The Italian Divertor Test Tokamak (IDTT) facility is a new machine proposed to study advanced exhaust solutions in conditions approaching those planned for DEMO. The capabilities and access characteristics of such machine open the possibility to test and validate relevant non-magnetic control diagnostics, in reactor like regimes, in support of a DEMO design implementation. O-mode reflectometry, due to its compatibility with a full grade reactor implementation, was proposed as a source of real-time (RT) plasma position and shape measurements for control purposes, in replacement or complement of standard magnetic measurements. On DEMO, the foreseen placement of magnetic sensors behind the blanket modules, and the inherent delay introduced in corresponding measurements, means that a fast position and shape feedback controller must make use of multiple, poloidally distributed, non-magnetic measurements such as the ones provided by O-mode reflectometry. This new control technique must be tested, in all of its aspects, before it can be fully implemented in future fusion reactors. IDTT presents itself as one of the best candidates to implement and build a knowledge database of nonstandard reflectometry (away from the equatorial plane) that will be needed on DEMO and is currently unavailable. The main goal of this work is to assess the performance of a set of 3 plasma position reflectometers (PPR) at the Lower Field Side (LFS) on IDTT. This assessment was carried out using the two-dimensional (2D) full-wave finite-difference time-domain (FDTD) code, REFMULF, in two of the foreseen IDTT plasma scenarios: 5MA Single Null (SN) and Double Null (DN) configurations, at the Start Of Flat (SOF), T=36s, that is at the start of the flat top of the plasma current. These scenarios are the most common ones and constitute a consistent starting point for the assessment of the possibility of having one or more PPR systems at IDTT.
Assessment of Measurement Performance for a Low Field Side IDTT Plasma Position Reflectometry System
De Masi Gianluca;
2020
Abstract
The Italian Divertor Test Tokamak (IDTT) facility is a new machine proposed to study advanced exhaust solutions in conditions approaching those planned for DEMO. The capabilities and access characteristics of such machine open the possibility to test and validate relevant non-magnetic control diagnostics, in reactor like regimes, in support of a DEMO design implementation. O-mode reflectometry, due to its compatibility with a full grade reactor implementation, was proposed as a source of real-time (RT) plasma position and shape measurements for control purposes, in replacement or complement of standard magnetic measurements. On DEMO, the foreseen placement of magnetic sensors behind the blanket modules, and the inherent delay introduced in corresponding measurements, means that a fast position and shape feedback controller must make use of multiple, poloidally distributed, non-magnetic measurements such as the ones provided by O-mode reflectometry. This new control technique must be tested, in all of its aspects, before it can be fully implemented in future fusion reactors. IDTT presents itself as one of the best candidates to implement and build a knowledge database of nonstandard reflectometry (away from the equatorial plane) that will be needed on DEMO and is currently unavailable. The main goal of this work is to assess the performance of a set of 3 plasma position reflectometers (PPR) at the Lower Field Side (LFS) on IDTT. This assessment was carried out using the two-dimensional (2D) full-wave finite-difference time-domain (FDTD) code, REFMULF, in two of the foreseen IDTT plasma scenarios: 5MA Single Null (SN) and Double Null (DN) configurations, at the Start Of Flat (SOF), T=36s, that is at the start of the flat top of the plasma current. These scenarios are the most common ones and constitute a consistent starting point for the assessment of the possibility of having one or more PPR systems at IDTT.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
