Characterisation of a dimensional metrology diagnostic for the lithium target of the IFMIF-DONES facility
The advancement of nuclear fusion technology has led to a growing need for accurate diagnostic instruments to ensure the safety and effectiveness of fusion reactors. This thesis focuses on the creation and evaluation of a dimensional measurement diagnostic system based on Light Detection and Ranging...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/424048 |
| Acceso en línea: | https://hdl.handle.net/2117/424048 |
| Access Level: | acceso embargado |
| Palabra clave: | Nuclear fusion Optical radar Fusion reactors LIDAR AM FM APD percision accuracy Lockin amplifier Fusió nuclear Radar òptic Reactors de fusió Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica |
| Sumario: | The advancement of nuclear fusion technology has led to a growing need for accurate diagnostic instruments to ensure the safety and effectiveness of fusion reactors. This thesis focuses on the creation and evaluation of a dimensional measurement diagnostic system based on Light Detection and Ranging (LIDAR) specifically designed for the IFMIF-DONES (International Fusion Materials Irradiation Facility - Demo Oriented Neutron Source) facility. The IFMIF-DONES project, within which this system is developed, aims to test materials for nuclear fusion reactors. The DONES-FLUX (Demo Oriented Neutron Source Flux) project is a publicly funded project that allows the development of specific subsystems of the IFMIF-DONES facility which are concerned with fluxes within the facility, be they electrical neutrons of lithium focus. In this project, high-energy neutrons are produced by colliding deuterium ions accelerated in a linear accelerator with a liquid lithium jet. The resulting neutrons are then used to assess how materials perform under the extreme conditions inside a fusion reactor. The objective of the LIDAR system is to monitor the depth variations of the liquid lithium jet target in real time, which is crucial to maintain the stability and efficiency of neutron generation. The research involves the selection and implementation of an amplitude-modulated (AM) LIDAR system, recognized for its high precision, which are vital to achieve the desired measurement accuracy. The DONES-FLUX project requires the system to achieve both precision and accuracy of less than 0.3 mm, with the aim of achieving less than 0.1 mm precision and accuracy in laboratory tests. A series of experiments were conducted to rigorously test the system, including characterization of the flat surface, measurements of distance between various surfaces, and evaluations of periodic surfaces The performance of the system remained stable across different scanning speeds and lock-in amplifier time constants, preserving precision even in dynamic situations. Significant challenges, such as the “smiley face” effect inherent in the scanning methodology, were effectively mitigated through quadratic fitting methods, further enhancing the system’s reliability. The system achieved an accuracy of less than 0.1 mm in controlled laboratory settings and demonstrated a precision of around 0.01 mm when measuring distances between different surfaces. However, when evaluating periodic surfaces, while the accuracy remained below 0.1 mm, the precision was around 0.2 mm due to the low voltage received from the surface, which increased with the time constant. This indicates the need for further optimization to improve the precision of periodic surfaces. Despite these challenges, the system performed efficiently with static targets, confirming its suitability for accurate depth measurements under controlled conditions. However, additional research is necessary to assess its performance with dynamic targets, such as the liquid lithium jet in operation within the IFMIF-DONES facility. The dynamic nature of the actual target in the testing facility environment introduces challenges that were not fully explored in this study, which warrants further investigation to ensure the system can maintain its precision and accuracy under real-world conditions. In summary, the developed LIDAR-based diagnostic system is well equipped for real-time monitoring of the lithium jet in a testing facility environment, providing a reliable and precise solution for depth measurement. The system not only meets the requirements of precision and accuracy, but also shows potential for further optimization, particularly in improving precision for periodic surfaces, and broader application in fusion diagnostics, making a significant contribution to the advancement of nuclear fusion technology |
|---|