Analysis of ground-based Rn-222 measurements over Spain: filling the gap in southwestern Europe

Harmonized atmospheric 222Rn observations are required by the scientific community: these data have been lacking in southern Europe. We report on three recently established ground-based atmospheric 222Rn monitoring stations in Spain. We characterize the variability of atmospheric 222Rn concentrations at each of these stations in relation to source strengths, local, and regional atmospheric processes. For the study, measured atmospheric 222Rn concentrations, estimated 222Rn fluxes, and regional footprint analysis have been used. In addition, the atmospheric radon monitor operating at each station has been compared to a 222Rn progeny monitor. Annual means of 222Rn concentrations at Gredos (GIC3), Delta de l'Ebre (DEC3), and Huelva (UHU) stations were 17.3¿±¿2.0¿Bq¿m-3, 5.8¿±¿0.8¿Bq¿m-3, and 5.1¿±¿0.7¿Bq¿m-3, respectively. The GIC3 station showed high 222Rn concentration differences during the day and by seasons. The coastal station DEC3 presented background concentrations typical of the region, except when inland 222Rn-rich air masses are transported into the deltaic area. The highest 222Rn concentrations at UHU station were observed when local recirculation facilitates accumulation of 222Rn from nearby source represented by phosphogypsum piles. Results of the comparison performed between monitors revealed that the performance of the direct radon monitor is not affected by meteorological conditions, whereas the 222Rn progeny monitor seems to underestimate 222Rn concentrations under saturated atmospheric conditions. Initial findings indicate that the monitor responses seem to be in agreement for unsaturated atmospheric conditions but a further long-term comparison study will be needed to confirm this result.Peer ReviewedPostprint (published version

A first update on mapping the human genetic architecture of COVID-19

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Variabilidad espacial y temporal de fuentes y concentraciones de radón en la baja atmósfera

En este trabajo se ha estudiado el comportamiento tanto de las fuentes de radón como el de su concentración en la baja atmósfera en Andalucía, se ha caracterizado la dependencia de ambos con las condiciones meteorológicas locales y, de esta forma, se ha evaluado el efecto de fuentes antropogénicas tales como las balsas de fosfoyeso de Huelva sobre la concentración local de radón superficial en la ciudad y poblaciones cercanas del Sur de la Península Ibérica. Se ha establecido un inventario de emisiones de radón a la atmósfera, a escala europea, con alta resolución espacial y dependiente de las variables meteorológicas. Además, se ha elaborado una climatología de 40 años y se han obtenido las fluctuaciones estacionales y los ciclos de exhalación anuales para Europa. Se han calculado los valores típicos de concentración de radónen diferentes localizaciones del sur de la península ibérica. Además, se ha evaluado la influencia de las balsas de fosfoyeso sobre la concentración de radón de Huelva y se ha estimado la contribución a la tasa de dosis efectiva media debida a la inhalación de radón en exteriores de esta fuente antropogénica.The main aims of this work have been addressed to the study of the behaviour of both radon concentrations and radon sources in the low atmosphere of Andalusia, characterizing their dependence with local meteorological conditions. In this way, it could be possible evaluating the effect of anthropogenic radon sources such as the phosphogypsum (PG) stacks of Huelva (Mendana salt-marshes land, near Huelva town) on local radon concentration at the city and close locations at the South of Iberian peninsula. A high resolution European-scale inventory of radon emissions to the atmosphere has been established. Furthermore, a 40 years-scale climatologic description of radon, season scale fluctuations and annual radon exhalation cycles have been obtained. TTypical values of radon concentration in air and its dynamics of change at different locations in the South of Iberian Peninsula have been calculated. The influence of the PG stacks on radon concentration in air and its dosimetric contribution have been also determined. The application of computer simulation to this problem has allowed determining the effect of such source in Huelva town and the SW of the Iberian Peninsula for several especially relevant episodes

High-purity materials Production and application

The paper gives data on the properties of a number of high-purity materials whose development was supported by the Federal Scientific and Technical Program The Advanced Materials, among them polycrystalline zinc selenide for optics with an absorption coefficient of (5-10) x 10"-"4 cm"-"3 at the wavelength of 10.6 #mu#m. Glasses for fiber light guides based on arsenic sulphide and selenide exhibit the heterophase submicron inclusion content #<=#2 x 10"4 cm"3 and the oxygen, carbon and hydrogen impurity content of 10"-"4 - 10"-"6 at%. We have prepared seven standard samples of rare-earth and high-melting metals, whose impurity contents range from 10"-"3 to 10"-"9 wt%. The promising directions in the further development of narrow-gap semiconductors and high-purity optical materials are indicated. (author)Translated from Russian (Advanced Materials '99 Conference Proceedings, Inst. of Strength of Materials, Kiev, 1999)Available from British Library Document Supply Centre-DSC:9023.190(9654)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Studying radon exhalation rates variability from phosphogypsum piles in the SW of Spain

Nearly 1.0×108 tonnes of phosphogypsum were accumulated during last 50 years on a 1200ha disposal site near Huelva town (SW of Spain). Previous measurements of exhalation rates offered very variable values, in such a way that a worst case scenario could not be established. Here, new experimental data coupled to numerical simulations show that increasing the moisture contents or the temperature reduces the exhalation rate whilst increasing the radon potential or porosity has the contrary effect. Once the relative effects are compared, it can be drawn that the most relevant parameters controlling the exhalation rate are radon potential (product of emanation factor by 226Ra concentration) and moisture saturation of PG. From wastes management point of view, it can be concluded that piling up the waste increasing the height instead of the surface allows the reduction of the exhalation rate. Furthermore, a proposed cover here is expected to allow exhalation rates reductions up to 95%. We established that the worst case scenario corresponds to a situation of extremely dry winter. Under these conditions, the radon exhalation rate (0.508Bqm-2s-1) would be below though close to the upper limit established by U.S.E.P.A. for inactive phopsphogypsum piles (0.722Bqm-2s-1)

Observations of the magnetars 4U 0142+61 and 1E 2259+586 with the MAGIC telescopes (Research Note)

Context. Magnetars are an extreme, highly magnetized class of isolated neutron stars whose large X-ray luminosity is believed to be driven by their high magnetic field. Aims. We study for the first time the possible very high energy gamma-ray emission above 100 GeV from magnetars, observing the sources 4U 0142+ 61 and 1E 2259+586. Methods. We observed the two sources with atmospheric Cherenkov telescopes in the very high energy range (E > 100 GeV). 4U0142+61 was observed with the MAGIC I telescope in 2008 for about 25 h and 1E 2259+586 was observed with the MAGIC stereoscopic system in 2010 for about 14 h. The data were analyzed with the standard MAGIC analysis software. Results. Neither magnetar was detected. Upper limits to the differential and integral flux above 200 GeV were computed using the Rolke algorithm. We obtain integral upper limits to the flux of 1.52 x 10(-12) cm(-2) s(-1) and 2.7 x 10(-12) cm(-2) s(-1) with a confidence level of 95% for 4U 0142+ 61 and 1E 2259+586, respectively. The resulting differential upper limits are presented together with X-ray data and upper limits in the GeV energy range

Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

Cosmological and astrophysical observations suggest that 85\% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy $\gamma$ rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment's individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different $\gamma$-ray instruments

CTA contributions to the 33rd International Cosmic Ray Conference (ICRC2013)

Compilation of CTA contributions to the proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), which took place in 2-9 July, 2013, in Rio de Janeiro, BrazilComment: Index of CTA conference proceedings at the ICRC2013, Rio de Janeiro (Brazil). v1: placeholder with no arXiv links yet, to be replaced once individual contributions have been all submitted. v2: final with arXiv links to all CTA contributions and full author lis