while...