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1107

1107. Series of related experiments; first for transfer with TIGRESS Nuclear structure motivation for 25,27 Na beams Nuclear astrophysics motivation for 24 Na beam Nucleon transfer – specifically (d,p) – in inverse kinematics Cross section calculations using ADWA

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1107

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  1. 1107 • Series of related experiments; first for transfer with TIGRESS • Nuclear structure motivation for 25,27Na beams • Nuclear astrophysics motivation for 24Na beam • Nucleon transfer – specifically (d,p) – in inverse kinematics • Cross section calculations using ADWA • Results from SPIRAL using TIARA and EXOGAM • Experimental details and beam time request • Plan is to submit UK grant request to enhance Surrey contribution

  2. Magic Numbers below 40Ca 1p3/2 0f7/2 0d3/2 1s1/2 Z=8 Z=14 Otsuka PRL 87 082502 N=16 EXOTIC STABLE 30Si (31Si) 24O (25O) 0f7/2 0d3/2 } monopole effect 0d3/2 0d3/2 1s1/2 empty 0d5/2 0d5/2 0s, 1p 0s, 1p 0s, 1p 0s, 1p p n p n

  3. N=16 / N=20 Development N=16 (N=17) Measure energies of 3/2+ 1/2+ in 26Ne and maybe 7/2– in 27Ne using the (d,p) reaction 26Ne (27Ne) 30Si (31Si) 24O (25O) 0f7/2 ? 0d3/2 1s1/2 empty 0d5/2 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p p n p n p n

  4. Step down by 2 neutrons N=16 / N=20 Development N=14 (N=15) 24Ne (25Ne) 28Si (29Si) 22O (23O) 0f7/2 ? 0d3/2 1s1/2 empty 0d5/2 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p p n p n p n

  5. N=16 / N=20 Development N=14 (N=15) 1/2+ is g.s. in 25Ne - can measure 3/2+ energy directly and maybe 7/2– in 25Ne also, using the (d,p) reaction on 24Ne 24Ne (25Ne) 28Si (29Si) 22O (23O) 0f7/2 ? 0d3/2 1s1/2 empty 0d5/2 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p p n p n p n

  6. N=16 / N=20 Development N=14 (N=15) 25Na (26Na) 28Si (29Si) 22O (23O) 0f7/2 ? 0d3/2 1s1/2 empty 0d5/2 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p p n p n p n

  7. N=16 / N=20 Development N=14 (N=15) 27Na (28Na) 30Si (31Si) 24O (25O) Low Lying   0f7/2 ? “gs” multi- plet 0d3/2 1s1/2 empty 0d5/2 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p 0s, 1p p n p n p n

  8. Y. Utsuno, T. Otsuka et al., Phys. Rev. C70 (2004) 044307, “In the N=20 region, as we shall illustrate, the Na isotopes give indispensable information on this shell evolution…” 0.8 MeV N = 17 Low-Lying Negative Parity Multiplet in 28Na … And the next isotopes enter the Island of Inversion

  9. TIARA

  10. Existing situation with spectroscopy of these n-rich Na isotopes 26Na some of the right states, very poor ID and no negative parity 28Na none of the negative paritystates, which we seek, could be populated S. Lee, S.L. Tabor et al., Phys. Rev. C73 (2006) 044321 V. Tripathi, S.L. Tabor, P.F. Mantica et al., Phys. Rev. Lett. 94 (2005) 162501

  11. n(f7/2)p(d5/2) n(p3/2)p(d5/2) n(d3/2)p(d5/2)(4,3,2,1)+ n(f7/2)p(d5/2) n(p3/2)p(d5/2) n(s1/2)p(d5/2)3J=3/21+,2+ n(s1/2)p(d5/2)2+,3+ n(s1/2)p(d5/2)2+,3+ n(d3/2)p(d5/2)(4,3,2,1)+ 26Na some of the right states, very poor ID and no negative parity 28Na none of the negative paritystates, which we seek, could be populated S. Lee, S.L. Tabor et al., Phys. Rev. C73 (2006) 044321 V. Tripathi, S.L. Tabor, P.F. Mantica et al., Phys. Rev. Lett. 94 (2005) 162501

  12. Breakout from the SCl cycle in the astrophysical rp -process Reactions considered to be important in gamma-ray bursters: Statistical model not appropriate because of low (p,g) Q-value 24Al(p,g)25Si 35Ar(p,g)36K 32Cl(p,g)33Ar S. Vouzoukas et al., Phys. Rev. C50 (1994) 1185 H. Herndl et al., Phys. Rec. C52 (1995) 1078

  13. AX AX' Z XN N XZ Mirror reaction technique to measure (p,g) for extreme proton rich nuclei Natasha Timofeyuk (Surrey) Idea: infer Gp for proton-rich by measuring neutron ANC for (d,p) in mirror Sn (d,p) Sp neutron ANC proton Gp   24Al 13 11 25Si 14 11 25Na 11 14 24Na 11 13

  14. Note: although we list all of these important states here, mainly using shell model energies, in 25Si only the 3.82 is measured and in 25Na there are 8 states in the region but only 2 with clear Jp

  15. ve MR 1/2 ) ( q f q f = @ vcm MP -1 q max = sin f q@ 1 + Q tot / (E/A) beam Inverse Kinematics f = 1/2 for (p,d), 2/3 for (d,t) vcm is the velocity of the centre of mass, in the laboratory frame

  16. 25Na(d,p)26Na and related reactions at 4.5 MeV/A in inverse kinematics

  17. 25Na(d,p)26Na and related reactions at 4.5 MeV/A in inverse kinematics

  18. 25Na(d,p)26Na and related reactions at 4.5 MeV/A in inverse kinematics

  19. TIARA 24Ne(d,p)25Ne at 10 MeV/A at SPIRAL/GANIL in inverse kinematics

  20. TIARA 105 pps 24Ne for ~24 hours, poor gamma electronics Spec. Factors + Gammas for ID and Fitting (d,p) 25Ne

  21. TIARA + W.N. Catford et al. Surrey Paisley Daresbury LPC Caen Liverpool

  22. NEW !! Silicon Strip Detector Box to cover all relevant angles with the necessary angular resolution & low threshold York UK (funding), Colorado, Surrey, Daresbury et al. (no name as yet - ??? SiBRA with TIGRESS ???)

  23. Photopeak Efficiency – 12 Detectors(Multiplicity 1) Photopeak Efficiency – 8 Detectors(Multiplicity 1) Photopeak Efficiency – 6 Detectors8% (1 MeV) (about 50% of TIARA+EXOGAM)

  24. 150 keV apart • 25Na(d,p) • E = 4.5 MeV/nucleon • Q = 3.391 MeV • Excited States: 0, 1.513, 1.661MeV • Target = 100, 500 mg/cm2 • Example: Target thickness = 100 mg/cm2 • Actual Si Box geometry Reconstructed Excitation Energy Reconstructed Ang Dist + actual Géant4 Fred Sarazin Matt Porter-Peden Luke Erikson Colorado School of Mines

  25. REQUEST TO THE EEC: Initial experiment using beam of 25Na at several  105 pps ISAC-II at 4.5 MeV/A for 20 shifts of 12 hours Six Ge clovers (TIGRESS) New Si Box Reaction Array • Commission Si Box array electronics, coincidence timing • Focus beam through Si Box and target • Assess scattered radioactivity, beam monitoring • Set up and operate zero degree detector IF POSSIBLE, COMMENT ALSO: Subsequent experiment using beam of 24Na at several x 106 pps ISAC-II at 4.5 MeV/A for 14 shifts of 12 hours Eight Ge clovers (TIGRESS) Further developments of zero degree beam dump and detector Subsequent experiment using beam of 27Na at several  103 pps ISAC-II at 4.5 MeV/A for 14 shifts of 12 hours 10 to 12 Ge clovers (TIGRESS) Further development of beam purity, 27Al contamination

  26. TIARA TIGRESS Surrey York COLLABORATION

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