J. Díaz

Anthropogenic heavy metal pollution in the sediments of the Barcelona continental shelf (Northwestern Mediterranean)

Abstract The surface sediments of the Barcelona continental shelf are greatly affected by anthropogenic contamination of heavy metals discharged by the littoral sewers and the Besos River. This pollution affects mainly the sediment of the inner Besos prodelta, decreasing gradually southward and more sharply seaward from the river and sewer mouths. In the outer part of the prodelta heavy metal pollution is relatively low, except in the area where the waste discharged through the pipeline of the Barcelona-Besos wastewater treatment plant accumulates. This waste produces a strong metal anomaly with a sharp bordering gradient. The relict sandy sediment of the outer part of the shelf is hardly affected by heavy metal pollution.

First proof of topological signature in high pressure xenon gas with electroluminescence amplification

A bstractThe NEXT experiment aims to observe the neutrinoless double beta decay of 136Xe in a high-pressure xenon gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qββ. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype.Single electrons resulting from the interactions of 22Na 1275 keV gammas and electronpositron pairs produced by conversions of gammas from the 228Th decay chain were used to represent the background and the signal in a double beta decay. These data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 ± 1.4 (stat.)%, while maintaining an efficiency of 66.7 ± 1.% for signal events.

Present Status and Future Perspectives of the NEXT Experiment

NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector is a TPC, holding 100 kg of high-pressure xenon enriched in the 136Xe isotope. It is under construction in the Laboratorio Subterraneo de Canfranc in Spain, and it will begin operations in 2015. The NEXT detector concept provides an energy resolutionbetter than 1% FWHM and a topological signal that can be used to reduce the background. Furthermore, the NEXT technology can be extrapolated to a 1 ton-scale experiment.

Characterisation of NEXT-DEMO using xenon Kα X-rays

The NEXT experiment aims to observe the neutrinoless double beta decay of

Use of frequency analysis on the ECG for the prognosis of low energy cardioversion treatment of atrial fibrillation

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Radon and material radiopurity assessment for the NEXT double beta decay experiment

Xe in a high pressure gas TPC using electroluminescence (EL) to amplify the signal from ionization. Understanding the response of the detector is imperative in achieving a consistent and well understood energy measurement. The abundance of xenon k-shell x-ray emission during data taking has been identified as a multitool for the characterisation of the fundamental parameters of the gas as well as the equalisation of the response of the detector. The NEXT-DEMO prototype is a ~1.5 kg volume TPC filled with natural xenon. It employs an array of 19 PMTs as an energy plane and of 256 SiPMs as a tracking plane with the TPC light tube and SiPM surfaces being coated with tetraphenyl butadiene (TPB) which acts as a wavelength shifter for the VUV scintillation light produced by xenon. This paper presents the measurement of the properties of the drift of electrons in the TPC, the effects of the EL production region, and the extraction of position dependent correction constants using K

Analysis of the space-time microstructure of cosmic ray air showers using the HADES RPC TOF wall

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Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

X-ray deposits. These constants were used to equalise the response of the detector to deposits left by gammas from

Characterisation of NEXT-DEMO using xenon K

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