77 research outputs found
Indirect study of 19Ne states near the 18F+p threshold
The early E < 511 keV gamma-ray emission from novae depends critically on the
18F(p,a)15O reaction. Unfortunately the reaction rate of the 18F(p,a)15O
reaction is still largely uncertain due to the unknown strengths of low-lying
proton resonances near the 18F+p threshold which play an important role in the
nova temperature regime. We report here our last results concerning the study
of the d(18F,p)19F(alpha)15N transfer reaction. We show in particular that
these two low-lying resonances cannot be neglected. These results are then used
to perform a careful study of the remaining uncertainties associated to the
18F(p,a)15O and 18F(p,g)19Ne reaction rates.Comment: 18 pages, 8 figures. Accepted in Nuclear Physics
D(18F,pa)15N reaction applied to nova gamma-ray emission
The 18F(p,alpha)15O reaction is recognized to be one of the most important
reactions for nova gamma-ray astronomy as it governs the early E <= 511keV
gamma emission. However in the nova temperature regime, its rate remains
largely uncertain due to unknown low-energy resonance strengths. We report here
the measurement of the D(18F,p)19F(alpha)15N one-nucleon transfer reaction,
induced by a 14 MeV 18F radioactive beam impinging on a CD2 target; outgoing
protons and 15N (or alpha-particles) were detected in coincidence in two
silicon strip detectors. A DWBA analysis of the data resulted in new limits to
the contribution of low-energy resonances to the rate of the 18F(p,alpha)15O
reaction.Comment: Rapid Communication to appear in Phys. Rev. C., 4 pages and 4 figure
The Acceleration and Storage of Radioactive Ions for a Beta-Beam Facility
The term beta-beam has been coined for the production of a pure beam of
electron neutrinos or their antiparticles through the decay of radioactive ions
circulating in a storage ring. This concept requires radioactive ions to be
accelerated to as high Lorentz gamma as 150. The neutrino source itself
consists of a storage ring for this energy range, with long straight sections
in line with the experiment(s). Such a decay ring does not exist at CERN today,
nor does a high-intensity proton source for the production of the radioactive
ions. Nevertheless, the existing CERN accelerator infrastructure could be used
as this would still represent an important saving for a beta-beam facility.Comment: beta-beam working group website at http://cern.ch/beta-bea
The SPIRAL radioactive ion beam facility
This document describes the scientific goals as well as the technical choices of the SPIRAL project (Système de Production d'Ions Radioactifs et d'Accélération en Ligne)
The MICE Collaboration
A Neutrino Factory based on a muon storage ring is the ultimate tool for studies of neutrino oscillations, including possibly the discovery of leptonic CP violation. It is also the first step towards a µ + µ – collider. Ionization cooling of muons has never been demonstrated in practise but has been shown by end-to-end simulation and design studies to be an important factor both for the performance and for the cost of a Neutrino Factory. This motivates an international programme of R&D, including an experimental demonstration. The aims of the international Muon Ionization Cooling Experiment proposed in this document are: • To show that it is possible to design, engineer and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory; • To place it in a muon beam and measure its performance in various modes of operation and beam conditions, thereby investigating the limits and practicality of cooling. The MICE collaboration have designed an experiment in which a section of an ionization cooling channel is exposed to a muon beam. This cooling channel assembles liquid-hydroge
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