{alpha} decay studies of very neutron-deficient francium and radium isotopes

Journal Article · Tue Feb 01 04:00:00 EST 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.024306· OSTI ID:20695933

Uusitalo, J; Leino, M; Enqvist, T; Grahn, T; Greenlees, P T; Jones, P; Julin, R; Juutinen, S; Keenan, A; Kettunen, H; Koivisto, H; Kuusiniemi, P; Leppaenen, A -P; Nieminen, P; Pakarinen, J; Rahkila, P; Scholey, C ^[1]; Eskola, K ^[2]

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1. Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014, Jyvaeskylae (Finland)
2. Department of Physics, University of Helsinki, FI-00014, Helsinki (Finland)

Very neutron-deficient francium and radium isotopes have been produced in fusion evaporation reactions using {sup 63}Cu and {sup 65}Cu ions on {sup 141}Pr targets and {sup 36}Ar ions on {sup 170}Yb targets. The gas-filled recoil separator RITU was employed to collect the fusion products and to separate them from the scattered beam. The activities were implanted into a position-sensitive silicon detector after passing through a gas-counter system. The isotopes were identified using spatial and time correlations between the implants and decays. Two new {alpha} decaying radium isotopes, {sup 201}Ra and {sup 202}Ra, were identified. The {alpha} decay energy and half-life of {sup 203}Ra were measured with improved precision. The {alpha} decay properties measured for the francium isotopes {sup 201}Fr,{sup 202}Fr,{sup 203}Fr, and {sup 204}Fr were confirmed, in many cases with improved precision. For the first time, a ({pi}s{sub 1/2}{sup -1})1/2{sup +} proton intruder state was identified in francium isotopes, namely in {sup 201}Fr and tentatively in {sup 203}Fr. The measured decay properties for the neutron-deficient odd-mass Fr isotopes suggest an onset of substantial deformation at N=112.

• OSTI ID: 20695933
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 71; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
ARGON 36 REACTIONS
COPPER 63 REACTIONS
COPPER 65 REACTIONS
CORRELATIONS
DEFORMED NUCLEI
ENERGY LEVELS
FRANCIUM 201
FRANCIUM 202
FRANCIUM 203
FRANCIUM 204
HALF-LIFE
HEAVY ION FUSION REACTIONS
NUCLEAR DEFORMATION
PARITY
PRASEODYMIUM 141 TARGET
PROTONS
RADIUM ISOTOPES
SPIN
YTTERBIUM 170 TARGET