Search results for "XENON"
showing 10 items of 172 documents
Energy calibration of the NEXT-White detector with 1% resolution near Q ββ of 136Xe
2019
Excellent energy resolution is one of the primary advantages of electroluminescent high pressure xenon TPCs, and searches for rare physics events such as neutrinoless double-beta decay ($\beta\beta0\nu$) require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for $\beta\beta0\nu$ searches.
Mitigation of backgrounds from cosmogenic 137 Xe in xenon gas experiments using 3 He neutron capture
2020
[EN] Xe-136 is used as the target medium for many experiments searching for 0 nu beta beta. Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of Xe-137 created by the capture of neutrons on Xe-136. This isotope decays via beta decay with a half-life of 3.8 min and a Q(beta) of similar to 4.16 MeV. This work proposes and explores the concept of adding a small percentage of He-3 to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we f…
Magnetic resonance imaging of dissolved hyperpolarized 129Xe using a membrane-based continuous flow system.
2009
Abstract A technique for continuous production of solutions containing hyperpolarized 129Xe is explored for MRI applications. The method is based on hollow fiber membranes which inhibit the formation of foams and bubbles. A systematic analysis of various carrier agents for hyperpolarized 129Xe has been carried out, which are applicable as contrast agents for in vivo MRI. The image quality of different hyperpolarized Xe solutions is compared and MRI results obtained in a clinical as well as in a nonclinical MRI setting are provided. Moreover, we demonstrate the application of 129Xe contrast agents produced with our dissolution method for lung MRI by imaging hyperpolarized 129Xe that has been…
Sensitivity of a tonne-scale NEXT detector for neutrinoless double-beta decay searches
2021
The NEXT collaboration: et al.
Developments for neutron-induced fission at IGISOL-4
2016
At the IGISOL-4 facility, neutron-rich, medium mass nuclei have usually been produced via charged particle-induced fission of natural uranium and thorium. Neutron-induced fission is expected to have a higher production cross section of the most neutron-rich species. Development of a neutron source along with a new ion guide continues to be one of the major goals since the commissioning of IGISOL-4. Neutron intensities at di↵erent angles from a beryllium neutron source have been measured in an on-line experiment with a 30 MeV proton beam. Recently, the new ion guide coupled to the neutron source has been tested as well. Details of the neutron source and ion guide design together with prelimi…
Search for very long-lived isomers in the hafnium-tungsten region
2000
Targets of ${}^{48}\mathrm{Ca}$ have been bombarded with ${}^{134,136}\mathrm{Xe}$ beams as part of a search for long-lived, high-K states in well-deformed nuclei with $A\ensuremath{\approx}180.$ Several known isomers were observed by off-line \ensuremath{\gamma}-ray detection, and limits have been established for high-K isomer production in various isotopes of hafnium $(A=175--178),$ tantalum $(A=177--181),$ and tungsten $(A=177--181).$
Ultra-high resolution mass separator—Application to detection of nuclear weapons tests
2009
Abstract A Penning trap-based purification process having a resolution of about 1 ppm is reported. In this context, we present for the first time a production method for the most complicated and crucially important nuclear weapons test signature, 133mXe. These pure xenon samples are required by the Comprehensive Nuclear-Test-Ban Treaty Organization to standardize and calibrate the worldwide network of xenon detectors.
In-beam study of the 128, 130Xe nuclei
1981
Abstract The level structure of 128,130Xe has been studied in the (α, 2nγ) and (3He, 3nγ) reactions on enriched Te targets using in-beam γ-ray spectroscopic methods. For both nuclei the existing information about positive-parity level structure was enriched and many new negative-parity two-quasiparticle states were observed. Isomeric states with the half-lives of 63 ± 12 ns in 128 Xe and 4.8 ± 0.5 ns in 130 Xe were found. For collective positive-parity states the interacting boson model, and calculations based on Bohr hamiltonian were compared with the experimental data.
MRI of the lungs using hyperpolarized noble gases
2002
The nuclear spin polarization of the noble gas isotopes (3)He and (129)Xe can be increased using optical pumping methods by four to five orders of magnitude. This extraordinary gain in polarization translates directly into a gain in signal strength for MRI. The new technology of hyperpolarized (HP) gas MRI holds enormous potential for enhancing sensitivity and contrast in pulmonary imaging. This review outlines the physics underlying the optical pumping process, imaging strategies coping with the nonequilibrium polarization, and effects of the alveolar microstructure on relaxation and diffusion of the noble gases. It presents recent progress in HP gas MRI and applications ranging from MR mi…
Photoprotection and photoreception of intraocular lenses under xenon and white LED illumination.
2016
Objective. To analyze the photoprotection and phototransmission that various intraocular lenses (10Ls) provide under the illumination of a xenon (Xe) lamp and white LEDs (light emitting diode). Methods. The spectral transmission curves of six representative 10Ls were measured using a Perkin-Elmer Lambda 35 UV/VIS spectrometer. Various filtering simulations were performed using a Xe lamp and white LEDs. The spectral emissions of these lamps were measured with an ILT-950 spectroradiometer. Results. The 10Ls analyzed primarily show transmission of nearly 100% in the visible spectrum. In the ultraviolet (UV) region, the filters incorporated in the various 10Ls did not filter equally, and some o…