Joint RIKEN-Kurchatov-Dubna experiments
at RIKEN
The collaboration exists since 1992 and is devoted to
studies of Light Exotic Nuclei
Research subjects (experimental):
Spectroscopy, investigation of Structure, studies of Scattering
8He
10He
12Be
13Be
11Li
14Be
6He
3H
5H
7He
7H
The first study of 8He scattering.
Search for excited state of 8He.
detector
missing mass method
8He + p  p + 8He*
6He + n + n
detector
invariant mass method
detector
detector
Invariant mass method
6He*
40
30
20
30
20
10
2
0
0 1 2 3 4 5 6
E*8 (MeV)
He
30
20
.
10
1
10
p+ 7He
40
counts
He*
Yield (a.u.)
Yield (a.u.)
40 8
Missing mass method
4He+n+n
0
3
2
1
0
-2 2 6 10 14 18
E plab (MeV)
6He+n+n
6
32 p+ He p+ 8He
16
0
56 64 72 80
lab
p
.
0
1
2
E*6
He
3
(MeV)
4
E*8
He
(MeV)
.
(~ 6)
3.11
4He+4n
3.57±0.12
2+
=0.5±0.35
2.58 7He
2.14
6He+n+n
0+
8He
Inelastic scattering 8He + p
Elastic scattering 8He + p
1000
10 1
1-
missing
invarinat
delastic/dRutherford
4.0
2+
10 0
d/  m
d  b
/s
r
5He
10 -1
100
1
4
10
3
2
10 -2
1
0o
20 o
40 o
cm
60 o
0o
20o
40o
cm
60o
80o
Search for 10He.
dipole magnet
drift chamber
Target
CD2/C
hodoscope
plastic scintillators
MWPCs
n
8He
11Li
B
n
neutron walls
8He+n+n
200
coincidences:
6He+n+n
10He:
Eobs = 1.1 ± 0.2 MeV
obs = 1.0 ± 0.4 MeV
800
Yield (a.u.)
Yield (a.u.)
8He*
1000
160
120
.
80
40
coincidences:
4
1
600
5
.
400
200
2
3
0
-2
0
2
4
E
6
8He-n-n
(MeV)
8
10
12
0
0
2
4
6
8
10
E*8 (MeV)
He
12
14
16
18
Spectroscopy of 12Be and 13Be.
dipole magnet
SSDs
drift chamber
plastic
target
scintillators
CH2/C MWPCs
hodoscope
70
60
240
Counts
200
12,11,10Be,
12Be
8,6,4He
50
12Be
g.s.
n
30
p
counts
10
0
0
120
2
4
6 8
*
E12
12Be
2.1
12Be
4.6
80
12Be
5.7
E*
8
p
SSDs
neutron walls
p(12Be,p)12Be
2
4
target
CD2/C
, M eV
12Be
10
1
0
10 12 14 16 18 20
Be
12Be
8.6
40
0
-4
12Be
Be
12
40
20
160
B
12
16
d(12Be,p)13Be
20
~14
(MeV)
12 Be
12.058
11.083
10.108
10±0.15
8.946
8.6±0.15
4
4
He+ He+4n
6
4
He+ He+2n
6
6
He+ He
8
4
He+ He
(~10)
(~7 )
(~5)
5.70
4.56
3.673
10
Be+2n
2.70
2.10
2.0
2+
+
0
12Be
3.168
11
Be+n
13Be
0
12
Be+n
Spectroscopy of 11Li and 14Be
by proton scattering.
dipole magnet
SSDs
drift chamber
plastic scintillators
target
CH2/C MWPCs
hodoscope
11,9,8Li,
14,12Be
10
.
B
11Li,
14Be
n
p
5
SSDs
neutron walls
0
0
2
4
E* (MeV)
6
8
100
inelastic
33
inelastic
10
122
11
d/d (mb/sr)
.
d/dE
d/dE** (mb/MeV)
(mb/MeV)
d/dE * (mb/MeV)
theory
1-
0++
1
10+
.1
00
-5
-5
00
55
10
10
(MeV)
EE**11 (MeV)
11Li
Li
15
15
.01
0
20
40
60
cm (deg)
80
14Be + p, 74 A MeV
120
30
.
p(14Be,p12Be)
p(14Be,p)
Counts/350 keV
Counts/350 keV
100
80
60
40
20
10
Be+4n
5.01
10
20
0
-4
30
0
4
8
12
16
0
-4
20
20
0
4
Counts/500 keV
Counts/500 keV
20
10
0
4
8
12
E*14 (MeV)
Be
16
12
16
(4.1 ± 0.2)
20
1.6 ± 0.1
p(14Be,np)
0
-4
8
20
p(14Be,pn12Be)
10
14Be
0
4
8
12
E*14 (MeV)
Be
16
20
(2+)
0+
0
0
-4
11
Be+3n
4.51
12
Be+2n
1.34
Scattering 6He+p and 3H+p.
dipole magnet
SSDs
drift chamber
plastic scintillators
target
CH2/C MWPCs
hodoscope
6,4He, 3H
B
6He,
3H
n
p
SSDs
neutron walls
6He
gs
6He*(2+)
Proton elastic scattering.
Drift chamber
Hodoscope
p
8He
p
t
n
beam scintillators
Neutron walls
Dipole magnet
Search for 7H
60
counts/1.5 MeV
50
40
30
20
10
0
-10
-20
E
7H
H2 cryogenic
target, GANIL
8He,t)
8He,t)
6He
6He
p(p(
H-target - empty-target
0
MWPCs
Structure of the 8He ground state
p(8He,pp)7H
-30
-30 -20 -10
RIKEN
telescope
10
(MeV)
20
30
Spectroscopy of 7He.
Drift chamber
Hodoscope
M. Meister et al.,
Phys. Rev. Lett. 88
(2002) 102501
Beam
scintillator
RIKEN
Telescope
d
6He,
4He
n
Dipole magnet
Neutron walls
counts
80
A.K. et al.,
Phys. Rev. Lett. 82
(1999) 3581
p(8He,d)7He
8He
Target
CH2,C
MWPCs
d+n+4He
H.G. Bohlen et al.,
Phys. Rev. C64
(2001) 024312
9Be(15N,17F)7He
40
20
0 10 20 30 40
E above n+6He(MeV)
7He
G.V. Rogachev et al.,
Phys. Rev. Lett. 92
(2004) 232502
6He(p,n)6Li(0+,T=1)
3.3±0.3 MeV
 ~ 2.2 MeV
1.80 MeV
n+6He*(2+)
3/2-
7He*(1/2-)
60
0 -10
(5/2-)
C(8He,n6He)
0.44 MeV
=0.16 MeV
0
n+6He
1.87 MeV
2n+5He
0.975 MeV
3n+4He
Theory predicts 7H*(5/2-):
S.C. Pieper et al.,
Phys. Rev. C64 (2001) 014001