J. A. Morales de los Ríos

Observation of ultra-high energy cosmic rays in cloudy conditions by the space-based JEM-EUSO Observatory

JEM-EUSO is a space observatory that will be located on-board the Japanese Experiment Module at the International Space Station. It will observe Extensive Air Showers (EAS) induced by ultra-high energy cosmic rays using the Earths atmosphere as detector. In addition to clear sky observations, EAS are also observable in cloudy conditions if a sufficiently large part of the EAS development occurs above the cloud. The atmospheric monitoring system plays a fundamental role in our understanding of the atmospheric conditions in the field of view of the telescope.

Observation of Ultra-High Energy Cosmic Rays in cloudy conditions by the JEM-EUSO Space Observatory

Source of Ultra-high Energy Cosmic Rays (several times 10 19 eV) are still unidentified. Overcoming their extremely small fluxes, a detector with huge observation are as is needed to investigate the energy and arrival direction distribution of EECRs. JEM-EUSO is a unique experiment that will be located in the International Space Station to observe extensive air showers (EAS) by monitoring night part of Earth atmosphere. In addition to clear sky condition, the extensive air showers in cloudy condition are also observable by taking advantage of the certain fraction of EAS develop above the cloud. In the preset work, using Monte Carlo simultions for test clouds, the cloud impact to the trigger efficiency was estimated taking into account the statistics of cloud property.

Proposal of a Computing Model Using GRID Resources for the JEM-EUSO Space Mission

For High Energy Physics (HEP) experiments the huge amount of data and complex analysis algorithms require the use of advanced GRID computational resources. Therefore, an exhaustive analysis of computational requirements and resources, in the frame of the GRID architecture, intended for the JEM-EUSO space mission software and computing infrastructure has been performed. Moreover solutions to account for the software and data repositories as well as a proper administrative organization are pointed out.

Thin and thick cloud top height retrieval algorithm with the Infrared Camera and LIDAR of the JEM-EUSO Space Mission

The origin of cosmic rays have remained a mistery for more than a century. JEM-EUSO is a pioneer space-based telescope that will be located at the International Space Station (ISS) and its aim is to detect Ultra High Energy Cosmic Rays (UHECR) and Extremely High Energy Cosmic Rays (EHECR) by observing the atmosphere. Unlike ground-based telescopes, JEM-EUSO will observe from upwards, and therefore, for a properly UHECR reconstruction under cloudy conditions, a key element of JEM-EUSO is an Atmospheric Monitoring System (AMS). This AMS consists of a space qualified bi-spectral Infrared Camera, that will provide the cloud coverage and cloud top height in the JEM-EUSO Field of View (FoV) and a LIDAR, that will measure the atmospheric optical depth in the direction it has been shot. In this paper we will explain the effects of clouds for the determination of the UHECR arrival direction. Moreover, since the cloud top height retrieval is crucial to analyze the UHECR and EHECR events under cloudy conditions, the retrieval algorithm that fulfills the technical requierements of the Infrared Camera of JEM-EUSO to reconstruct the cloud top height is presently reported.

Design of the front end electronics for the infrared camera of JEM-EUSO, and manufacturing and verification of the prototype model

The Japanese Experiment Module (JEM) Extreme Universe Space Observatory (EUSO) will be launched and attached to the Japanese module of the International Space Station (ISS). Its aim is to observe UV photon tracks produced by ultra-high energy cosmic rays developing in the atmosphere and producing extensive air showers. The key element of the instrument is a very wide-field, very fast, large-lense telescope that can detect extreme energy particles with energy above 1019 eV. The Atmospheric Monitoring System (AMS), comprising, among others, the Infrared Camera (IRCAM), which is the Spanish contribution, plays a fundamental role in the understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. It is used to detect the temperature of clouds and to obtain the cloud coverage and cloud top altitude during the observation period of the JEM-EUSO main instrument. SENER is responsible for the preliminary design of the Front End Electronics (FEE) of the Infrared Camera, based on an uncooled microbolometer, and the manufacturing and verification of the prototype model. This paper describes the flight design drivers and key factors to achieve the target features, namely, detector biasing with electrical noise better than 100μV from 1Hz to 10MHz, temperature control of the microbolometer, from 10°C to 40°C with stability better than 10mK over 4.8hours, low noise high bandwidth amplifier adaptation of the microbolometer output to differential input before analog to digital conversion, housekeeping generation, microbolometer control, and image accumulation for noise reduction. It also shows the modifications implemented in the FEE prototype design to perform a trade-off of different technologies, such as the convenience of using linear or switched regulation for the temperature control, the possibility to check the camera performances when both microbolometer and analog electronics are moved further away from the power and digital electronics, and the addition of switching regulators to demonstrate the design is immune to the electrical noise the switching converters introduce. Finally, the results obtained during the verification phase are presented: FEE limitations, verification results, including FEE noise for each channel and its equivalent NETD and microbolometer temperature stability achieved, technologies trade-off, lessons learnt, and design improvement to implement in future project phases.

Microbolometer characterization with the electronics prototype of the IRCAM for the JEM-EUSO mission

JEM-EUSO is a space observatory that will be attached to the Japanese module of the International Space Station (ISS) to observe the UV photon tracks produced by Ultra High Energy Cosmic Rays (UHECR) interacting with atmospheric nuclei. The observatory comprises an Atmospheric Monitoring System (AMS) to gather data about the status of the atmosphere, including an infrared camera (IRCAM) for cloud coverage and cloud top height detection. This paper describes the design and characterization tests of IRCAM, which is the responsibility of the Spanish JEM-EUSO Consortium. The core of IRCAM is a 640x480 microbolometer array, the ULIS 04171, sensitive to radiation in the range 7 to 14 microns. The microbolometer array has been tested using the Front End Electronics Prototype (FEEP). This custom designed electronics corresponds to the Breadboard Model, a design built to verify the camera requirements in the laboratory. The FEEP controls the configuration of the microbolometer, digitizes the detector output, sends data to the Instrument Control Unit (ICU), and controls the microbolometer temperature to a 10 mK stability. Furthermore, the FEEP allows IRCAM to preprocess images by the addition of a powerful FPGA. This prototype has been characterized in the laboratories of Instituto de Astrofisica de Canarias (IAC). Main results, including detector response as a function of the scene temperature, NETD and Non-Uniformity Correction (NUC) are shown. Results about thermal resolution meet the system requirements with a NETD lower than 1K including the narrow band filters which allow us to retrieve the clouds temperature using stereovision algorithms.

The SPAS-UAH Cluster for the JEM-EUSO Computing Model

The JEM-EUSO space observatory will be launched and attached to the Japanese module of the International Space Station (ISS) in 2016. Its aims is to observe UV photon tracks produced by Ultra High Energy Cosmic Rays (UHECR) and Extremely High Energy Cosmic Rays (EHECR) developing in the atmosphere and producing Extensive Air Showers (EAS). JEM-EUSO will use our atmosphere as a huge calorimeter, to detect the electromagnetic and hadronic components of the EAS. For High Energy Physic (HEP) experiments the huge amount of data and complex analysis algorithms require the use of advanced GRID computational resources. Therefore a complete infrastructure is needed for the simulation and data analysis, in the frame of the GRID architecture, and computing infrastructure, intended for the JEM-EUSO space mission software. Moreover solutions to account for a complete installed cluster system, with the software and data repositories, as well as a many other details are pointed out.