Drafting an Electrostatic Charge Control Plan for a Large Scale Scientific Instrument: Guidelines and a Case Study

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.

Geometry and optics calibration of WFCTA prototype telescopes using star light

The Large High Altitude Air Shower Observatory （LHAASO） project is proposed to study high energy gamma ray astronomy （40 GeV–1 PeV） and cosmic ray physics （20 TeV–1 EeV）. The wide field of view Cherenkov telescope array, as a component of the LHAASO project, will be used to study the energy spectrum and composition of cosmic rays by measuring the total Cherenkov light generated by air showers and the shower maximum depth. Two prototype telescopes have been in operation since 2008. The pointing accuracy of each telescope is crucial for the direction reconstruction of the primary particles. On the other hand, the primary energy reconstruction relies on the shape of the Cherenkov image on the camera and the unrecorded photons due to the imperfect connections between the photomultiplier tubes. UV bright stars are used as point-like objects to calibrate the pointing and to study the optical properties of the camera, the spot size and the fractions of unrecorded photons in the insensitive areas of the camera.

Energy spectrum of cosmic protons and helium nuclei by a hybrid measurement at 4300 m a.s.l.

The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called ＂knee＂ by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber （RPC） array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range （100-700 TeV）. The observed energy spectrum is compatible with a single power law with index γ=-2.63±0.06.

TeV astronomy

With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes （IACTs）, and highlight astrophysical implications of the results obtained within recent years.