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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 - PowerPoint PPT Presentation
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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
monopole effect
1s1/2
0d3/2
0f7/2
1p3/2
N=16
Z=14 Otsuka PRL 87 082502
Magic Numbers below 40Ca
Z=8
0s, 1p 0s, 1p
}
0d5/2
1s1/2
0d3/2
0f7/2
24O (25O) 30Si (31Si)EXOTIC STABLE
0s, 1p 0s, 1p
0d5/2
0d3/2
empty
0d3/2
N=16 / N=20 Development
0s, 1p 0s, 1p
0d5/2
1s1/2
0d3/2
0f7/2
24O (25O) 30Si (31Si)
empty
0s, 1p 0s, 1p
0s, 1p 0s, 1p
26Ne (27Ne)
?
N=16 (N=17)Measure energies of 3/2+ 1/2+ in 26Neand maybe 7/2– in 27Neusing the (d,p) reaction
N=16 / N=20 Development
0s, 1p 0s, 1p
0d5/2
1s1/2
0d3/2
0f7/2
22O (23O) 28Si (29Si)
empty
0s, 1p 0s, 1p
0s, 1p 0s, 1p
24Ne (25Ne)
?
N=14 (N=15)
Step down by2 neutrons
1/2+ is g.s. in 25Ne - canmeasure 3/2+ energy directlyand maybe 7/2– in 25Ne also,using the (d,p) reaction on 24Ne
N=16 / N=20 Development
0s, 1p 0s, 1p
0d5/2
1s1/2
0d3/2
0f7/2
22O (23O) 28Si (29Si)
empty
0s, 1p 0s, 1p
0s, 1p 0s, 1p
24Ne (25Ne)
?
N=14 (N=15)
N=16 / N=20 Development
0s, 1p 0s, 1p
0d5/2
1s1/2
0d3/2
0f7/2
22O (23O) 28Si (29Si)
empty
0s, 1p 0s, 1p
0s, 1p 0s, 1p
25Na (26Na)
?
N=14 (N=15)
N=16 / N=20 Development
0s, 1p 0s, 1p
0d5/2
1s1/2
0d3/2
0f7/2
24O (25O) 30Si (31Si)
empty
0s, 1p 0s, 1p
0s, 1p 0s, 1p
27Na (28Na)
?
N=14 (N=15)
LowLying
“gs”multi-plet
0.8 MeV
N = 17
Low-LyingNegative Parity
Multiplet in 28Na
… And the nextisotopes enter the Island of Inversion
Y. Utsuno, T. Otsuka et al., Phys. Rev. C70 (2004) 044307,“In the N=20 region, as we shall illustrate, the Na isotopesgive indispensable information on this shell evolution…”
TIARA
V. Tripathi, S.L. Tabor, P.F. Mantica et al., Phys. Rev. Lett. 94 (2005) 162501
26Na some of the right states,very poor ID and no negative parity
28Na none of the negative parity states,which we seek, could be populated
S. Lee, S.L. Tabor et al., Phys. Rev. C73 (2006) 044321
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) 162501
26Na some of the right states,very poor ID and no negative parity
28Na none of the negative parity states,which we seek, could be populated
S. Lee, S.L. Tabor et al., Phys. Rev. C73 (2006) 044321
(s1/2)(d5/2)3J=3/21+,2+
(s1/2)(d5/2)2+,3+
(d3/2)(d5/2)(4,3,2,1)+
(d3/2)(d5/2)(4,3,2,1)+
(f7/2)(d5/2)(p3/2)(d5/2)
(f7/2)(d5/2)(p3/2)(d5/2)
(s1/2)(d5/2)2+,3+
35Ar(p,)36K32Cl(p,)33Ar
24Al(p,)25Si
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) 1185H. 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
Sp
Sn(d,p)
A XZ X N
A X'N X Z
protonp
neutronANC
24Al13 11
25Si14 11
25Na11 14
24Na11 13
Note: although we list all of these important states here, mainly usingshell 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 J
vcm is the velocity of the centre of mass, in the laboratory frame
MR
MPq f vcm
ve (= )1/2
q f
f= sin-1max
f = 1/2 for (p,d), 2/3 for (d,t)q 1 + Q tot / (E/A) beam Inverse Kinematics
25Na(d,p)26Na and related reactions at 4.5 MeV/Ain inverse kinematics
25Na(d,p)26Na and related reactions at 4.5 MeV/Ain inverse kinematics
25Na(d,p)26Na and related reactions at 4.5 MeV/Ain inverse kinematics
TIARA24Ne(d,p)25Ne at 10 MeV/A at SPIRAL/GANIL
in inverse kinematics
Spec. Factors + Gammas for ID and Fitting
25Ne
(d,p)
TIARA105 pps 24Ne for ~24 hours, poor gamma electronics
+ TIARA
W.N. Catford et al.
SurreyPaisleyDaresburyLPC CaenLiverpool
York UK (funding), Colorado, Surrey, Daresbury et al.(no name as yet - ??? SiBRA with TIGRESS ???)
Silicon Strip Detector Box to cover all relevant angleswith the necessary angular resolution & low threshold
Photopeak Efficiency – 12 Detectors(Multiplicity 1)
Photopeak Efficiency – 8 Detectors(Multiplicity 1)
Photopeak Efficiency – 6 Detectors8% (1 MeV) (about 50% of TIARA+EXOGAM)
• 25Na(d,p)– E = 4.5 MeV/nucleon– Q = 3.391 MeV– Excited States: 0, 1.513, 1.661 MeV– Target = 100, 500 g/cm2
• Example: Target thickness = 100 g/cm2
• Actual Si Box geometry
Fred SarazinMatt Porter-PedenLuke EriksonColorado School of Mines
150 keVapart
Géant4Reconstructed
Ang Dist + actual
ReconstructedExcitation Energy
REQUEST TO THE EEC:
Initial experiment using beam of 25Na at several 105 ppsISAC-II at 4.5 MeV/A for 20 shifts of 12 hoursSix Ge clovers (TIGRESS)New Si Box Reaction Array
IF POSSIBLE, COMMENT ALSO:
Subsequent experiment using beam of 24Na at several x 106 ppsISAC-II at 4.5 MeV/A for 14 shifts of 12 hoursEight 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 hours10 to 12 Ge clovers (TIGRESS)Further development of beam purity, 27Al 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
Surrey York
COLLABORATION
TIARA TIGRESS
