Neutron background at the Canfranc Underground Laboratory and its contribution to the IGEX-DM dark matter experiment

A quantitative study of the neutron environment in the Canfranc Underground Laboratory has been performed. The analysis is based on a complete set of simulations and, particularly, it is focused on the IGEX-DM dark matter experiment. The simulations are compared to the IGEX-DM low energy data obtained with different shielding conditions. The results of the study allow us to conclude, with respect to the IGEX-DM background, that the main neutron population, coming from radioactivity from the surrounding rock, is practically eliminated after the implementation of a suitable neutron shielding. The remaining neutron background (muon-induced neutrons in the shielding and in the rock) is substantially below the present background level thanks to the muon veto system. In addition, the present analysis gives us a further insight on the effect of neutrons in other current and future experiments at the Canfranc Underground Laboratory. The comparison of simulations with the body of data available has allowed to set the flux of neutrons from radioactivity of the Canfranc rock, (3.82 +- 0.44) x 10^{-6} cm^{-2} s^{-1}, as well as the flux of muon-induced neutrons in the rock, (1.73 +- 0.22(stat) \+- 0.69(syst)) x 10^{-9} cm^{-2} s^{-1}, or the rate of neutron production by muons in the lead shielding, (4.8 +- 0.6 (stat) +- 1.9 (syst)) x 10^{-9} cm^{-3} s^{-1}.Comment: 17 pages, 8 figures, elsart document class; final version to appear in Astroparticle Physic

Calendar 2012

Background Fusarium species are among the most common fungi present in the environment and some species have emerged as major opportunistic fungal infection in human. However, in immunocompromised hosts they can be virulent pathogens and can cause death. The pathogenesis of this infection relies on three factors: colonization, tissue damage, and immunosuppression. A novel Fusarium species is reported for the first time from keratitis in an agriculture worker who acquired the infection from plant material of maize. Maize plants are the natural host of this fungus where it causes stalk rot and seeding malformation under temperate and humid climatic conditions. The clinical manifestation, microbiological morphology, physiological features and molecular data are described.MethodsDiagnosis was established by using polymerase chain reaction of fungal DNA followed by sequencing portions of translation elongation factor 1 alpha (TEF1 ¿) and beta-tubulin (BT2) genes. Susceptibility profiles of this fungus were evaluated using CLSI broth microdilution method.ResultsThe analyses of these two genes sequences support a novel opportunist with the designation Fusarium temperatum. Phylogenetic analyses showed that the reported clinical isolate was nested within the Fusarium fujikuroi species complex. Antifungal susceptibility testing demonstrated that the fungus had low MICs of micafungin (0.031 ¿g/ml), posaconazole (0.25 ¿g/ml) and amphotericin B (0.5 ¿g/ml).ConclusionThe present case extends the significance of the genus Fusarium as agents of keratitis and underscores the utility of molecular verification of these emerging fungi in the human host

A tomographic microscopy-compatible Langendorff system for the dynamic structural characterization of the cardiac cycle

ntroduction: Cardiac architecture has been extensively investigated ex vivo using a broad spectrum of imaging techniques. Nevertheless, the heart is a dynamic system and the structural mechanisms governing the cardiac cycle can only be unveiled when investigating it as such. Methods: This work presents the customization of an isolated, perfused heart system compatible with synchrotron-based X-ray phase contrast imaging (X-PCI). Results: Thanks to the capabilities of the developed setup, it was possible to visualize a beating isolated, perfused rat heart for the very first time in 4D at an unprecedented 2.75 μm pixel size (10.6 μm spatial resolution), and 1 ms temporal resolution. Discussion: The customized setup allows high-spatial resolution studies of heart architecture along the cardiac cycle and has thus the potential to serve as a tool for the characterization of the structural dynamics of the heart, including the effects of drugs and other substances able to modify the cardiac cycle

Status of IGEX dark matter search at Canfranc Underground Laboratory

One IGEX 76Ge double-beta decay detector is currently operating in the Canfranc Underground Laboratory in a search for dark matter WIMPs, through the Ge nuclear recoil produced by the WIMP elastic scattering. In this talk we report on the on-going efforts to understand and eventually reject the background at low energy. These efforts have led to the improvement of the neutron shielding and to partial reduction of the background, but still the remaining events are not totally identified. A tritium contamination or muon-induced neutrons are considered as possible sources, simulations and experimental test being still under progress. According to the success of this study we comment the prospects of the experiment as well as those of its future extension, the GEDEON dark matter experiment.Comment: 6 pages, 3 figures, talk given at 4th International Workshop on the Identification of Dark Matter, York, September 200

Near-infrared interferometric observation of the Herbig Ae star HD144432 with VLTI/AMBER

We study the sub-AU-scale circumstellar environment of the Herbig Ae star HD144432 with near-infrared (NIR) VLTI/AMBER observations to investigate the structure of its inner dust disk. The interferometric observations were carried out with the AMBER instrument in the H and K band. We interpret the measured H- and K-band visibilities, the near- and mid-infrared visibilities from the literature, and the SED of HD144432 by using geometric ring models and ring-shaped temperature-gradient disk models with power-law temperature distributions. We derived a K-band ring-fit radius of 0.17 \pm 0.01 AU and an H-band radius of 0.18 \pm 0.01 AU (for a distance of 145 pc). This measured K-band radius of \sim0.17 AU lies in the range between the dust sublimation radius of \sim0.13 AU (predicted for a dust sublimation temperature of 1500 K and gray dust) and the prediction of models including backwarming (\sim0.27 AU). We found that an additional extended halo component is required in both the geometric and temperature-gradient modeling. In the best temperature- gradient model, the disk consists of two components. The inner part of the disk is a thin ring with an inner radius of \sim0.21 AU, a temperature of \sim1600 K, and a ring thickness \sim0.02 AU. The outer part extends from \sim1 AU to \sim10 AU with an inner temperature of \sim400 K. We find that the disk is nearly face-on with an inclination angle of < 28 degree. Our temperature-gradient modeling suggests that the NIR excess is dominated by emission from a narrow, bright rim located at the dust sublimation radius, while an extended halo component contributes \sim6% to the total flux at 2 {\mu}m. The MIR model emission has a two-component structure with \sim20% flux from the inner ring and the rest from the outer part. This two-component structure suggests a disk gap, which is possibly caused by the shadow of a puffed-up inner rim.Comment: 7 pages, 5 figures, accepted by A&

RITA: a 1U multi-sensor Earth observation payload for the AlainSat-1

The Remote sensing and Interference detector with radiomeTry and vegetation Analysis (RITA) is one of the Remote Sensing payloads selected as winners of the 2nd GRSS Student Grand Challenge in 2019, to fly on board of the 3U AlainSat-1. This CubeSat is being developed by the National Space Science and Technology Center (NSSTC), United Arab Emirates University. RITA has been designed as an academic mission, which brings together students from different backgrounds in a joint effort to apply very distinct sensors in an Earth Observation mission, fusing their results to obtain higher-accuracy measurements. The main payload used in RITA is a Total Power Radiometer such as the one on board the FSSCat mission. With these radiometric measurements, soil moisture and ice thickness will be obtained. To better characterize the extensive Radio-Frequency Interferences received by EO satellites in protected bands, several RFI Detection and Classification algorithms will be included to generate a worldwide map of RFI. As a novel addition to the 3Cat family of satellites and payloads, a hyper-spectral camera with 25 bands ranging from 600 to 975 nm will be used to obtain several indexes related to vegetation. By linking these measurements with the soil moisture obtained from the MWR, pixel downscaling can be attempted. Finally, a custom- developed LoRa transceiver will be included to provide a multi-level approach to in-situ sensors: On-demand executions of the other payloads will be able to be triggered from ground sensors if necessary, as well as simple reception of other measurements that will complement the ones obtained on the satellite. The antennas for both the MWR and the LoRa experiments have been developed in-house, and will span the entirety of one of the 3U sides of the satellite. In this work, the latest development advances will be presented, together with an updated system overview and information about the operations that will be conducted. Results obtained from the test campaign are also presented in the conference

Twin digital short period seismic Array Experiment at Stromboli Volcano

Two small arrays composed by short period (1 Hz) digital seismic stations, with an aperture of approximately 400 meters, were set up at Stromboli volcano (one at semaforo Labronzo, the other at Ginostra- Timpone del Fuoco) with the purpose of the spatial location of the high frequency source of the explosion quakes. About 75 explosion-quakes were recorded at both arrays, and constitute the available data base. We have planned to apply the zero-lag cross-correlation technique to the whole data set in order to obtain back-azimuth and apparent slowness of the coherent seismic phases. A preliminary analysis for both arrays show that the predominant back-azimuth for the first phase is oriented in the direction of , but not strictly coincident to, the crater area. Moreover some back-scattered arrivals are quite evident in the seismogram.INGV - Osservatorio VesuvianoUnpublishedope

Towards a new generation axion helioscope

We study the feasibility of a new generation axion helioscope, the most ambitious and promising detector of solar axions to date. We show that large improvements in magnetic field volume, x-ray focusing optics and detector backgrounds are possible beyond those achieved in the CERN Axion Solar Telescope (CAST). For hadronic models, a sensitivity to the axion-photon coupling of \gagamma\gtrsim {\rm few} \times 10^{-12} GeV$^{-1}$ is conceivable, 1--1.5 orders of magnitude beyond the CAST sensitivity. If axions also couple to electrons, the Sun produces a larger flux for the same value of the Peccei-Quinn scale, allowing one to probe a broader class of models. Except for the axion dark matter searches, this experiment will be the most sensitive axion search ever, reaching or surpassing the stringent bounds from SN1987A and possibly testing the axion interpretation of anomalous white-dwarf cooling that predicts $m_a$ of a few meV. Beyond axions, this new instrument will probe entirely unexplored ranges of parameters for a large variety of axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics.Comment: 37 pages, 11 figures, accepted for publication in JCA