Publications
Showing 31 results for Author: Elijah H. Martin
Aug, 2025
Journal
WEST full tungsten operation with an ITER grade divertor
The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation in a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with a focus on testing the ITER actively cooled W divertor in tokamak conditions. Following the successful completion of phase 1 (2016-2021), phase 2 started in December 2022 with…
Dec, 2024
Journal
Implementation of a Doppler-Free Saturation Spectroscopy (DFSS) Diagnostic for Helicon Wave Electric Field Vector Measurement in Edge Plasma in DIII-D
A laser-based technique known as Doppler-free saturation spectroscopy (DFSS) has been designed, fabricated, and installed on the DIII-D National Fusion Facility to measure the helicon wave electric field vector in the edge plasma. These experimental measurements quantify phenomena resulting in decreased current drive efficiency due to wave/edge plasma interactions. This im…
Oct, 2024
Journal
First high-power helicon results from DIII-D
More than 0.6 MW of rf power at 476 MHz has been coupled to DIII-D plasmas by launching helicon (whistler) waves with a traveling-wave antenna (comb-line) in the fast-wave polarization (Van Compernolle et al 2021 Nucl. Fusion 61 116034) which resulted in the observation of electron heating of the core plasma with single-pass absorption based on ray-tracing in L-mode discha…
Dec, 2023
Journal
DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy
DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance…
Dec, 2023
ORNL Report
Summary of RF Technology Program Activities, October 2013 — September 2017
The goals of the National RF Research and Development Program (NRRDP) are to advance the basic understanding of high power radio frequency (RF) in a plasma environment, and to maintain the high-power transmitters and cooling water systems required to support the ITER Ion Cylcotron Range of Frequencies (ICRF) transmission line high power component testing and operation of t…
Dec, 2023
Journal
Developing high performance RF heating scenarios on the WEST tokamak
High power experiments, up to 9.2 MW with LHCD and ICRH, have been carried out in the full tungsten tokamak WEST. Quasi non inductive discharges have been achieved allowing to extend the plasma duration to 53 s with stationary conditions in particular with respect to tungsten contamination. Transitions to H mode are observed, and H-modes lasting up to 4 s have been obtaine…
Dec, 2023
Journal
WEST actively cooled load resilient ion cyclotron resonance heating system results
Three identical new WEST ion cyclotron resonance heating (ICRH) antennas have been designed, assembled then commissioned on plasma from 2013 to 2019. The WEST ICRH system is both load-resilient and compatible with long-pulse operations. The three antennas have been successfully operated together on plasma in 2019 and 2020, with up to 5.8 MW of coupled power. The load resil…
Dec, 2023
Conference Paper
WEST Actively Cooled Load Resilient Ion Cyclotron Resonance Heating Results