0000000000273722
AUTHOR
A. Shrivastava
First application of calorimetric low-temperature detectors in accelerator mass spectrometry
Abstract For the first time, calorimetric low-temperature detectors were applied in accelerator mass spectrometry, a well-known method for determination of very small isotope ratios with high sensitivity. The aim of the experiment was to determine with high accuracy the isotope ratio of 236U/238U for several samples of natural uranium, 236U being known as a sensitive monitor for neutron flux. Measurements were performed at the VERA tandem accelerator at Vienna, Austria. The detectors consist of sapphire absorbers and superconducting transition edge thermometers operated at T≈ 1.5 K. The relative energy resolution obtained for 17.39 MeV 238U is ΔE/E=4–9×10−3, depending on the experimental co…
New gas-filled mode of the large-acceptance spectrometer VAMOS
A new gas-filled operation mode of the large-acceptance spectrometer VAMOS at GANIL is reported. A beam rejection factor greater than 10(10) is obtained for the Ca-40+Sm-150 system at 196 MeV. The unprecedented transmission efficiency for the evaporation residues produced in this reaction is estimated to be around 80% for alpha x n channels and above 95% for x ny p channels. A detailed study of the performance of the gas-filled VAMOS and future developments are discussed. This new operation mode opens avenues to explore the potential of fusion reactions in various kinematics. (C) 2010 Elsevier B.V. All rights reserved.
Quasi-free scattering with 6,8He beams
Abstract This paper presents the results of experimental investigations of ( p , p n ) , ( p , p α ) and ( p , p 6 He) reactions with relativistic 6 He and 8 He beams impinging on a hydrogen target. Information on the structure of extremely neutron-rich nuclei was obtained by using the unique characteristic of quasi-free scattering processes and inverse kinematics. For the first time, momentum distributions of complex clusters inside 6 He and 8 He were measured. Spectroscopic factors for valence neutrons, α - and 6 He clusters were deduced from the experimental data. They demonstrate that the filling of the p 1 2 shell is the essential feature of the 8 He structure. It is shown that the 8 H…