Search results for "XENON"
showing 10 items of 172 documents
Present Status and Future Perspectives of the NEXT Experiment
2014
Gómez Cadenas, Juan José et al.
NEXT-100 Technical Design Report (TDR). Executive summary
2012
[EN] In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (ßß0v) in 136XE at the Laboratorio Subterráneo de Canfranc (LSC), in Spain. The document formalizes the design presented in our Conceptual Design Report (CDR): an electroluminescence time projection chamber, with separate readout planes for calorimetry and tracking, located, respectively, behind cathode and anode. The detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or 100 kg at 10 bar. This option builds in the capability to increase the total isotope mass by 50% while keeping the operating pressure at a manageable level. The readout pla…
Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment
2013
NEXT-DEMO is a large-scale prototype of the NEXT-100 detector, an electroluminescent time projection chamber that will search for the neutrinoless double beta decay of Xe-136 using 100-150 kg of enriched xenon gas. NEXT-DEMO was built to prove the expected performance of NEXT-100, namely, energy resolution better than 1% FWHM at 2.5MeV and event topological reconstruction. In this paper we describe the prototype and its initial results. A resolution of 1.75% FWHM at 511 keV (which extrapolates to 0.8% FWHM at 2.5 MeV) was obtained at 10 bar pressure using a gamma-ray calibration source. Also, a basic study of the event topology along the longitudinal coordinate is presented, proving that it…
Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements
2013
[EN] The "Neutrino Experiment with a Xenon Time-Projection Chamber" (NEXT) is intended to investigate the neutrinoless double beta decay of Xe-136, which requires a severe suppression of potential backgrounds. An extensive screening and material selection process is underway for NEXT since the control of the radiopurity levels of the materials to be used in the experimental set-up is a must for rare event searches. First measurements based on Glow Discharge Mass Spectrometry and gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterraneo de Canfranc (Spain) are described here. Activity results for natural radioactive chains and other common radionucl…
Imaging of a mixture of hyperpolarized 3He and 129Xe.
2004
Abstract With the use of hyperpolarized gases, a great number of experiments have been carried out in order to improve the diagnostics of the lung, both from a structural and a functional point of view. 3 He is best suited for structural studies, whereas 129 Xe gives more detailed information about the functionality of the lung because it enters the bloodstream. In this work, we propose the use of a gas mixture to perform consecutive analysis of lung structure and functionality upon the delivery of a single bolus of gas. We show images of a helium–xenon gas mixture in the presence of a small amount of liquid toluene in order to demonstrate how both nuclei can be detected independently, extr…
Using visual modelling to study the evolution of lizard coloration: sexual selection drives the evolution of sexual dichromatism in lacertids
2012
Sexual selection has been invoked as a major force in the evolution of secondary sexual traits, including sexually dimorphic colorations. For example, previous studies have shown that display complexity and elaborate ornamentation in lizards are associated with variables that reflect the intensity of intrasexual selection. However, these studies have relied on techniques of colour analysis based on human – rather than lizard – visual perception. Here, we use reflectance spectrophotometry and visual modelling to quantify sexual dichromatism considering the overall colour patterns of lacertids, a lizard clade in which visual signalling has traditionally been underrated. These objective method…
Xenon Improves Neurologic Outcome and Reduces Secondary Injury Following Trauma in an In Vivo Model of Traumatic Brain Injury*
2014
Objectives: To determine the neuroprotective efficacy of the inert gas xenon following traumatic brain injury and to determine whether application of xenon has a clinically relevant therapeutic time window. Design: Controlled animal study. Setting: University research laboratory. Subjects: Male C57BL/6N mice (n = 196). Interventions: Seventy-five percent xenon, 50% xenon, or 30% xenon, with 25% oxygen (balance nitrogen) treatment following mechanical brain lesion by controlled cortical impact. Measurements and Main Results: Outcome following trauma was measured using 1) functional neurologic outcome score, 2) histological measurement of contusion volume, and 3) analysis of locomotor functio…
Xenon improves long-term cognitive function, reduces neuronal loss and chronic neuroinflammation, and improves survival after traumatic brain injury …
2019
Background.Xenon is a noble gas with neuroprotective properties. We previously showed that xenon improves short and long-term outcomes in young adult mice after controlled cortical impact (CCI). This is a follow-up study investigating xenon’s effect on very long-term outcome and survival. Methods.C57BL/6N (n=72) young adult male mice received single CCI or sham surgery and were treated with either xenon (75%Xe:25%O2) or control gas (75% N2:25%O2). The outcomes used were: 1) 24-hour lesion volume and neurological outcome score; 2)contextual fear-conditioning at 2 weeks and 20 months; 3) corpus callosum white matter quantification; 4) immunohistological assessment of neuroinflammation and neu…
High Voltage Insulation and Gas Absorption of Polymers in High Pressure Argon and Xenon Gases
2018
High pressure gas time projection chambers (HPGTPCs) are made with a variety of materials, many of which have not been well characterized in high pressure noble gas environments. As HPGTPCs are scaled up in size toward ton-scale detectors, assemblies become larger and more complex, creating a need for detailed understanding of how structural supports and high voltage insulators behave. This includes the identification of materials with predictable mechanical properties and without surface charge accumulation that may lead to field deformation or sparking. This paper explores the mechanical and electrical effects of high pressure gas environments on insulating polymers PTFE, HDPE, PEEK, POM …
A New Sensitive Technique for Laser Spectroscopic Studies of Radioactive Rare-Gas Isotopes
1987
The concept of laser ionization has been widely used in spectroscopy studies and for the detection of minute samples of atoms. Being based on ion counting, it avoids the sensitivity problems of conventional fluorescence spectroscopy, which are due to low detection efficiency and large background from scattered laser light. We report the first application of an alternative ionization scheme which we have developed for collinear laser spectroscopy on fast atomic beams /1/. Here the increase in sensitivity has considerably enlarged the range of isotopes very far from stability, for which nuclear moments and radii can be investigated in hyperfine structure and isotope shift measurements.