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Superheavy nuclei: single-particle energies & limits Teng Lek Khoo. Single-particle energies Gaps in particle spectrum E shell s uperheavy nuclei. Necessary for accurate theoretical description . Magic gaps.
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Superheavy nuclei: single-particle energies & limitsTeng Lek Khoo Single-particle energies Gaps in particle spectrum Eshell superheavy nuclei. Necessary for accurate theoretical description. Magic gaps. Decisive tests of best models (e.g. demonstrated that DFTs need improvement). Data from decay spectroscopy: high-K isomers, α-, α-electron. Z = 107,108 Limits in I, E*, Z & N Bf(I,E*,Z,N) & Eshell(I,E*,Z,N). Data from in-beam spectroscopy: entry distributions (I,E) & high-spin structure. Z = 104, 106 T. L. Khoo, ATLAS W'shop 2009
T. L. Khoo, ATLAS W'shop 2009
Single-particle energies: “experiment” vs. theory Esp Proton Esp, valid to Z=102 (E2qp 254No) & Z=103 (E1qp255Lr) T. L. Khoo, ATLAS W'shop 2009
Initial states for γ decay to g.s. T. L. Khoo, ATLAS W'shop 2009
Imax(254No) > Imax(220Th)! Bf(254No) > Bf(220Th) (b)220Th90 176Yb(48Ca,4n) Imax =20 223 MeV (a) 254No102 Yield (arbitrary units) Imax =32 219 MeV Imax =20 >5 MeV ~8 MeV 0 20 I (hbar) 10 30 208Pb(48Ca,2n) T. L. Khoo, ATLAS W'shop 2009
Requirements(for Z = 103-108, > 0.1 nb) • High beam intensity: 1-5 pA • Efficient recoil separator >50%. New gas-filled separator. • Decay spectroscopy: efficient isomeric electron & array (>25% peak efficiency at ~300 keV). • In-beam spectroscopy: Gammasphere & Gretina; calorimetry for entry distribution measurements. T. L. Khoo, ATLAS W'shop 2009
extras T. L. Khoo, ATLAS W'shop 2009
Strategy • Compare experiment vs. theory. • For a theory to be credible, it must first be validated: it must at least correctly describe what is known. T. L. Khoo, ATLAS W'shop 2009
Proton gap (~2.2 MeV) at 114 – if WS continues to apply for Z>102. X X ? Where are the magic gaps? Macroscopic/Microscopic (MM), Skyrme (SHF) & Relativistic (RMF) mean field. T. L. Khoo, ATLAS W'shop 2009
Need data on nuclei with high ZZ ~103 -108 >~ 0.1 nbE(proton single-particle) Z = 114 gap.E(neutron single-particle) N = 184 gap T. L. Khoo, ATLAS W'shop 2009