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I
A. NavinA. NavinGANIL
Exclusive measurementswith weakly bound nuclei
•Is it really required, How far can we go with RIB
•What does one learn new
Conclusions
ØGreat Future with weakly bound Nucleiespecially with RIBs
Lots of new questions and anwersØNo limits, dream of it and we can make it
a reality
Correlations Stable weakly bound beams, Mumbaip γ6,7Li+60Ni Mixing of CN+direct reactions Fusion of WBN7Li+165Ho breakup fusion /transfer?
Ø Radioactive ion beams SPIRALp γ n6He+65Cu neutron correlations in borromean nucleiLimits 8He
POA
SHEERLUCK Holmes
Last Century nextdecade
Structure Reaction
Richness with skins,Tails and halosFUSION
Elastic scattering
BUF
transfer
4He 6He 8He
Sn(MeV) 20.58 1.863 2.583
S2n(MeV) 0.973 2.138
<r2>1/2 (fm) 1.67(01) 2.54(04) 2.49(04)
6Li 7LiSα/d Sα/t1.475 2.47
MeV
WB2WB1
7Li+60Ni
αt
67Ga
t+ (60Ni+α)
α + (60Ni+t)
α,t 60Ni
7Li+60Ni
Who is thefather ?
Intensity of low lying γ transitions à σER
Σ σE.R = σFUSION
66Cu
γ2+
0+
γ - ray detector array
68Ga68Zn
Projectile
6,8He Fusionp3n
5n α3n
4+Ga
69Ga
4n
Transfer
Si CDCD detectors EXOGAM Neutron Wall
Energy Angular correlations
Elastic Scattering Angular distibutions E-∆E CDCD detectors
6,7Li
65CuTarget
Neutron-WallEXOGAM
CD
Exclusive measurements
How do we do it
γ p n
7Li+60Ni, CASCADE
Elab15 20 25 30 35
σ F (
mb )
0.1
1
10
100
2n (65Ga) np (65Zn) 2p (65Cu) 2np (64Zn) 3n (64Ga) 2pn (64Cu) a (63Cu) an (62Cu) ap (62Ni) a2n (61Cu) anp (61Ni) 2a (59Co) 2an (58Co)
62Cu, 62Ni,61Cu,61Ni,58Co 63Zn, 60Ni
Satistical Model calculations(alpha+t)+Target
alpha+target, t+target
Stable Weakly bound Nuclei
Presence of two components in the alpha Spectraσnc~430mb and σcn=350mb
θlab
0 50 100 150
dσα/d
Ω (m
b/st
r)
100
101
102
7LI+60Ni 30 MeV
Eα
α angular distbn
Near and away from grazing angleNear and away from the barrier 15, 30 MeV
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 1601e-5
1e-4
1e-3
1e-2
1e-1
1e+0 theta_l vs sig/sigr OPM
α+t
(6),7Li+60Ni Mixing of CN+direct reactions
alpha particle spectra
Elab.
5 10 15 20
100
300Cou
nts/
0.5
keV
100
200
300
400
Eγ (keV)200 250 300 350 400 450 500
0
100
200
10 20 30
100
20061Ni
58Co62Cu61Cu
30 MeV
15 MeV
1200
400
1200
400
E α G
ate
8-13 M
eV
21-42
MeV
E α Gate
7.9-20
MeV
5.2-7.8
MeV
Eα Gate
4.5-8.6 MeV
8.6-15 M
eV
E α Gate
9.9-18.7 MeV
7.2-9.9 MeV
α- 62Cu30 MeV
Cou
nts
(arb
)
(1) (2)
(3)
400
1200
α- 62Cu15 MeV
1200
400
p-γAlpha Spectra ßà gamma spectra
40o grazing
120o grazing
Need for understanding the origin before extracting physics!
Transfer ?
Qopt
7Li + 60Ni
62Cu αn
E (keV)
184.6166Er
280.4166Er
184.6166Er
280.4166Er
365.5166Er
Different Routes Different Routes àà 166166ErErfrom t fusion/transfer and p transferfrom t fusion/transfer and p transfer
p transfer
t-transfer/fusion
Side feeding patternAngular momentum
7Li+165Hoà4He+(168Er)* t fusion/transferà6He+166Er proton transfer
77Li + Li + 165165Ho 42 Ho 42 MeVMeVBreakup fusion /transferBreakup fusion /transfer
Phys.Rev. C 72, 017601 (2005)
6He + 65Cu
σ(m
b)
102
103
2n 3np2np3n66Cuα2nα3n4n
4He + 65Cu
σE
R (m
b)
101
102
103
2n αn1ppn1np2n3nα
Ec.m. (MeV)15 20 25 30 35 40
σ (m
b)
0
500
1000
1500
4He+65Cu6He+65Cu
(c)
(a)
(b)
RIBBUY ONE (FUSION) GET ONE FREE (TRANSFER)
Evidence for non fusion processà TRANSFER(Same residue as from fusion)
σ (6He+Cu) = (6He+Cu)+(a+Cu) + (n+Cu)
Phys.Rev. C 70, 044601 (2004)
6He+238U
P.A. Young et al 6He+Bi Phys.Rev. C 71, 051601 (2005)Includes breakup
5He+66Cu 1n4He+(67Cu)* 2n
Transfer
Si CDCD detectors EXOGAM Neutron Wall
Energy Angular correlations
4He, 66Cu + n
Beam dumpFC (105pps)Neutron-WallEXOGAM
CD
6He+65Cu 1n and 2n transfer
What’s new at SPIRAL
p-γ-n correlations with RIB
(No breakup)
Angles (θ) of different rings :
18.5°, 30.3°, 34.9°, 46.8°, 47.2°, 57.2°Fifteen 5 x5inch hexagonal liquidscintillator
(BC501) detectors
- three segments for each
- Total of 45 separate detector
segments with its own PMT
Three signals per segment :
- TOF, ZCO and QVC
Target to focal point of N_Wall
- 57 cm
State of art: Triple coincidences 6He
6He + 65Cu - 5He + 66Cu*correlated α + nb (66Cu+γ)γ gate on 66Cu
6He + 65Cu - 4He + 67Cu*(uncorrelated) α (66Cu+γ) +nt
φn
φα
SimulationsExperiment
2n transfer 1n transfer
SPIRAL-I
El=23 MeV
18o-57o
20o-55o
4x107 /secTOF
ESi
γ gate on 66Cu γ gate on 68Zn (2np)
φn φn
φα
Bottom line: 1n and 2n transfer angular distribtions: Correlations
ϕn
ϕα
En
Eα
En
Eα
1n transfer 2 x105
2n transfer 6 x105
Simulations
How much 1n & 2nStructure of 6He 5+1, 4+2?
8He
• He anamoly• 4n skin/halo how does it different viz vis 6He• p-γ to get transfer angular distributionsMuch more later…..Elastic scattering, Fusion cross sections …..
Limits 8He+65Cu
Low ! ? intensity 1x105 20 and 30 meV Vb ~11 MeV
Coincidencetransitions
4He,6He
Qgg
8He+65Cu 7He+66Cu 4.482
6He+67Cu 14.04
5He+68Cu 18.49
4He+69Cu 27.65
(α3n)+66Cu CN
4He 6He
γ,n
A Neutron OR gatesB Si-γC Singles20 MeV, 30 MeV(scaled)
Absolute ER cross sections singles γwith a beam intensity 105 pps +…
68Ga
68Ga
68Ga 68Ga
68Ga
66Cu
A
B C
SPIRAL 2 SPIRAL 2
LINAG
LIRAT
LIRAT 2
C
Source
UCx2000°C
diffusion / effusiondeuterons40 MeV neutrons
1+ n+
C
Source
UCx2000°C
diffusion / effusiondeuterons40 MeV neutrons
1+ n+
Goal:1014 fissions/sGoal:1014 fissions/s
Linear deuteron and heavy-ion driver production of proton-rich and light RIBs
as well as future extension to higher energies -> synergy with EURISOL
Linear deuteron and heavy-ion driver production of proton-rich and light RIBs
as well as future extension to higher energies -> synergy with EURISOL
RFQRFQDeuteron source
5mADeuteron source
5mA
Superconducting LINACE = 14.5 AMeV for heavy Ions
A/q=3E = 40 MeV for deuterons
Superconducting LINACE = 14.5 AMeV for heavy Ions
A/q=3E = 40 MeV for deuterons
Production CaveC converter+UCx target
≤ 1014 fissions/s
Production CaveC converter+UCx target
≤ 1014 fissions/s
Light Intense: 15C
Ø15C Sn =1.2 Sp =21 MeV l=0, C2S=0.96 9Be(7Li,p)15C production
Ideal case for study of effect of WB on reaction mechanism
•Advantages over 11Be difficult Ref case9,10Be, no admixture of s1/2 and d5/2 in ψ
15C+144Sm--> 159Er Ref Case12C+144Sm--> 157Er
Weak and heavy2. Recent HRIBF Research -Measurement of E R at Sub-Barrier Energies 134Sn + 64Ni Feb 2005 (D. Shapira, Spokesperson)
136Sn 4x10 3 pps
Sn =3.7 MeV t1/2 0.25 secs136Sn+80Se 216Po
Letter of Intent in May
IPN, IN2P3-CNRS BHABHA ATOMIC RESEARCH CENTERTata Institute of Fundamental ResearchCEA/ SACLAY
GANILTIT, Japan
IKS, University of Leuven Daresbury LabsUniversity of Surrey
Uppsala University
Collaboration
SP3SP2