Search results for "γ-ray"
showing 8 items of 18 documents
In-beam spectroscopic studies of shape coexistence and collectivity in the neutron-deficientZ≈ 82 nuclei
2016
In the present paper we focus on studies of shape coexistence in even-mass nuclei in the neutron-deficient Pb region. They are based on experiments carried out using tagging techniques in the Accelerator Laboratory of the University of Jyväskylä, Finland. Excited states in many of these nuclei can only be accessed via fusion-evaporation reactions employing high-intensity stable-ion beams. The key features in these experiments are high selectivity, clean spectra and instrumentation that enables high count rates. We review three spectroscopic highlights in this region. peerReviewed
High-spin states in the neutron-rich A∼100 region
2009
Two experimental setups have been used to study excited states of neutron‐rich nuclei in the A∼100 region. Extended level schemes and lifetime measurements were obtained using deep‐inelastic and fusion‐fission reactions with the CLARA‐PRISMA spectrometer and the Ge‐array GASP respectively. Experimental information from GASP has been used to complement the CLARA‐PRISMA experiment. Time spectra have been used to measure the lifetimes of isomeric states. Preliminary results are presented for 89Rb.
First experiment with the NUSTAR/FAIR Decay Total Absorption γ-Ray Spectrometer (DTAS) at the IGISOL IV facility
2015
V. Guadilla et al. ; 4 págs.; 4 figs.; 1 tab.
Properties and morphology of PMMA/ABN blends obtained via MMA in situ polymerisation through γ-rays
2001
Abstract Methylmethacrylate polymerisation in the presence of 4 wt% butadiene-acrylonitrile rubber was carried out at fixed dose-rate and temperature. The effect of irradiation was investigated with respect to the mechanical and dynamic-mechanical properties in the solid state. A general increase of the “compatibilisation” on irradiation is obtained. In fact both rubber and polymethylmethacrylate glass transition temperatures, determined through dynamic-mechanical analysis, reveal the presence of strong interactions between the components. Furthermore an improvement of the mechanical tensile properties of the blends is observed when irradiation is continued after polymerisation, at least un…
Physics opportunities with the Advanced Gamma Tracking Array : AGATA
2020
New physics opportunities are opening up by the Advanced Gamma Tracking Array, AGATA, as it evolves to the full 4π instrument. AGATA is a high-resolution γ-ray spectrometer, solely built from highly segmented high-purity Ge detectors, capable of measuring γ rays from a few tens of keV to beyond 10 MeV, with unprecedented efficiency, excellent position resolution for individual γ-ray interactions, and very high count-rate capability. As a travelling detector AGATA will be employed at all major current and near-future European research facilities delivering stable and radioactive ion beams. peerReviewed
In-beam γ-ray spectroscopy of low- and medium-spin levels in 211Po
2017
The structure of the low- and medium-spin levels of the 211Po nucleus have been studied with in-beam γ-ray spectroscopy with the 208Pb(α,n)211Po fusion-evaporation reaction. The level scheme was further extended with levels of the configurations π(h9/2)22+−4+⊗νg9/2, π(h9/2)28+⊗νg9/2, π(h9/2)22+−4+⊗νi11/2, π(h9/2)22+−4+⊗νj15/2, π(h9/2f7/2)8+⊗νg9/2, and π(h9/2)20+⊗ν(g9/2)20+(s1/2)−1. The single-particle neutron states νd5/2 and νs1/2 were also identified. Furthermore, a number of states feeding the low-spin structures were added. peerReviewed
Spectroscopy of [sub 199,201]At
2015
The excited states of 199At and 201At were studied using fusion evaporation reactions, a gas-filled recoil separator and various tagging methods. The level scheme of 201At was extended a lot including a cascade of magnetic dipole transitions, that is suggested to form a shears band. In addition, a 29/2+ [T1/2 = 3.39(9) s] isomeric state was observed. The 29/2+ state is suggested to originate from the p(h9/2) j200Po; 11i configuration, and it depopulates through 269-keV E2 and 339-keV E3 transitions. In both nuclei 199,201At we have observed also the isomeric 1/2+ [T1/2 = 273(9), 45(3) ms, respectively] intruder state, that is suggested to originate from the p(s1/2)1 configuration. The 1…
The Large Observatory For x-ray Timing
2014
The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideFi…