This paper is devoted to the study of the most suitable protocols needed to verify the lightning protection and ground resistance quality in a large-scale scientific facility located on a site with high risk of lightn...This paper is devoted to the study of the most suitable protocols needed to verify the lightning protection and ground resistance quality in a large-scale scientific facility located on a site with high risk of lightning strikes. We illustrate this work by reviewing a case study: the largest telescopes of the Northern Hemisphere Cherenkov Telescope Array, CTA-N. This array hosts sensitive and high-speed optoelectronics instrumentation and sits on a clear, free from obstacle terrain at around 2400 m above sea level. The site offers a top-quality sky but also features challenging conditions for a lightning protection system: the terrain is volcanic and has electrical resistivities well above 1 kOhm·m. In addition, the environment often exhibits humidities well below 5%, and strong winds pose challenging conditions. On the other hand, the </span><span style="font-family:Verdana;">high complexity of a Cherenkov telescope structure does not allow a straightforward</span><span style="font-family:Verdana;"> application of lightning protection standards. We describe here how the risk assessment of direct strike impacts was made and how contact voltages and ground system were both tested. Finite Element Simulation (COMSOL Multiphysics) has been used to estimate the current flowing through the parts of the earthing system designed for the telescopes in the case of a direct strike impact. This work is intended to provide assistance to scientists and managers involved in the construction of scientific installations, particularly those in charge of defining verifiable reliability and safety requirements for lightning protection.展开更多
Large-scale astrophysical facilities have become increasingly relevant in certain key areas of scientific research<span style="white-space:normal;font-size:10pt;font-family:;" "=""> <...Large-scale astrophysical facilities have become increasingly relevant in certain key areas of scientific research<span style="white-space:normal;font-size:10pt;font-family:;" "=""> </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">but typically require strong financial investments. It is</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">,</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> therefore</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">,</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> crucial to gain a deep understanding </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">of</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> what could be a foreseeable lifespan of a given instrument before providing the required fund to build it. In this paper</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">,</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> we intend to contribute to this understanding with a study of the lifespan of past, current and future observatories and telescopes. The methodology has been based on the compilation of relevant data from twenty telescopes, three of them mounted on space satellites and the other seventeen distributed worldwide. An analysis of the main limiting factors that affect the lifetime of an astrophysical facility is also presented</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">.</span>展开更多
Large-scale scientific instruments strongly support top-level research all around the world. Besides their intrinsic merits, they often play a valuable role as pathfinders for developing and testing instrumentation an...Large-scale scientific instruments strongly support top-level research all around the world. Besides their intrinsic merits, they often play a valuable role as pathfinders for developing and testing instrumentation and as training grounds for young researchers. Strategies and roadmaps for these facilities have become a priority for a number of private and public funding organizations. Despite the large amount of mature work done in the industrial arena, it is difficult to find documents providing clear and concise orientation on how to prevent or minimize the damage caused by electrostatic discharges (ESD) in research infrastructure. This paper aims to gather all this information to develop a static charge control plan for a large-scale scientific facility. The specific case of the static charge control plan for the installation of CTA-LST telescopes is added as an example and verification of the actual applicability of the measures proposed in this document, providing static charge in human body monitoring measurements. Specific tests performed on equipment with ESD sensitive components are also described, which helped to assess any possible damage.展开更多
文摘This paper is devoted to the study of the most suitable protocols needed to verify the lightning protection and ground resistance quality in a large-scale scientific facility located on a site with high risk of lightning strikes. We illustrate this work by reviewing a case study: the largest telescopes of the Northern Hemisphere Cherenkov Telescope Array, CTA-N. This array hosts sensitive and high-speed optoelectronics instrumentation and sits on a clear, free from obstacle terrain at around 2400 m above sea level. The site offers a top-quality sky but also features challenging conditions for a lightning protection system: the terrain is volcanic and has electrical resistivities well above 1 kOhm·m. In addition, the environment often exhibits humidities well below 5%, and strong winds pose challenging conditions. On the other hand, the </span><span style="font-family:Verdana;">high complexity of a Cherenkov telescope structure does not allow a straightforward</span><span style="font-family:Verdana;"> application of lightning protection standards. We describe here how the risk assessment of direct strike impacts was made and how contact voltages and ground system were both tested. Finite Element Simulation (COMSOL Multiphysics) has been used to estimate the current flowing through the parts of the earthing system designed for the telescopes in the case of a direct strike impact. This work is intended to provide assistance to scientists and managers involved in the construction of scientific installations, particularly those in charge of defining verifiable reliability and safety requirements for lightning protection.
文摘Large-scale astrophysical facilities have become increasingly relevant in certain key areas of scientific research<span style="white-space:normal;font-size:10pt;font-family:;" "=""> </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">but typically require strong financial investments. It is</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">,</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> therefore</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">,</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> crucial to gain a deep understanding </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">of</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> what could be a foreseeable lifespan of a given instrument before providing the required fund to build it. In this paper</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">,</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> we intend to contribute to this understanding with a study of the lifespan of past, current and future observatories and telescopes. The methodology has been based on the compilation of relevant data from twenty telescopes, three of them mounted on space satellites and the other seventeen distributed worldwide. An analysis of the main limiting factors that affect the lifetime of an astrophysical facility is also presented</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">.</span>
文摘Large-scale scientific instruments strongly support top-level research all around the world. Besides their intrinsic merits, they often play a valuable role as pathfinders for developing and testing instrumentation and as training grounds for young researchers. Strategies and roadmaps for these facilities have become a priority for a number of private and public funding organizations. Despite the large amount of mature work done in the industrial arena, it is difficult to find documents providing clear and concise orientation on how to prevent or minimize the damage caused by electrostatic discharges (ESD) in research infrastructure. This paper aims to gather all this information to develop a static charge control plan for a large-scale scientific facility. The specific case of the static charge control plan for the installation of CTA-LST telescopes is added as an example and verification of the actual applicability of the measures proposed in this document, providing static charge in human body monitoring measurements. Specific tests performed on equipment with ESD sensitive components are also described, which helped to assess any possible damage.