The EUSO-balloon instrument and an analysis of its photo-detecting efficiency

JEM-EUSO (Extreme Universe Space Observatory on Japanese Experiment Module) est une expérience basée sur un télescope spatial d’optique diffractive, avec des lentilles de Fresnel, qui sera installé sur l’ISS en 2020. Il a comme but l’étude des UHECR et vise à améliorer d’un facteur de 10 les mesures actuelles de l’Observatoire Pierre-Auger. Le télescope EUSO-Balloon, qui a été validé technologiquement en 2014 a été le premier prototype intégrant l’ensemble de la chaîne de détection du télescope JEM-EUSO. Le principe de détection est basé sur la capture des photons UV individuels (photodétection) produits par fluorescence lors de l’interaction d’EAS avec l’atmosphère terrestre. Cette lumière est si faible qu’elle nécessite un instrument avec une efficacité de 100% pour la détection d’un photon. Le travail présenté dans ce manuscrit a porté sur toutes les étapes du projet EUSO-Balloon. Un procédé original de récupération de l’information des pixels avec une sensibilité faible a été développé. Le procédé consiste à utiliser une courbe (s-curve) générée par la modification du seuil de discrimination des signaux analogiques provenant des anodes des MAPMTs. Elle est valable pour tous les télescopes EUSO et sera utile dans l’espace, où la manipulation de l’appareil est limitée.JEM-EUSO (Extreme Universe Space Observatory on Japanese Experiment Module) is an experiment based on a diffractive optical telescope, with Fresnel lenses, that will be installed on the ISS in 2020. It aims to study the UHECR, improving by a factor of 10 the current measurements of the Pierre-Auger Observatory. The EUSO-Balloon telescope, technically validated in 2014, was the first prototype with the entire detection chain of the JEM-EUSO telescope. The detection principle is based on the capture of individual UV photons (photodetection) produced by fluorescence when the EAS interact with the Earth’s atmosphere. The fluorescence light is so low that an instrument with 100% efficiency for the detection of a photon, is required. The work presented in this manuscript has dealt with all the steps of EUSO-Balloon project. An original procedure has been developed to recover the information from pixels with low sensitivity. The method consists in using a curve generated by the modification of the threshold used to discriminate the analog signals produced by the anodes of the MAPMTs. It is valid for all EUSO telescopes and will be most useful in space where the manipulation of the apparatus is limited

L’instrument EUSO-Balloon et analyse de son efficacité de photo-détection

JEM-EUSO (Extreme Universe Space Observatory on Japanese Experiment Module) is an experiment based on a diffractive optical telescope, with Fresnel lenses, that will be installed on the ISS in 2020. It aims to study the UHECR, improving by a factor of 10 the current measurements of the Pierre-Auger Observatory. The EUSO-Balloon telescope, technically validated in 2014, was the first prototype with the entire detection chain of the JEM-EUSO telescope. The detection principle is based on the capture of individual UV photons (photodetection) produced by fluorescence when the EAS interact with the Earth’s atmosphere. The fluorescence light is so low that an instrument with 100% efficiency for the detection of a photon, is required. The work presented in this manuscript has dealt with all the steps of EUSO-Balloon project. An original procedure has been developed to recover the information from pixels with low sensitivity. The method consists in using a curve generated by the modification of the threshold used to discriminate the analog signals produced by the anodes of the MAPMTs. It is valid for all EUSO telescopes and will be most useful in space where the manipulation of the apparatus is limited.JEM-EUSO (Extreme Universe Space Observatory on Japanese Experiment Module) est une expérience basée sur un télescope spatial d’optique diffractive, avec des lentilles de Fresnel, qui sera installé sur l’ISS en 2020. Il a comme but l’étude des UHECR et vise à améliorer d’un facteur de 10 les mesures actuelles de l’Observatoire Pierre-Auger. Le télescope EUSO-Balloon, qui a été validé technologiquement en 2014 a été le premier prototype intégrant l’ensemble de la chaîne de détection du télescope JEM-EUSO. Le principe de détection est basé sur la capture des photons UV individuels (photodétection) produits par fluorescence lors de l’interaction d’EAS avec l’atmosphère terrestre. Cette lumière est si faible qu’elle nécessite un instrument avec une efficacité de 100% pour la détection d’un photon. Le travail présenté dans ce manuscrit a porté sur toutes les étapes du projet EUSO-Balloon. Un procédé original de récupération de l’information des pixels avec une sensibilité faible a été développé. Le procédé consiste à utiliser une courbe (s-curve) générée par la modification du seuil de discrimination des signaux analogiques provenant des anodes des MAPMTs. Elle est valable pour tous les télescopes EUSO et sera utile dans l’espace, où la manipulation de l’appareil est limitée

Using two-photon statistical contribution in the detection of telescopes EUSO

International audienceThe Extreme Universe Space Observatory onboard Japanese Experiment Module (JEM-EUSO) is the future space observatory will be installed on the International Space Station (ISS) to study the comic rays of ultra high energy (UHECR). The Photo detector module (PDM) of telescope (JEM-EUSO) is characterized by high sensitivity detection that allows you to detect single photons of UV backgraund. The telescope EUSO-Balloon was the first prototype to validate JEM-EUSO chain detection in extreme environmental conditions. The post flight analysis of the efficiency of EUSO-Balloon detection showed that only 30 % of the pixels met the technical requirements for the study of EAS et detection of UV background (required efficiency of photo-detection > 12%). The next prototypes of JEM-EUSO have as their mission the Extensive Air Shower (EAS) detection of UHECR with energies > 10 20 eV . An requirement for this, it is the validation of the systems trigger, which distinguish this luminescence over background noise UV. These systems trigger requires that all pixels are operational, this means, these pixels must be able to detect events corresponding to one photo-electron (pe) per gate time unit (GTU=2, 5 μs ). This work is about a method to offset, to some extent, the problem of efficiency loss of detection channels. The formation of a pulse signal corresponding to 1 pe is governed by the Poisson distribution, this means that there are pulses formed by the pil-up of two or more pulses. That may eventually be used to estimate the efficiency of pixels with weak performance

Performance of the EUSO-Balloon UV Camera

International audienceJEM-EUSO [1] is intended to be a space-borne fruorescence te lescope onboard of JEM/EF (Japanese Experimental Modeul/Exposure Facility) on the International Space Station (ISS). The main goal of the JEM-EUSO project is to detect the Extensive A ir Showers (EAS) produced by the Extreme Energy Cosmic Rays (EECRs) with energies above 1 0 19 eV from the extragalactic objects. As a pathfinder, the JEM-EUSO collaboration is curr ently developing a balloon-borne fluorescence telescope experiment, called EUSO-Balloon, f unded by CNES, the French space agency. It will perform end-to-end tests of the JEM-EUSO sub systems and instrumental concept, and measure the UV background for space-based EECR detector s. It involves several French in- stitutes (LAL, APC and IRAP) as well as several key institute s of the JEM-EUSO collaboration. The EUSO-Balloon instrument consists of an UV telescope and an infrared camera. The UV telescope will be operated at an altitude of 40 km to observe t he background and possibly signal photons in the fluorescence UV range (290-430 nm), which are e mitted along shower tracks gen- erated by ultra high energy cosmic rays with energies above 1 0 18 eV interacting with the earth’s atmosphere. The balloon experiment will be equipped with el ectronics and acquisition systems, as close as possible to the ones designed for the UV telescope of main JEM-EUSO instrument. The past years have been devoted to the design, the fabricati on and the tests of the prototype boards of the PDM, of the digital processor, and the flight mod els of optics, electronics and the IR camera for EUSO-Balloon. Here we focus on the PDM, the core element of the JEM-EUSO foca l surface. We first describe all key items of the PDM, from the photodetectors to the FPGA b oard, the first stage of the data processing (DP). We then report on the tests carried out on th e integration to assess their func- tionality and their suitability for a balloon mission

EUSO-Balloon: Observation and Measurement of Tracks from a Laser in a Helicopter

International audienceEUSO-Balloon is a prototype detector of the Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO). EUSO-Balloon was flown successfully as a balloon payload from the Timmins Stratospheric Balloon Launch Facility in Ontario, Canada on 2014 August 24-25 at an altitude of 38 km. To simulate the optical signatures of UV fluorescence photons emitted from cosmic ray air showers generated in the atmosphere, a pulsed UV laser and two UV flashers (LED and Xe) were used. These sources were fired in the instrument field of view for about 2 hours from a helicopter that circled at an altitude of 3 km under the balloon. UV signals were effectively detected, including 270 laser track events. We describe the helicopter laser system and the geometric reconstruction of the laser events that were generated by this system. We report here on the reconstruction of the laser events starting from the information contained in the observed tracks. We note that this work represents the first observation and measurement of aircraft based laser tracks by an optical fluorescence detector flown at near space altitudes