Progress in mass measurements of stored exotic nuclei at relativistic energies

Citation
H. Geissel et al., Progress in mass measurements of stored exotic nuclei at relativistic energies, NUCL PHYS A, 685, 2001, pp. 115C-126C
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
NUCLEAR PHYSICS A
ISSN journal
0375-9474 → ACNP
Volume
685
Year of publication
2001
Pages
115C - 126C
Database
ISI
SICI code
0375-9474(20010326)685:<115C:PIMMOS>2.0.ZU;2-3
Abstract
Exotic nuclei produced via projectile fragmentation were separated in fligh t by the fragment separator FRS and injected into the storage ring ESR at ( 300-400) MeV/u. Ultra-cold fragment beams with half-lives larger than 10 s were investigated by Schottky Mass Spectroscopy (SMS) applying electron coo ling. A new efficient data acquisition system recorded the time correlation s allowing corrections for possible drifts of the revolution frequencies. I n addition, it allows to observe the nuclear decay of the fragments circula ting in the ESR. Representative results of previously unknown masses of abo ut 150 neutron-deficient isotopes in the range of 52 less than or equal to Z less than or equal to 85 are discussed. Results for lead isotopes are com pared with different mass models. Exotic nuclei with half-lives shorter tha n the time required for electron cooling have been investigated by time-of- flight measurements with the ESR being operated in the isochronous mode. Th is novel experimental technique gives access to all nuclei with half-lives down to the microsecond range and has been successfully applied in first ex periments with light fragments produced by Cr-52 and Kr-84 projectiles. A m ass resolving power of better than m/Deltam = 0.9 . 10(5) (FWHM) was achiev ed with isochronous mass spectrometry (IMS).