Canadian Economics Association

In system monitoring, automatic fault diagnosis seeks to infer the systems' state based on sensor readings, e.g., through machine learning models. In this context, it is of key importance that, based on historical data, these systems are able to generalize to incoming data. In parallel, many factors may induce changes in the data probability distribution, hindering the possibility of such models to generalize. In this sense, domain adaptation is an important framework for adapting models to different probability distributions. In this paper, we propose a new benchmark, based on the Tennessee Eastman Process of Downs and Vogel (1993), for benchmarking domain adaptation methods in the context of chemical processes. Besides describing the process, and its relevance for domain adaptation, we describe a series of data processing steps for reproducing our benchmark. We then test 11 domain adaptation strategies on this novel benchmark, showing that optimal transport-based techniques outperform other strategies.

The ITER Plasma Control System (PCS) controls all aspects of the ITER plant necessary to achieve the pulse scenario. This includes control over the magnets, fueling and auxiliary heating systems, but also many functions that monitor plasma operation limits and instabilities. This paper will describe how the ITER PCS is designed and report on the design status, highlighting some of the critical functions and design issues. The main functions such as magnetic, fueling and heating control and initial disruption avoidance are well underway, being detailed in the system engineering database (PCSDB) and being implemented in the PCS simulation platform (PCSSP) in Matlab/Simulink which jointly provide the PCS design description. The PCSSP is also key in permitting design assessment by simulating and testing the multitude of functions which comprise the PCS. We illustrate the overall PCS architecture with an example use-case: the complex, multi-task control scenario required to manage plasma operation with the Electron Cyclotron Heating (ECH) system. This has taken on even greater importance given the recent ITER organization re-baseline proposal which requests a very significant increase in the installed ECH power, doubling from 20 MW to 40 MW for the first operation phase, Start of Research Operations, and increasing further up to 67 MW for the deuterium-tritium campaigns. The PCS design in this case requires a clear breakdown into manageable sub-functions which focus on parameter monitoring, actual control, and the complex interface between the ITER PCS and the ECH system itself. Control functions include not just the control of the ECH power, but also related tasks, such as the control of [Neoclassical] Tearing Modes. The implementation requires the design of actuator management functions which efficiently manage the potentially conflicting actuation requests from PCS functions to the ECH system, as well as the exception handling functions that provide appropriate reactions to deal with off-normal events during plasma pulses.

Scientific and technical advancements have been made that improve fusion's prospects to provide a new energy source, showing enhanced plasma confinement conditions with plasma temperatures reaching or exceeding 100 million degrees. Overshadowing this progress is the challenge involved in developing an economically viable fusion power plant design. Many proposed next-step DEMO and pilot plant designs are extensions of existing physics-focused experimental devices defined to understand and control plasma operations to achieve and sustain a fusion reaction. Transitioning scientific and technical advancements into a functional power plant requires a dedicated focus on architectural designs that integrate diverse technologies, while optimizing physics conditions, with a focus on economic viability. This holistic approach is essential in turning the promise of fusion energy into a reality. The Spherical Tokamak Advanced Reactor (STAR) is a fusion power plant conceptual design with the architectural focus that strives to balance physics, engineering, and cost considerations. It has been set up to introduce relevant physics, engineering and concept features that an intermediate pilot plant might follow, with the goal of meeting system performances and economic requirements that lead to a commercially competitive fusion power plant.

We propose a novel phase-field (PF) model to enhance the description of grain boundaries (GBs) and its effect on the solute segregation behaviour under irradiation. Conventional PF models typically treat GBs as perfect sinks for point defects (PDs) such as vacancies and interstitials, often assuming the system's chemical potentials as homogeneous. Our approach employs a density function to represent the reduction in atomic density within GBs. Furthermore, we introduce a mixing term to account for ballistic damage, simulating the effects of PD generated by displacement cascades. This study demonstrates how our model featuring the density function correctly predicts equilibrium segregation and its impact on radiation-induced segregation (RIS) in Fe Cr alloys, a material widely used in the nuclear industry. Our methodology successfully reproduces the well-known " W-shape" segregation profiles, and provides insights into spinodal decomposition and ballistic mixing effects on GB segregation. This advanced PF model offers a better understanding of GBs behaviour under irradiation, potentially contributing to improved material design for nuclear applications.

An extensive documentation of ICRF-enhanced plasma potentials has been conducted over two experimental campaigns on the WEST tokamak using reciprocating emissive probes magnetically connected to two ICRF antennas. The collected data spans a wide range of antenna electrical settings (coupled power, toroidal phasing, left–right power balance) and plasma parameters (density at the antenna limiter above and below the lower hybrid resonance, plasma current, minority fraction). By scanning the edge safety factor across multiple probe plunges, the magnetic connection between the probe and the antenna varied, enabling the construction of a 2D map of the plasma and floating potentials around an active ICRF antenna. This dataset will be used to validate RF simulation tools equipped with the sheath boundary condition and used to predict RF rectified potentials and ICRF-induced impurity sputtering in future machines. This paper presents the diagnostic and some initial measurements, while the rest will be reported elsewhere.