The calma station and a new data acquisition system for neutron monitors

Abstract

Neutron monitors are state-of-the-art ground-based detectors designed to measure high-energy particles that arrive to the Earth’s atmosphere mainly from the outside of the Solar System. Since its initial conception by Professor A. Simpson, in the University of Chicago in 1948, it has undergone different upgrades, not in its basic conception but in the new technologies available for its construction, distribution and analysis of its data. The combination of new databases technologies and the Internet network have made possible to unify and centralize the data provided by many stations around the planet in the so called Neutron Monitor Database (NMDB). This project has open a new path in the research of Solar Physics, Energetic Particles and Earth-Sun interaction and Cosmic Rays. This thesis work stars by using the data provided by the NMDB to study the observable effects of Interplanetary Coronal Mass Ejections on ground level neutron monitor counting rates. The data from the NMDB helped us to provide a framework of requirements for a new data acquisition design, and the results are also included in this document. Next in this work, the design and construction of the new Castilla-La Mancha Neutron Monitor, CaLMa is presented. This is a NM64-type neutron monitor located in Guadalajara (Spain), 40◦38′32.2”N, 3 ◦9 ′44.4”W at 708 m above sea level, and it has a calculated vertical cut-off rigidity of 6.95 GV. This station is integrated in the Neutron Monitor Database and provides high-resolution 1-minute real time data, that is publicly available through the NMDB distribution channels. Along with the CaLMa Neutron Monitor, a new data acquisition system has also been designed from scratch to address obsolescense problems and to provide new features by means of applying FPGA-based technologies. This new system has been already running in other stations, so a comparative data analysis has also been provided from old and new acquisitions systems. This will allow us to performs validation analysis for the new system