ITER Physics Basis

ITER Physics Basis
Title	ITER Physics Basis
Discipline	Nuclear fusion, Plasma physics
Related	ITER, Tokamak, Magnetic confinement
Published	1999
Editors	Jonathan Feder, Marc Romanelli, John Wesson

ITER Physics Basis

The ITER Physics Basis is a comprehensive synthesis of theoretical analysis, empirical scaling, and experimental results assembled to guide design choices for the ITER tokamak and to predict performance for burning plasma scenarios. It consolidates knowledge from major facilities such as JET, TFTR, DIII‑D, and JT-60U, and from collaborations including the International Atomic Energy Agency, the European Fusion Development Agreement, and national laboratories like Oak Ridge National Laboratory and Culham Centre for Fusion Energy. The document underpins engineering decisions for plasma shaping, heating, stability, and materials selection while interfacing with projects such as DEMO, SPARC (tokamak), and international consortia.

Overview and Objectives

The primary objective of the ITER Physics Basis was to deliver validated plasma performance projections for steady-state and pulsed operation in a reactor-scale tokamak, informing key parameters like plasma current, beta, confinement time, and auxiliary power. It brings together contributions from experimental campaigns at ASDEX Upgrade, RFX, and COMPASS and from theoretical work at institutes including Max Planck Institute for Plasma Physics and Princeton Plasma Physics Laboratory. The compilation sets targets for operational regimes relevant to the Fusion Energy Sciences Advisory Committee recommendations and aligns with milestones from the ITER Organization and participating domestic agencies such as CEA (Commissariat à l'énergie atomique et aux énergies alternatives) and Japan Atomic Energy Agency. Emphasis lies on producing reliable scalings and physics limits that interact with engineering constraints from entities like General Atomics.

Plasma Confinement and Transport

Confinement scaling in the ITER Physics Basis synthesizes empirical scalings (e.g., the IPB98(y,2) scaling) with theoretical transport models developed by groups at MIT Plasma Science and Fusion Center, Columbia University, and University of California, San Diego. It correlates energy confinement time with machine size, plasma current, and heating power using experimental databases from JET, TEXTOR, and C-Mod. Turbulent transport descriptions draw on gyrokinetic simulation benchmarking performed at LLNL and Max Planck Institute for Plasma Physics, and on analytic theory from researchers at Culham Centre for Fusion Energy and Kyoto University. The Basis addresses pedestal physics informed by measurements at DIII‑D and ASDEX Upgrade and connects edge-localized mode (ELM) behavior to global confinement through integrated modeling by teams at Princeton University and Korea Institute of Fusion Energy.

Heating, Current Drive, and Diagnostics

The heating and current-drive chapter synthesizes experimental results for neutral beam injection systems like those developed by Oak Ridge National Laboratory and radio-frequency systems (ion cyclotron and electron cyclotron) demonstrated at JT-60U and EAST. It assesses coupling efficiency, deposition profiles, and current-drive fraction relevant to noninductive scenarios pursued by collaborators at ITER Organization and US ITER. Diagnostics strategies compile mature systems—Thomson scattering, reflectometry, and charge exchange recombination spectroscopy—used at JET, DIII‑D, and ASDEX Upgrade, and outline advanced techniques such as collective scattering, motional Stark effect, and neutron emission spectroscopy developed by groups at Lawrence Livermore National Laboratory and Rutherford Appleton Laboratory. These elements support feedback control schemes employed in experiments at NSTX-U and proposals for real-time control in SPARC (tokamak)-class devices.

Magnetohydrodynamics and Stability

Stability limits documented in the Basis cover ideal and resistive magnetohydrodynamic (MHD) instabilities, including kink, tearing, and resistive wall modes, drawing on analytic work from General Atomics and simulations from CEA and Princeton Plasma Physics Laboratory. The document integrates experimental observations of neoclassical tearing modes from DIII‑D and sawtooth behavior studied at JT-60SA and TFTR archives. It evaluates disruption mitigation strategies such as massive gas injection and shattered pellet injection developed by teams at Oak Ridge National Laboratory and Culham Centre for Fusion Energy, and considers stabilizing techniques like active feedback coils and plasma rotation control pioneered at ASDEX Upgrade and JT-60U.

Materials, Plasma–Wall Interactions, and Tritium Breeding

Material choices and plasma–wall interaction (PWI) physics in the Basis draw on experiments with tungsten and beryllium surfaces at ITER-like Wall experiments in JET and on erosion/deposition studies from PISCES and RFX. It addresses tritium retention and codeposition informed by work at Sandia National Laboratories and Japan Atomic Energy Agency facilities. The tritium breeding requirements are connected to breeding blanket concepts from teams at KIT (Karlsruhe Institute of Technology), ENEA, and CIEMAT, exploring lithium-based ceramics, liquid breeders, and structural materials developed by Oak Ridge National Laboratory and CEA. Neutronics and activation analyses referenced include work by ITER Organization collaborators and national laboratories such as Idaho National Laboratory.

Experimental Program and Performance Predictions

Performance predictions in the ITER Physics Basis combine empirical confinement scalings, stability limits, and heating/current-drive expectations to forecast fusion power, gain (Q), and operating windows. Scenarios span inductive, hybrid, and steady-state regimes benchmarked against results from JET, JT-60U, and DIII‑D, and they feed into integrated modelling suites developed by consortia including European Fusion Development Agreement partners and the US Burning Plasma Organization. The program outlines experimental priorities—such as integrated scenario development, ELM control, and noninductive operation—that have driven subsequent campaigns at ITER preparatory facilities and informed design updates incorporated by the ITER Organization and participating domestic agencies.

Category:ITER Category:Plasma physics Category:Nuclear fusion