학술논문
Coulomb excitation of radioactive 20, 21.sup.Na
Document Type
Report
Author
Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.
Source
The European Physical Journal A - Hadrons and Nuclei. Dec, 2009, Vol. 42 Issue 3, p477, 8 p.
Subject
Language
English
ISSN
1434-6001
Abstract
The low-energy structures of the radioactive nuclei 20, 21.sup.Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of [proportional to] 5x10.sup.6 ions/s were accelerated to 1.7MeV/A and Coulomb excited in a 0.5mg/cm^2 nat.sup.Ti target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for [gamma] -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For 21.sup.Na , Coulomb excitation from the 3/2.sup.+ ground state to the first excited 5/2.sup.+ state was observed, while for 20.sup.Na , Coulomb excitation was observed from the 2.sup.+ ground state to the first excited 3.sup.+ and 4.sup.+ states. For both beams, B ( [lambda] L) values were determined using the 2.sup.+ [right arrow] 0.sup.+ de-excitation in 48.sup.Ti as a reference. The resulting B(E2) [right arrow] value for 21.sup.Na is 137+-9 e^2fm^4, while the resulting B( [lambda] L) [right arrow] values for 20.sup.Na are 55+-6 e^2fm^4 for the 3.sup.+ [right arrow] 2.sup.+ , 35.7+-5.7 e^2 fm^4 for the 4.sup.+ [right arrow] 2.sup.+ , and 0.154+-0.030 u_N^2 for the 4.sup.+ [right arrow] 3.sup.+ transitions. This analysis significantly improves the measurement of the 21.sup.Na B(E2) value, and provides the first experimental determination of B( [lambda] L) values for the proton dripline nucleus 20.sup.Na .-1