Engineering Papers⌕ Search

Engineering topics

Franco, D.

Publications and source records attributed to Franco, D..

113 records · Page 7

Ortho-positronium observation in the Double Chooz experiment

The Double Chooz experiment measures the neutrino mixing angle θ13 by detecting reactor ν¯e via inverse beta decay. The positron-neutron space and time coincidence allows for a sizable background rejection, nonetheless liquid scintillator detectors would

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Improved measurements of the neutrino mixing angle θ 13 with the Double Chooz detector

The Double Chooz experiment presents improved measurements of the neutrino mixing angle θ13 using the data collected in 467.90 live days from a detector positioned at an average distance of 1050 m from two reactor cores at the Chooz nuclear power plant. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties with respect to previous publications, whereas the efficiency of the ν¯e signal has increased. The value of θ13 is measured to be sin22θ13=0.090+0.032-0.029 from a fit to the observed energy spectrum. Deviations from the reactor ν¯e prediction observed above a prompt signal energy of 4 MeV and possible explanations are also reported. A consistent value of θ13 is obtained from a fit to the observed rate as a function of the reactor power independently of the spectrum shape and background estimation, demonstrating the robustness of the θ13 measurement despite the observed distortion.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Improved measurement of the 2 ν β β half-life of 136 Xe with the EXO-200 detector

In this work, we report on an improved measurement of the 2 ν β β half-life of 136 Xe performed by EXO-200. The use of a large and homogeneous time-projection chamber allows for the precise estimate of the fiducial mass used for the measurement, resulting in a small systematic uncertainty. We also discuss in detail the data-analysis methods used for double- β decay searches with EXO-200, while emphasizing those directly related to the present measurement. The 136 Xe 2 ν β β half-life is found to be T 1 / 2 2 ν β β = 2.165 ± 0.016 ( stat ) ± 0.059 ( sys ) × 10 21 yr. Finally, this is the most precisely measured half-life of any 2 ν β β decay to date.

136Xe↗

DarkSide search for dark matter

The DarkSide staged program utilizes a two-phase time projection chamber (TPC) with liquid argon as the target material for the scattering of dark matter particles. Efficient background reduction is achieved using low radioactivity underground argon as well as several experimental handles such as pulse shape, ratio of ionization over scintillation signal, 3D event reconstruction, and active neutron and muon vetos. The DarkSide-10 prototype detector has proven high scintillation light yield, which is a particularly important parameter as it sets the energy threshold for the pulse shape discrimination technique. The DarkSide-50 detector system, currently in commissioning phase at the Gran Sasso Underground Laboratory, will reach a sensitivity to dark matter spin-independent scattering cross section of 10 -45 cm 2 within 3 years of operation.

79 ASTRONOMY AND ASTROPHYSICS↗