The MIT Plasma Science and Fusion Center and its collaborators are proposing a high-magnetic field, high-performance Advanced Divertor and RF tokamak eXperiment (ADX) – a tokamak specifically designed to address critical gaps in the world research program on the pathway to fusion energy. This device is conceived as a compact, high-magnetic field, high-power density tokamak that implements cutting-edge innovations in the areas of plasma power exhaust, plasma-wall interactions, and radio-frequency current drive and heating.
The purpose-built, collaborative, affordable experimental platform will enable innovative divertor concepts to be explored in regimes of interest for future reactors. The flexible divertor conditions accessed in ADX would surpass that of any other tokamak presently existing or being planned in the world. The device will be able to expose fusion-relevant plasma-facing materials to heat fluxes similar to those experienced on the surface of the sun while testing various means to effectively handle the heat without degrading the plasma performance.
The experimental platform will also provide the means to test potential game-changing concepts for radio frequency current drive and heating at reactor-level magnetic field strengths and plasma densities in a toroidal plasma. As an example: the experiment has the unprecedented ability to deploy launch structures both on the low-magnetic-field side and the high-magnetic-field side where performance is theorized to be much better.
This triple combination – advanced divertors, advanced RF actuators, and reactor-prototypical core plasma conditions – will enable ADX to explore enhanced core confinement physics using only the types of external drive systems that are considered viable for a fusion power plant.
The experiment leverages the extensive experience with compact tokamaks, high magnetic fields, divertor physics, plasma-material interactions, RF heating and current drive at the PSFC and its collaborators. ADX will be able to provide timely answers to existential questions that face the world magnetic-confinement fusion effort. Such an integrated demonstration of high-performance core-divertor operation with steady state sustainment would pave the way toward an attractive pilot plant, such as envisioned in the ARC concept.