Issue Eur. Phys. J. A Volume 42, Number 3, December 2009 Topical Issue on ENAM'08 Page(s) 477 - 484 Section Regular Article - Experimental Physics DOI 10.1140/epja/i2009-10816-4

Eur. Phys. J. A 42, 477-484 (2009)
DOI: 10.1140/epja/i2009-10816-4

Coulomb excitation of radioactive ^{20, 21}Na

M. A. Schumaker¹, D. Cline², G. Hackman³, C. Pearson³, C. E. Svensson¹, C. Y. Wu⁴, A. Andreyev³, R. A. E. Austin⁵, G. C. Ball³, D. Bandyopadhyay¹, J. A. Becker⁴, A. J. Boston⁶, H. C. Boston⁶, L. Buchmann³, R. Churchman³, F. Cifarelli³, R. J. Cooper⁶, D. S. Cross⁷, D. Dashdorj⁸, G. A. Demand¹, M. R. Dimmock⁶, T. E. Drake⁹, P. Finlay¹, A. T. Gallant⁵, P. E. Garrett^{1, 3}, K. L. Green¹, A. N. Grint⁶, G. F. Grinyer¹, L. J. Harkness⁶, A. B. Hayes², R. Kanungo^{3, 5}, A. F. Lisetskiy¹⁰, K. G. Leach¹, G. Lee³, R. Maharaj³, J-P. Martin¹¹, F. Moisan¹², A. C. Morton³, S. Mythili^{3, 13}, L. Nelson⁶, O. Newman^{3, 14}, P. J. Nolan⁶, J. N. Orce^{3, 15}, E. Padilla-Rodal³, A. A. Phillips¹, M. Porter-Peden¹⁶, J. J. Ressler⁷, R. Roy¹², C. Ruiz³, F. Sarazin¹⁶, D. P. Scraggs⁶, J. C. Waddington¹⁷, J. M. Wan⁷, A. Whitbeck², S. J. Williams³ and J. Wong<sup>1

1</sup>  Department of Physics, University of Guelph, N1G 2W1, Guelph, Ontario, Canada
²  Department of Physics and Astronomy, University of Rochester, 14627, Rochester, NY, USA
³  TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
⁴  Lawrence Livermore National Laboratory, 94551, Livermore, CA, USA
⁵  Department of Astronomy and Physics, Saint Mary’s University, B3H 3C3, Halifax, Nova Scotia, Canada
⁶  Department of Physics, University of Liverpool, L69 7ZE, Liverpool, UK
⁷  Department of Chemistry, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada
⁸  Department of Physics, North Carolina State University, 27695, Raleigh, NC, USA
⁹  Department of Physics, University of Toronto, M5S 1A7, Toronto, Ontario, Canada
¹⁰  Department of Physics, University of Arizona, 85721, Tucson, AZ, USA
¹¹  Département de physique, Université de Montréal, Montréal, H3C 3J7, Québec, Canada
¹²  Département de physique de génie physique et d’optique, Université de Laval, Laval, G1V 0A6, Québec, Canada
¹³  Department of Physics and Astronomy, University of British Columbia, V6T 1Z1, British Columbia, Canada
¹⁴  Department of Physics, University of Surrey, GU2 7XH, Guildford, UK
¹⁵  Department of Physics and Astronomy, University of Kentucky, 40506-0055, Lexington, KY, USA
¹⁶  Physics Department, Colorado School of Mines, 80401, Golden, CO, USA
¹⁷  Department of Physics, McMaster University, L8S 4L8, Hamilton, Ontario, Canada

mschumak@uoguelph.ca

Received 19 December 2008 / Revised version 31 March 2009 / Published online 9 June 2009

Abstract

The low-energy structures of the radioactive nuclei ^{20, 21}Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ∼ 5×10⁶ ions/s were accelerated to 1.7 MeV/A and Coulomb excited in a 0.5 mg/cm^{2 nat}Ti target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For ²¹Na, Coulomb excitation from the 3/2⁺ ground state to the first excited 5/2⁺ state was observed, while for ²⁰Na, Coulomb excitation was observed from the 2⁺ ground state to the first excited 3⁺ and 4⁺ states. For both beams, B ( L) values were determined using the 2⁺ 0⁺de-excitation in ⁴⁸Ti as a reference. The resulting B(E2) ↓ value for ²¹Na is 137±9 e²fm⁴, while the resulting B( L) ↓ values for ²⁰Na are 55±6 e²fm⁴ for the 3⁺ 2⁺, 35.7±5.7 e² fm⁴ for the 4⁺ 2⁺, and 0.154±0.030 μ_N² for the 4⁺ 3⁺ transitions. This analysis significantly improves the measurement of the ²¹Na B(E2) value, and provides the first experimental determination of B( L) values for the proton dripline nucleus ²⁰Na.

Correspondence: mschumak@uoguelph.ca

Communicated by Communicated by J. Äystö

© Società Italiana di Fisica, Springer-Verlag 2009

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