Download - In-beam gamma-ray spectroscopy at RIBF
RCNP
In-beam gamma-ray spectroscopy at RIBF
AOI NoriRCNP Osaka Univ.
May 31, 2012NN2012
0. Introduction
1.Deep inside (or beyond) island-of-Inversion-- South of Island-of-Inversion-- East of Island-of-Inversion
2.Neutron rich Si isotopes N~28
3.Next step
RCNP
neutron skin
32Mg: large deformation
solar neutrino production
heavy hydrogens
explosive hydrogen burning
Nuclear Strucuter shell closure p & n decoupling
Astrophysics solar fusion explosive burning
16C: “egg” structure ? decoupled n-motion
28O: particle unstable
new magic #, N=16
neutron halo
molecular structure
neutron skin
Magic # (N=20) disappears.
Magic # (N=8) disappears.
Exotic structure in exotic nuclei
RCNP
neutron skin
32Mg: large deformation
solar neutrino production
heavy hydrogens
Exotic structure in exotic nuclei
explosive hydrogen burning
Nuclear Strucuter shell closure p & n decoupling
Astrophysics solar fusion explosive burning
16C: “egg” structure ? decoupled n-motion
28O: particle unstable
new magic #, N=16
neutron halo
molecular structure
neutron skin
Magic # (N=20) disappears.
Magic # (N=8) disappears.
RIBF More exotic Heavier nuclei
In beam-γ, First few years East and South of Island-of-inversion N~28
Intense 48Ca beam (~200pnA)
RCNP
• 2008 DayOne with 48Ca32Ne, 31,33Na
H. Scheit, P. DoornenbalPhys.Rev.Lett., 103:032501, 2009./Phys.Rev. C, 81:041305, 2010.
• 2010 48Ca campaign~42Si S. Takeuchi, M. MatsushitaA>36Mg P. Doornenbal, H. Scheit~Al, P David Steppenbeck
33Mg D. Bazin
• 2011 U campaign (~3 pnA)~132Sn H. Wang, NA
• 2012 Xe campaign~10xSn P. Doornenbal et al.
A. Obatelli et al.,
In-beam g-ray spectroscopy at RIBF
RCNPIsland-of-Inversion
31Na (Z=11, N=20)C. Thibault et al. PRC12(75)644
E.K. Warburton et al., PRC41(90)1147.
First proposed from massesMass
RCNPIsland-of-Inversion
31Na (Z=11, N=20)C. Thibault et al. PRC12(75)644
E.K. Warburton et al., PRC41(90)1147.
First proposed from massesMassEx(2+)moments…
RCNPStudy of Island-of-Inversion via 2+, 4+ states in E-E nuclei
Evolution of collectivity
B(E2;0+2+) : Measure of Collectivity
Ex(2+) : Alternative ∝ B(E2) (at least locally)
R4/2 = Ex(4+) / Ex(2+) : Type of Collectivity
( Ex in odd-A nuclei )
~
RCNPIsland-of-Inversion
T. Motobayashi et al., Phys. Lett. B346, 9(95)
Deformed (B(E2))
Deformed (Ex(2+))
RCNPIsland-of-Inversion before RIBF
Deformed (B(E2))
Deformed (Ex(2+))
RCNPFurther into and beyond Island-of-Inversion
Deformed (B(E2))
Deformed (Ex(2+))
?
RCNPBigRIPS/ZeroDegree @ RIBF
BigRIPS/ZeroDegree
RCNP
γ-ray spectroscopy setup @ BigRIPS/ZeroDegree
F7
F7
F5
F1
IRC
F2 F8
F11
F3
F12
ProductionTarget
SRC
1st stage separation 2nd stage
analysis ZeroDegreeanalysis of 2ndaryreaction products
Around the island of inversion (32Ne …), 42SiBut unable to continue due to activation problem.
Scheit et al.Takeuchi et al.
RCNP
F7
gTargetF7
F5
F1
IRC
F2 F8
F11
F3
F12
ProductionTarget
SRC
1st stage separation 2nd stage
analysis ZeroDegreeanalysis of 2ndaryreaction products
Around the island of inversion (32Ne …), 42SiBut unable to continue due to activation problem.
Scheit et al.Takeuchi et al.
γ-ray spectroscopy setup @ BigRIPS/ZeroDegree
Jan. 11, 2011
32Mg(p,p’) b~0.3
H.Hasegawa, Master’s thesis, Rikkyo Univ., 2003
Ener
gy (k
eV)
Emission angle of g rays 20°160°
RCNPFurther into Island-of-Inversion ?
Deformed (B(E2))
Deformed (Ex(2+))
?
RCNPSouth of Island-of-Inversion ?
? Deformed (B(E2))
Deformed (Ex(2+))
RCNP
• 32Ne : Ex (2+ )32Ne, 33Na + C 32Ne + g + X
RIBF DayOne experiment
• 29F : Ex (Jπ ),30Ne + C 29F + g + X
P. Doornenbal and H. Scheit et al., in preparation
Phys.Rev.Lett., 103:032501, 2009.
RCNP
Phys.Rev.Lett., 103:032501, 2009.
2+ states in 32Ne
RCNP
Phys.Rev.Lett., 103:032501, 2009.
2+ states in 32Ne
RCNP Further south, south of 30Ne ?
28O Unbound29F = 28O+p
28O
p
28O
p
RCNPExcited states in 29F
RCNPExcited states in 29F
RCNP
Deformed (B(E2))
Deformed (Ex(2+))
South of Island-of-Inversion ?
RCNP
Deformed (B(E2))
Deformed (Ex(2+))
South of Island-of-Inversion ?
RCNPEast of Island-of-Inversion
?
Deformed (B(E2))
Deformed (Ex(2+))
RCNP
• 36,38Mg : Ex (2+), Ex (4+)
37Al + C 36Mg + g + X39Al, 40Si + C 38Mg + g + X
• 36,38Mg : B(E2;0+2+1)
Coulex (38Mg+Pb) s B(E2)
P. Doornenbal and H. Scheit et al., in preparation
RCNP2+ state in 36,38Mg P. Doornenbal, H. Scheit et al.
C(37Al, 36Mg*)
C(37Al, 36Mg*)
C(40Si, 38Mg*)
C(39Al, 38Mg*)
RCNP2+ state in 36,38Mg P. Doornenbal, H. Scheit et al.
RCNPEast of Island-of-Inversion
?
Deformed (B(E2))
Deformed (Ex(2+))
RCNPEast of Island-of-Inversion
Deformed (B(E2))
Deformed (Ex(2+))
RCNPNorth-East of Island-of-Inversion
Deformed (B(E2))
Deformed (Ex(2+))
?
RCNPSpherical or deformed ? from R4/2
Deformed (B(E2))
Deformed (Ex(2+))N
A
R(4
/2)
Ex (M
eV)
?
?2+
4+
Si isotopeS isotope
R(4
/2)
Ex (M
eV)
2+
4+
Shape Coex.,C. Force et al.PRL 105, 2010.
RCNPSpherical or deformed ? from R4/2
Deformed (B(E2))
Deformed (Ex(2+))
RCNPSpherical or deformed ? from R4/2
Deformed (B(E2))
Deformed (Ex(2+))
?
RCNPWhat we know about 42Si.
b-decay experimentShort half-life Large deformation (possibly oblate), comparing with QRPA calculation.
S.Grevy et al., Phys. Lett. B 594, 252 (2004).
Mass measurementDeformed/Spherical?
B.Jurado et al., Phys. Lett. B 694, 43 (2007).
NSCL case A substantial Z=14 subshell
closure
J.Fridmann et al., Phys. Rev. C 74, 034313 (2006)
GANIL case Well-deformed oblate rotor
B.Bastin et al., Phys. Rev. Lett. 99, 022503 (2007).
Two-proton removal reactions, 44S 42Si
RCNP
• Ex of 2+ and (4+) states in 38,40,42Si40S + C 38Si + g + X 44S + C 40Si + g + X44S + C 42Si + g + X
S. Takeuchi and M. Matsushita et al. in preparation
RCNP42Si - g single spectrum -
44S + C 42Si + g + X
GANIL exp. : 770(19) keVB.Bastin et al., Phys. Rev. Lett. 99, 022503 (2007).
We confirmed g line observed at GANIL.
RCNP42Si - g single spectra -
g ray (2+0+): 742(8) keVnew lines:
1431(11) keV2032(9) keV2357(15) keV
*Widths are fixed to simulated values.
44S + C 42Si + g + X
RCNP
*Widths are fixed to simulated values.
44S + C 42Si + g + X
42Si - g-g spectra -
1431 keV
2032 keV ?
742 keV
2032 keV ?
742 keV
0+
2+1431 ke
V
Partner of 742 keV1431 keV2032 keV?
Partner of 1431 keV742 keV2032 keV?
?1431 keV
0 keV
2173 keV(4+)R4/2 = 2.9
RCNP
Gate on 1079keV
1079(6)
2210 : This Work( Ex(4+) )
Gate on 1079keV
Spectroscopy of 38Si and 40Si
Gate on 988keV
634(7)988(6)
1544(8) : This Work(4+2+)
40S + C 38Si + X + γ 44S + C 40Si + X + γ
RCNP
Gate on 1079keV
1079(6)
2210 : This Work( Ex(4+) )
Gate on 1079keVGate on 988keV
634(7)988(6)
1544(8) : This Work(4+2+)
40S + C 38Si + X + γ 44S + C 40Si + X + γ
38Si
1084
1126
1.08
2.21
2+
(4+)
40Si
988
1544
634
0.99
(1.62)
(4+)
2+
2.53
Spectroscopy of 38Si and 40Si
RCNP42Si: well deformed
N=28 isotones
A
ZR
(4/2
)E
x (M
eV)
Z=14 isotopes
N
A
R(4
/2)
Ex
(MeV
)
2+
4+
2+
4+
R(4/2) = 2.9336Si: ref: X.Liang et al., PRC74,014311(2006)46Ar: ref: Zs.Dombradi et al., NPA 727(2003)19544S: ref: D.Santiago-Gonzalez et al., PRC 83,061305R(2011)
RCNPNorth East of Island-of-inversion
Deformed (B(E2))
Deformed (Ex(2+))
?
RCNP
Deformed (B(E2))
Deformed (Ex(2+))
North East of Island-of-inversion
Potential Energy Surface
s1/2
proton
neutronf7/2d3/2
d5/2
full
Tensor force removedfrom cross-shell interaction
Strong oblateDeformation
Otsuka, Suzuki and Utsuno,Nucl. Phys. A805, 127c (2008)
exp.
4214Si28
42Si
Other calculations (RMF, Gogny)show oblate shape.
42Si 2+: Bastin, Grévy et al., PRL 99 (2007) 022503
(4+) : RIBF data 2011doublymagic ?
Z =14
p3/2N =28
repulsiveattractive
Otsuka-san’s talk (Wed)
RCNP
T.Otsuka et al., NPA 805 (2008) 127c
-- without tensor force spherical min.-- with tensor force oblate min.
Systematics of the 2+ and 4+ states in Si
Present exp.
RCNP
• 2008 DayOne with 48Ca32Ne, 31,33Na
H. Scheit, P. DoornenbalPhys.Rev.Lett., 103:032501, 2009./Phys.Rev. C, 81:041305, 2010.
• 2010 48Ca campaign~42Si S. Takeuchi, M. MatsushitaA>36Mg P. Doornenbal, H. Scheit~Al, P David Steppenbeck
33Mg D. Bazin
• 2011 U campaign (~3 pnA)~132Sn H. Wang, NA
• 2012 Xe campaign~10xSn P. Doornenbal et al.
A. Obatelli et al.,
In-beam g-ray spectroscopy at RIBF
RCNP
• 2008 DayOne with 48Ca32Ne, 31,33Na
H. Scheit, P. DoornenbalPhys.Rev.Lett., 103:032501, 2009./Phys.Rev. C, 81:041305, 2010.
• 2010 48Ca campaign~42Si S. Takeuchi, M. MatsushitaA>36Mg P. Doornenbal, H. Scheit~Al, P David Steppenbeck
33Mg D. Bazin
• 2011 U campaign (~3 pnA)~132Sn H. Wang, NA
• 2012 Xe campaign~10xSn P. Doornenbal et al.
A. Obatelli et al.,
In-beam g-ray spectroscopy at RIBF
RCNP
Nov07 Spiral2
Approved γ-ray spectroscopy experiments at BigRIPS
86Kr/136Xe/238U 1pμA
Calculation uses•86Kr + Be Fragmentation EPAX2•136Xe + Be Fragmentation EPAX2•238U + Be Fragmentation EPAX2
Fission DATA@GSI (limited)•238U + Pb Fragmentation EPAX2
Fission ABLABRA
N=20 N=28
N=50
N=82
N=126
Z=20
Z=28
Z=50
Z=82
r-process
86Kr/136Xe/238U 1pμA
RCNP
Nov07 Spiral2
Approved γ-ray spectroscopy experiments at BigRIPS
86Kr/136Xe/238U 1pμA
Calculation uses•86Kr + Be Fragmentation EPAX2•136Xe + Be Fragmentation EPAX2•238U + Be Fragmentation EPAX2
Fission DATA@GSI (limited)•238U + Pb Fragmentation EPAX2
Fission ABLABRA
N=20 N=28
N=50
N=82
N=126
Z=20
Z=28
Z=50
Z=82
r-process
86Kr/136Xe/238U 1pμA
RCNPNuclei around 132Sn:Te, Sn beam fragmentation
Z
52
48
50
44
54
46
2.4 2.5 2.6 2.7 A/Q
130Sn
134Te
130Cd
124Pd Pd
Cd
Sn
Te
Particle Identify of Ejected Fragmentation
Wang He, NA et al.
RCNP
Wang He, NA et al.
132Te 130Sn
g-ray peaks are clearly observed
RCNPCollaborators
RCNP: N. AOI
RIKEN: P.DOORNENBAL, S. TAKEUCHI, M. MATSUSHITA, H. WangJ.LEE, L.KUOANG, D.STEPPENBECK, W.HE, T.MOTOBAYASHI, H.SAKURAI, H.BABA, M.TAKECHI, Y.TOGANO, K.YONEDA
Darmstadt H.SCHEIT TITech: N.KOBAYASHI, G.LEE, Y.KONDO, T.NAKAMURA, T.SAKO, K.TAKAHASHICNS: S.GO, E.IDEGUCHI, S.MICHIMASA, S.OTA, S.SHIMOURATU Munchen: R.GERNHAEUSER, C.HINKE, R.KRUCKEN, K.STEIGERANL: C.HOFFMANGANIL: L.CACERESFrankfurt/GSI: T.L.BLEISIN2P3: S.GREVY, A.MATTALBNL: H.CRAWFORD, P.FALLON, M.PETRI,LPC CAEN: J.GIBELINNSCL: D.BAZIN, R.WINKLERRICHMOND: R.HUGHESYORK: D.JENKINS
RCNP
Deformed (B(E2))
Deformed (Ex(2+))
Extended view around Island-of-inversion
RCNP