UN GENERATORE DI PETTINE DI FREQUENZE PER L’ECCITAZIONE DI RIVELATORI DI FOTONI A BASSA ENERGIA

Il lavoro qui presentato, che nasce dalla collaborazione tra l’LNTS (Laboratorio Nuove Tecnologie e Strumenti) dell’INGV e il Dipartimento di Fisica dell’Università di Roma “La Sapienza”, descrive lo strumento realizzato per fornire il pettine di frequenze atto ad eccitare un sistema sperimentale per otto risuonatori KID. In tale sistema il pettine di frequenze verrà traslato nella banda di frequenza dei KIDs (nell’ordine dei GHz) per poterne effettuare l’eccitazione e quindi riportato nella banda iniziale per effettuarne l’acquisizione e l’analisi

Pegaso: an ultra-light long duration stratospheric

Launched from the Mario Zuccelli Station (Baia Terra Nova) in Antarctica during the 2005/06 austral summer, the PEGASO-D payload lifted into the stratospheric anticyclone over the southern polar region. This effort marks the first Long Duration Scientific payload to be launched from this location and is the fourth such payload launched in the polar regions. Performing in the framework of the NOBILE/AMUNDSEN collaborative LDB development between ASI-ARR. The Italian Institute of Geophysics and Volcanology (INGV), with the sponsorship of the Italian Antarctic Program (PNRA) and the Italian Space Agency (ASI),designed and built the Ultra-Light system together with three Universities in Italy. The Pegaso program has been created to investigate the Earth magnetic field and provide a precursor series of small payload launches for the bigger LDB program such as OLIMPO, BOOMERanG and BArSPOrt through this collaboration between ASI and ARR. The Italian scientific community, aware of the big advantages that LDB balloons can offer to their experiments, proposed to extend the LDB program to Southern polar regions, besides performing launches from the newly initiated Nobile/Amundsen Stratospheric Balloon Center in Svalbard, Norway.Three PEGASO (Polar Explorer for Geomagnetics And other Scientific Observations) payloads have been launched from the Svalbard (No) in collaboration with Andoya Rocket Range, ASI and ISTAR (Operations and logistics) during the past two northern summers. These stratospheric (altitude m.35000) small 10kmc balloons have floated in the stratosphere between 14 to 39 days measuring the magnetic field of polar regions, by means of a 3-axys-fluxgate magnetometer, during a three year campaign. The study of the magnetic field and its variations is done through permanent observatories. They provide us with high quality data but their spatial distribution is not quite regular, specially in Antarctica due to logistic difficulties. The coverage is improved through marine and aeromagnetic surveys, and also through satellite missions. There exists nevertheless a gap in the wavelengths of the magnetic field represented by these kind of measurements. Satellite data are too far away from Earth's surface to individuate wavelengths lower than 1000 km, and near-ground sur- veys are not able to represent wavelengths longer than the dimensions of the surveyed area. Moreover, there is a region empty of data around the geographical pole for the satellite measurements. The size of these gaps depends on the orbital parameters, but it can reach up to 10 degrees around the pole. PEGASO allows to bridge this gap in the measurements of the magnetic field. Surveys carried out at 35 km height allow the study of crustal anomalies in the range between, we can say, 60 and 1000 km. Taking into account that pathfinders (smaller non-recoverable balloon systems) are usually sent to explore the atmospheric currents, the use of PEGASO as pathfinder allows us to obtain all these results at a very affordable cost. The PEGASO payload was also developed as a single source system integrating science, housekeeping and operational control of the entire balloon borne configuration.Satellite telemetry sent the scientific (magnetometric) data, house-keeping (temperature, solar panel voltage and current, altitude and time) and telecommand (four ballast, two parachute release system, system reset), and powered the terminate system. Data flows through the IRIDIUM telephone service. The onboard systems were kept inside a vessel (white painted and pressurizzed vessel due to power dissipation) except for external flexible solar panels and magnetometer, attached to an external boom. Two redundant tracking systems have been used: a first GPS was integrated inside the on-board telemetry system, necessary to reconstruct position and time of scientific data, while an independent GPS-ARGOS system gave the balloon trajectory, including its descent. Continuous trajectory predictions were made during the missions; they have been necessary, in particular, for the flight safety requirements of the northern hemisphere. The evaluation of the statistical error is proposed. The PEGASO payload was developed to be a light, cost effective way to explore the potential of Ultra-Light Long Duration Ballooning for science as well as an introduction to the earth-space possibilities for students.PublishedBeijing, China1A. Geomagnetismo e Paleomagnetism

The primary cosmic ray composition between 10**15 and 10**16 eV from Extensive Air Showers electromagnetic and TeV muon data

The cosmic ray primary composition in the energy range between 10**15 and 10**16 eV, i.e., around the "knee" of the primary spectrum, has been studied through the combined measurements of the EAS-TOP air shower array (2005 m a.s.l., 10**5 m**2 collecting area) and the MACRO underground detector (963 m a.s.l., 3100 m w.e. of minimum rock overburden, 920 m**2 effective area) at the National Gran Sasso Laboratories. The used observables are the air shower size (Ne) measured by EAS-TOP and the muon number (Nmu) recorded by MACRO. The two detectors are separated on average by 1200 m of rock, and located at a respective zenith angle of about 30 degrees. The energy threshold at the surface for muons reaching the MACRO depth is approximately 1.3 TeV. Such muons are produced in the early stages of the shower development and in a kinematic region quite different from the one relevant for the usual Nmu-Ne studies. The measurement leads to a primary composition becoming heavier at the knee of the primary spectrum, the knee itself resulting from the steepening of the spectrum of a primary light component (p, He). The result confirms the ones reported from the observation of the low energy muons at the surface (typically in the GeV energy range), showing that the conclusions do not depend on the production region kinematics. Thus, the hadronic interaction model used (CORSIKA/QGSJET) provides consistent composition results from data related to secondaries produced in a rapidity region exceeding the central one. Such an evolution of the composition in the knee region supports the "standard" galactic acceleration/propagation models that imply rigidity dependent breaks of the different components, and therefore breaks occurring at lower energies in the spectra of the light nuclei.Comment: Submitted to Astroparticle Physic

UN GENERATORE DI PETTINE DI FREQUENZE PER L’ECCITAZIONE DI RIVELATORI DI FOTONI A BASSA ENERGIA

Il lavoro qui presentato, che nasce dalla collaborazione tra l’LNTS (Laboratorio Nuove Tecnologie e Strumenti) dell’INGV e il Dipartimento di Fisica dell’Università di Roma “La Sapienza”, descrive lo strumento realizzato per fornire il pettine di frequenze atto ad eccitare un sistema sperimentale per otto risuonatori KID. In tale sistema il pettine di frequenze verrà traslato nella banda di frequenza dei KIDs (nell’ordine dei GHz) per poterne effettuare l’eccitazione e quindi riportato nella banda iniziale per effettuarne l’acquisizione e l’analisi.INGV, Università La SapienzaPublished1.10. TTC - Telerilevamentoope

The Lusi drone: A multidisciplinary tool to access extreme environments

Extreme and inaccessible environments are a new frontier that unmanned and remotely operated ve-hicles can today safely access and monitor. The Lusi mud eruption (NE Java Island, Indonesia) representsone of these harsh environments that are totally unreachable with traditional techniques. Here boilingmud is constantly spewed tens of meters in height and tall gas clouds surround the 100 m wide activecrater. The crater is surrounded by a ~600 m diameter circular zone of hot mud that prevents anyapproach to investigate and sample the eruption site. In order to access this active crater we designedand assembled a multipurpose drone.The Lusi drone is equipped with numerous airborne devices suitable for use on board of other mul-ticopters. During the missions, three cameras can complete 1) video survey, 2) high resolution photo-grammetry of desired and preselected polygons, and 3) thermal photogrammetry surveys with infra-redcamera to locate hotfluids seepage areas or faulted zones. Crater sampling and monitoring operationscan be pre-planned with aflight software, and the pilot is required only for take-off and landing. A winchallows the deployment of gas, mud and water samplers and contact thermometers to be operated withno risk for the aircraft. During the winch operations (that can be performed automatically), the aircrafthovers at a safety height until the tasks controlled by the winch-embedded processor are completed. Thedrone is also equipped with GPS-connected CO2and CH4sensors. Gridded surveys using these devicesallowed obtaining 2D maps of the concentration and distribution of various gasses over the area coveredby theflight path.The device is solid, stable even with significant wind, affordable, and easy to transport. The Lusi dronesuccessfully operated during several expeditions at the ongoing active Lusi eruption site and proved to bean excellent tool to study other harsh or unreachable sites, where operations with more conventionalmethods are too expensive, dangerous or simply impossibleLUSI LAB project, PI A. Mazzini; esearch Council of Norway through itsCenters of Excellence funding scheme, Project Number 223272; BPLS (Badan Penanggulangan Lumpur Sidoarjo, Sidoarjo Mudflow Management Agency)Published26-372IT. Laboratori sperimentali e analiticiJCR Journa

Volcanic edifice weakening via devolatilization reactions

International audienceEdifice instability, that can result in catastrophic flank collapse, is a fundamental volcanic hazard. The subvolcanic basement can encourage such instability, especially if it is susceptible to mechanical weakening by devolatilization reactions near magmatic temperatures. For this reason, understanding how the physical and chemical properties of representative lithologies deteriorate at high temperatures is potentially highly relevant for volcanic hazard mitigation. This is particularly true for sedimentary rock, commonly found underlying volcanic edifices worldwide, that undergo rapid deterioration even under modest temperatures. Therefore, here we present the first experimental study of devolatilization reactions, induced by magmatic temperatures, on sedimentary rock comprising a subvolcanic basement. Our results show that, for a marly limestone representative of the basement at Mt Etna, devolatilization reactions, namely the dehydroxylation of clay minerals and the decarbonation of calcium carbonate, result in a dramatic reduction of mechanical strength and seismic velocities. These temperature-driven reactions can promote volcanic instability at stresses much lower than previously estimated