The ArT\'eMiS wide-field submillimeter camera: preliminary on-sky performances at 350 microns

ArTeMiS is a wide-field submillimeter camera operating at three wavelengths simultaneously (200, 350 and 450 microns). A preliminary version of the instrument equipped with the 350 microns focal plane, has been successfully installed and tested on APEX telescope in Chile during the 2013 and 2014 austral winters. This instrument is developed by CEA (Saclay and Grenoble, France), IAS (France) and University of Manchester (UK) in collaboration with ESO. We introduce the mechanical and optical design, as well as the cryogenics and electronics of the ArTeMiS camera. ArTeMiS detectors are similar to the ones developed for the Herschel PACS photometer but they are adapted to the high optical load encountered at APEX site. Ultimately, ArTeMiS will contain 4 sub-arrays at 200 microns and 2x8 sub-arrays at 350 and 450 microns. We show preliminary lab measurements like the responsivity of the instrument to hot and cold loads illumination and NEP calculation. Details on the on-sky commissioning runs made in 2013 and 2014 at APEX are shown. We used planets (Mars, Saturn, Uranus) to determine the flat-field and to get the flux calibration. A pointing model was established in the first days of the runs. The average relative pointing accuracy is 3 arcsec. The beam at 350 microns has been estimated to be 8.5 arcsec, which is in good agreement with the beam of the 12 m APEX dish. Several observing modes have been tested, like On-The-Fly for beam-maps or large maps, spirals or raster of spirals for compact sources. With this preliminary version of ArTeMiS, we concluded that the mapping speed is already more than 5 times better than the previous 350 microns instrument at APEX. The median NEFD at 350 microns is 600 mJy.s1/2, with best values at 300 mJy.s1/2. The complete instrument with 5760 pixels and optimized settings will be installed during the first half of 2015.Comment: 11 pages, 11 figures. Presented at SPIE Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII, June 24, 2014. To be published in Proceedings of SPIE Volume 915

Interferential scanning grating position sensor operating in space at 4 K

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Digital revolution for the agroecological transition of food systems: A responsible research and innovation perspective

International audienceCONTEXTSo far, digital technology development in agriculture has mainly dealt with precision agriculture, often associated with conventional large-scale systems. The emergence of digital agriculture - based on the triptych of “new data sources / new processing methods / new inter-connection capacities (internet)” - opens up prospects for mobilizing digital technologies to accelerate the deployment of other forms of agriculture, such as agroecology. A specific research agenda must therefore be built to redirect researchers specialized in digital technologies towards these new issues. This construction is significant because digital technology and agroecology are disruptive innovations that shake up the actors' practices, agricultural innovation ecosystems, and value chains.OBJECTIVEAn interdisciplinary group of INRAE researchers (covering 10 scientific departments) was mandated to carry out this reflection, with the objective of developing a research agenda to better couple digitalization and agroecology, in order to pave the way for responsible digital farming. The group used the framework of responsible research and innovation.METHODOver 18 months, the group met monthly by video-conference, to overcome the interdisciplinarity barrier, and at three face-to-face seminars, where creative design exercises were carried out (based on a world café format, and “remember the future” method). This work gave rise to three prospective lines of research aimed at putting digitalization at the service of agroecology and local food systems. These topics prioritize research that fosters innovations in digital technology, as well as organisations and policies that (1) accelerate the agroecological transition on the farm and in the territories, (2) manage the territories as commons, (3) empower farmers and consumers. Then, the group examined these three prospective lines of research from an RRI perspective as well as three current research topics on digital agriculture (digital soil mapping, precision agriculture, technologies for food wastage reduction).RESULTS AND CONCLUSIONSThis work allowed us to highlight the gaps between current research on digital agriculture and the RRI expectations, and the tensions (between rationalization and diversity of farming systems, between complexity of agroecological systems and the need for simplification of models, and finally between data speculation and frugality). We were also able to refine the specific scientific questions of each prospective line of research and finally to draw attention to the key levers that will have to be integrated if these research efforts are to be approached from an RRI perspective.SIGNIFICANCEThis contribution shows RRI can be used not only to reflect on research practices but also as a framework to build a research agenda paving the way for responsible digital agriculture

Imaging FTS for Herschel SPIRE

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Imaging FTS for Herschel SPIRE

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Imaging FTS for Herschel SPIRE

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BRAHMS: polarimetric bolometer arrays for the SPICA observatory camera (Conference Presentation)

International audienceIn the last decades, a very large effort has been made to measure, with high sensitivity, the intensity and spectral contents of millimetric (mm) and submillimetric (submm) light from the Universe. Today this picture is in the way to be routinely completed by polarization measurements that give access to previously hidden processes, for example the traces of primordial gravitational waves in the case of CMB (mainly mm), or the effect of magnetic field for star formation mechanisms (submm and mm optical ranges). The classical way to measure the light polarization is to split the two components by a polarizer grid and record intensities with two conjugated detection setups. This approach implies the deployment of a complex instrument system, very sensitive to external constraints (vibrations, alinement, thermal expansion…), or internal ones: determine low degrees of polarization implies a large increase in sensitivity when compared with intensity measurements. The need of detector arrays, with in pixel polarization measurement capabilities, has been well understood for years: all the complexity being reported at the focal plane level. Subsequently, the instrument integration, verification and tests procedure is considerately alleviated, specially for space applications.All silicon bolometer arrays using the same micromachining techniques than the Herschel PACS modules are well suited for this type of development. New thermometers doped for 50 mK operations permit to achieve, with a new design, sensitivities close to the aW/√Hz. It is based on all-legs bolometers (ALB), where the absorbing, insulating and thermometric functions are made by the same suspended silicon structure. This ALB structure, with in this case a spiral design, permits to separate the absorption of the two electromagnetic components of the light polarization. Each pixel consists of four bolometer divided in two pairs, each sensitive to one direction of polarization. This permits to combine the bolometer bridges in a fully differential global structure with a Wheatstone bridge arrangement. Total intensity and polarization unbalance are available directly at the detector level, thanks to a cold readout circuit integrated in the detector structure. This combination of functions is achieved by above IC manufacture techniques (IC for Integrated Circuit).All these developments take place in the prospect of the joint JAXA-ESA SPICA project, to equip a 1344 pixels polarimetric and imaging camera covering three spectral bands (100, 200 and 350 µm)

Second generation of portable gamma camera based on Caliste CdTe hybrid technology

International audienceIn the framework of a national funded program for nuclear safety, a first prototype of portable gamma camera was built and tested. It integrates a Caliste-HD CdTe-hybrid detector designed for space X-ray astronomy coupled with a new system-on-chip based acquisition system (FPGA and ARM microprocessor) and thermo-electrical coolers for a use at room temperature. The complete gamma part of the camera fits in a volume of for a mass lower than 1 kg and a power consumption lower than 10 W. Localization and spectro-identification of radionuclides in a contaminated scene were demonstrated during several test campaigns. A new generation of system is under development taking into account feedback experience from in-situ measurements and integrating a new generation of sensor cost-optimized by industrial applications called Caliste-O. Caliste-O holds a 16x16 pixel detector of 14x14 mm2 and 2 mm thick with 8 full-custom front-end IDeF-X HD ASICs. Two prototypes were fabricated and tested. The paper will present the results of in-situ measurements with the first gamma camera, the spectroscopic performance of Caliste-O and the design of the second generation of gamma camera which aims for real time imaging and spectro-identification

AIRS: ARIEL IR spectrometer status

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