Single neutron emission following llLi fl-decay

The spectrum of neutrons emitted after the B-decay of ~Li has been measured with a large time-of-flight array. The spectrum exhibits six peaks corresponding to neutron emission from known states in the l lBe daughter nucleus. The measured branching ratios indicate significant feeding to states over a broad energy range. The energies and parities of the states are in very good agreement with the previous results of the 9Be(t,p) reaction. Comparison of the present results with shell model calculations indicate the effect of the two neutron halo in HLi. The betadelayed neutron spectrum of SHe was determined in order to remove contributions from beam contamination. @ 1997 Elsevier Science B.V. PACS." 27.20.+n, 23.40.-s l Present Address: Department of Chemistry, Indiana University, Bloomington, IN-47405, USA. 2 Permanent Address: LPC-ISMRA, Boulevard du Marechal Juin, 14050 Caen Cedex, France. 3 Present Address: Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA. 4 Permanent Address: Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS 39762, USA. 5 Permanent Address: Department of Chemistry and Cyclotron Institute, Texas A & M University, College Station, TX 77843, USA. 6 Permanent Address: Canberra Industries, 800 Research Parkway, Meriden, CT 06450-7122, USA. 0375-9474/97/$17.00 @ 1997 Elsevier Science B.V. All rights reserved. PII S 0 3 7 5 9 4 7 4 ( 9 7 ) 0 0 4 1 0-7 D.J. Morrissey et al. /Nuclear Physics A 627 (1997) 222-238