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 Results from SPIRAL using TIARA and EXOGAM Experimental details and beam time request Plan is to submit UK grant request to enhance Surrey contribution

monopole effect 1s 1/2 0d 3/2 0f 7/2 1p 3/2 N=16 Z=14Otsuka PRL Magic Numbers below 40 Ca Z=8 0s, 1p } 0d 5/2 1s 1/2 0d 3/2 0f 7/2  24 O ( 25 O) 30 Si ( 31 Si) EXOTICSTABLE 0s, 1p  0d 5/2 0d 3/2 empty 0d 3/2

N=16 / N=20 Development 0s, 1p 0d 5/2 1s 1/2 0d 3/2 0f 7/2  24 O ( 25 O) 30 Si ( 31 Si) empty 0s, 1p  0s, 1p  26 Ne ( 27 Ne) ? N=16 (N=17) Measure energies of 3/2 +  1/2 + in 26 Ne and maybe 7/2 – in 27 Ne using the (d,p) reaction

N=16 / N=20 Development 0s, 1p 0d 5/2 1s 1/2 0d 3/2 0f 7/2  22 O ( 23 O) 28 Si ( 29 Si) empty 0s, 1p  0s, 1p  24 Ne ( 25 Ne) ? N=14 (N=15) Step down by 2 neutrons

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

N=16 / N=20 Development 0s, 1p 0d 5/2 1s 1/2 0d 3/2 0f 7/2  22 O ( 23 O) 28 Si ( 29 Si) empty 0s, 1p  0s, 1p  25 Na ( 26 Na) ? N=14 (N=15)

N=16 / N=20 Development 0s, 1p 0d 5/2 1s 1/2 0d 3/2 0f 7/2  24 O ( 25 O) 30 Si ( 31 Si) empty 0s, 1p  0s, 1p  27 Na ( 28 Na) ? N=14 (N=15) Low Lying   “gs” multi- plet

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

TIARA

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

V. Tripathi, S.L. Tabor, P.F. Mantica et al., Phys. Rev. Lett. 94 (2005) Na some of the right states, very poor ID and no negative parity 28 Na none of the negative parity states, which we seek, could be populated S. Lee, S.L. Tabor et al., Phys. Rev. C73 (2006) (s 1/2 )  (d 5/2 ) 3 J=3/2  1 +,2 + (s 1/2 )  (d 5/2 )  2 +,3 + (d 3/2 )  (d 5/2 )  (4,3,2,1) + (f 7/2 )  (d 5/2 ) (p 3/2 )  (d 5/2 ) (f 7/2 )  (d 5/2 ) (p 3/2 )  (d 5/2 ) (s 1/2 )  (d 5/2 )  2 +,3 +

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

Mirror reaction technique to measure (p,  ) for extreme proton rich nuclei Natasha Timofeyuk (Surrey) Idea: infer  p for proton-rich by measuring neutron ANC for (d,p) in mirror SpSp SnSn (d,p) A XA X Z X N A X'A X' N X Z proton  p neutron ANC 24 Al Si Na Na 

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

v cm is the velocity of the centre of mass, in the laboratory frame MRMR MPMP q f  v cm veve ( = ) 1/2 q f f=sin  max f = 1/2 for (p,d), 2/3 for (d,t) q  1 + Q tot / (E/A) beam Inverse Kinematics

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

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

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

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

Spec. Factors + Gammas for ID and Fitting 25 Ne (d,p) TIARA 10 5 pps 24 Ne for ~24 hours, poor gamma electronics

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

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

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

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

REQUEST TO THE EEC: Initial experiment using beam of 25 Na at several  10 5 pps ISAC-II at 4.5 MeV/A for 20 shifts of 12 hours Six Ge clovers (TIGRESS) New Si Box Reaction Array IF POSSIBLE, COMMENT ALSO: Subsequent experiment using beam of 24 Na at several x 10 6 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 27 Na at several  10 3 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, 27 Al contamination 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

SurreyYork COLLABORATION TIARA T IGRESS