Exploring cosmic rays at the highest-energy frontier with the Pierre Auger observatory

The Pierre Auger Observatory studies the most energetic cosmic rays arriving at Earth, those with energies from 10(17) eV up to 10(20) eV and beyond. In continuous operation since 2004, the Observatory employs two complementary detection techniques for measuring air showers induced by those extremely energetic particles. For the past few years new detectors and techniques are being added in order to augment the sensitivity of the measurements. Data accumulated in ten years have led to major advances in our knowledge of the origin and nature of cosmic rays. We present a summary of the latest results for the spectrum of cosmic rays, their arrival directions and composition, as well as the challenges for the future operation of the Observatory.953rd International Conference on New Frontiers in Physics (ICNFP)2015-08GreciaKolymbar

Exploring Cosmic Rays At The Highest-energy Frontier With The Pierre Auger Observatory

The Pierre Auger Observatory studies the most energetic cosmic rays arriving at Earth, those with energies from 10(17) eV up to 10(20) eV and beyond. In continuous operation since 2004, the Observatory employs two complementary detection techniques for measuring air showers induced by those extremely energetic particles. For the past few years new detectors and techniques are being added in order to augment the sensitivity of the measurements. Data accumulated in ten years have led to major advances in our knowledge of the origin and nature of cosmic rays. We present a summary of the latest results for the spectrum of cosmic rays, their arrival directions and composition, as well as the challenges for the future operation of the Observatory.9

Exploring cosmic rays at the highest-energy frontier with the Pierre Auger Observatory

The Pierre Auger Observatory studies the most energetic cosmic rays arriving at Earth, those with energies from 1017 eV up to 1020 eV and beyond. In continuous operation since 2004, the Observatory employs two complementary detection techniques for measuring air showers induced by those extremely energetic particles. For the past few years new detectors and techniques are being added in order to augment the sensitivity of the measurements. Data accumulated in ten years have led to major advances in our knowledge of the origin and nature of cosmic rays. We present a summary of the latest results for the spectrum of cosmic rays, their arrival directions and composition, as well as the challenges for the future operation of the Observatory

Autonomous RPCs for a Cosmic Ray ground array

We report on the behaviour of Resistive Plate Chambers (RPC) developed for muon detection in ultra-high energy cosmic ray (UHECR) experiments. The RPCs were developed for the MARTA project and were tested on field conditions. These RPCs cover an area of $1.5 \times 1.2\,{m^2}$ and are instrumented with 64 pickup electrodes providing a segmentation better than $20\,$cm. By shielding the detector units with enough slant mass to absorb the electromagnetic component in the air showers, a clean measurement of the muon content is allowed, a concept to be implemented in a next generation of UHECR experiments. The operation of a ground array detector poses challenging demands, as the RPC must operate remotely under extreme environmental conditions, with limited budgets for power and minimal maintenance. The RPC, DAQ, High Voltage and monitoring systems are enclosed in an aluminium-sealed case, providing a compact and robust unit suited for outdoor environments, which can be easily deployed and connected. The RPCs developed at LIP-Coimbra are able to operate using a very low gas flux, which allows running them for few years with a small gas reservoir. Several prototypes have already been built and tested both in the laboratory and outdoors. We report on the most recent tests done in the field that show that the developed RPCs have operated in a stable way for more than 2 years in field conditions.Comment: To appear in the proceedings of the 35th International Cosmic Ray Conference (ICRC2017), Busan, South Korea. Presented by R. Concei\c{c}\~{a}o. 8 page

Autonomous RPCs for a Cosmic Ray ground array

We report on the behaviour of Resistive Plate Chambers (RPC) developed for muon detection in ultra-high energy cosmic ray (UHECR) experiments. The RPCs were developed for the MARTA project and were tested on field conditions. These RPCs cover an area of $1.5 \times 1.2\,{m^2}$ and are instrumented with 64 pickup electrodes providing a segmentation better than $20\,$cm. By shielding the detector units with enough slant mass to absorb the electromagnetic component in the air showers, a clean measurement of the muon content is allowed, a concept to be implemented in a next generation of UHECR experiments. The operation of a ground array detector poses challenging demands, as the RPC must operate remotely under extreme environmental conditions, with limited budgets for power and minimal maintenance. The RPC, DAQ, High Voltage and monitoring systems are enclosed in an aluminium-sealed case, providing a compact and robust unit suited for outdoor environments, which can be easily deployed and connected. The RPCs developed at LIP-Coimbra are able to operate using a very low gas flux, which allows running them for few years with a small gas reservoir. Several prototypes have already been built and tested both in the laboratory and outdoors. We report on the most recent tests done in the field that show that the developed RPCs have operated in a stable way for more than 2 years in field conditions.Peer Reviewe

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO