DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: WEST full tungsten operation with an ITER grade divertor

Journal Article · · Nuclear Fusion
 [1]; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ORCiD logo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
  1. CEA, IRFM, Saint Paul Lez Durance (France); et al.

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 the lower divertor made entirely of actively cooled ITER-grade tungsten mono-blocks. A boronization prior the first plasma attempt allowed for a smooth startup with the new divertor. Despite the reduced operating window due to tungsten, rapid progress has been made in long pulse operation, resulting in discharges with a pulse length of 100 s and an injected energy of around 300 MJ per discharge. Plasma startup studies were carried out with equatorial boron nitride limiters to compare them with tungsten limiters, while Ion Cyclotron Resonance Heating assisted startup was attempted. High fluence operation in attached regime, which was the main thrust of the first campaigns, already showed the progressive build up of deposits and appearance of dust, impacting the plasma operation as the plasma fluence increased. In total, the cumulated injected energy during the first campaigns reached 43 GJ and the cumulated plasma time exceeded 5 h. Demonstration of controlled X-Point Radiator regime is also reported, opening a promising route for investigating plasma exhaust and plasma-wall interaction issues in more detached regime. This paper summarises the lessons learned from the manufacturing and the first operation of the ITER-grade divertor, describing the progress achieved in optimising operation in a full W environment with a focus on long pulse operation and plasma wall interaction.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE; USDOE Office of Science (SC)
Grant/Contract Number:
AC02-09CH11466; AC05-00OR22725
OSTI ID:
2496688
Journal Information:
Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 11 Vol. 64; ISSN 0029-5515
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English

References (44)

Flush-mounted Langmuir probes in the WEST tokamak divertor journal February 2021
Design and integration of femtosecond Fiber Bragg gratings temperature probes inside actively cooled ITER-like plasma-facing components journal May 2021
First temperature database achieved with Fiber Bragg Grating sensors in uncooled plasma facing components of the WEST lower divertor journal September 2021
A new 3MW ECRH system at 105 GHz for WEST journal January 2023
Surface heat flux estimation with embedded thermocouples and Fiber Bragg Grating sensor in ITER-like plasma facing components journal May 2023
Manufacturing, testing and installation of the full tungsten actively cooled ITER-like divertor in the WEST tokamak journal August 2023
T-REX: Numerical tool for tungsten damage assessment for DEMO journal October 2022
Reception tests of the WEST PFUs using ultrasonic testing and infrared thermography journal September 2022
First 3D modelling of tungsten erosion and migration in WEST discharges adopting a toroidally non-symmetric wall geometry journal March 2023
Overview of plasma-tungsten surfaces interactions on the divertor test sector in WEST during the C3 and C4 campaigns journal March 2023
Testing of ITER-grade plasma facing units in the WEST tokamak: Progress in understanding heat loading and damage mechanisms journal December 2023
Development of visible spectroscopy diagnostics for W sources assessment in WEST journal August 2016
Fast modeling of turbulent transport in fusion plasmas using neural networks journal February 2020
Impact of divertor neutral pressure on confinement degradation of advanced tokamak scenarios at ASDEX Upgrade journal February 2024
Investigation of steady-state tokamak issues by long pulse experiments on Tore Supra journal September 2009
Variational approach to radiofrequency waves in magnetic fusion devices journal July 2009
Heating and current drive by ion cyclotron waves in the activated phase of ITER journal December 2012
Healing plasma current ramp-up by nitrogen seeding in the full tungsten environment of WEST journal February 2022
Characterizing W sources in the all-W wall, all-RF WEST tokamak environment * , ** journal September 2022
Extreme UV spectroscopy measurements and analysis for tungsten density studies in the WEST tokamak journal September 2022
Tungsten accumulation during ion cyclotron resonance heating operation on WEST journal November 2023
Stability analysis of WEST L-mode discharges with improved confinement from boron powder injection journal March 2024
Erosion and redeposition patterns on entire erosion marker tiles after exposure in the first operation phase of WEST journal September 2021
Impact of divertor geometry on H-mode confinement in the JET metallic wall journal June 2017
Metis: a fast integrated tokamak modelling tool for scenario design journal August 2018
Erosion, screening, and migration of tungsten in the JET divertor journal August 2019
Characterisation of highly radiating neon seeded plasmas in JET-ILW journal October 2019
Pedestal structure, stability and scalings in JET-ILW: the EUROfusion JET-ILW pedestal database journal November 2020
X-point radiation, its control and an ELM suppressed radiating regime at the ASDEX Upgrade tokamak journal December 2020
The updated ITPA global H-mode confinement database: description and analysis journal January 2021
Divertor power loads and scrape off layer width in the large aspect ratio full tungsten tokamak WEST journal August 2021
Operating a full tungsten actively cooled tokamak: overview of WEST first phase of operation journal February 2022
Confinement in electron heated plasmas in Wendelstein 7-X and ASDEX Upgrade; the necessity to control turbulent transport journal December 2021
Overview of the emissivity measurements performed in WEST: in situ and post-mortem observations journal August 2022
Initial results from boron powder injection experiments in WEST lower single null L-mode plasmas journal June 2022
Core radiative collapse characterisation and integrated modelling in WEST plasmas journal September 2022
Developing high performance RF heating scenarios on the WEST tokamak journal November 2022
Separatrix parameters and core performances across the WEST L-mode database journal April 2023
Optimization of the operational domain for ICRH scenarios in WEST from statistical analysis journal June 2023
Maximizing the ion temperature in an electron heated plasma: from WEST towards larger devices journal January 2024
Calorimetry measurement for energy balance and energy distribution in WEST for L-mode plasmas journal February 2024
Surface temperature measurement from infrared synthetic diagnostic in preparation for ITER operations journal July 2024
Evolution of pre-damaged ITER grade plasma facing components under WEST plasma exposure: smoothing and tungsten sources journal August 2024
Calculation of the radiated power in WEST journal September 2021