Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 50 (2017)

RI beam production at BigRIPS in 2016
H. Takeda,*1 N. Fukuda,*1 Y. Shimizu,*1 H. Suzuki,*1 D. S. Ahn,*1 T. Sumikama,*1 D. Murai,*1,*2 J. Amano,*1,*2 N. Inabe,*1K. Kusaka,*1 M. Ohtake,*1 Y. Yanagisawa,*1 T. Komatsubara,*1 H. Sato,*1 and K. Yoshida*1Five experiments were conducted in the second 238U
beam campaign started in May. The 132Sn and 48Ca beams
were produced for the ESPRI experiment. The 132, 124Sn andZ = 1í3 beams were delivered to the SAMURAI
spectrometer for symmetry-energy studies. The ImPACT
program was performed using the 93Zr beam with energies
of 200, 100, 50, and 20 MeV/nucleon. The 87Zn setting wasprovided for measurements of masses and beta-decay
properties of r-process nuclei around N = 56. 60Ti and 64V
were produced to study the shape coexistence along N = 40.
The spring beam time ended with an 18O beam campaign,in which two experiments were performed. First, 3H and4, 8
He beams were produced for the confirmation oftetra-neutron resonance. Subsequently, 4, 6He beams weredelivered for the measurement of vector analyzing powers.

The radioactive isotope (RI) beam production at theBigRIPS fragment separator1) in 2016 is presented here.
Table 1 summarizes the experimental programs thatinvolved the use of the BigRIPS separator in this period andthe RI beams produced for the programs.
The spring beam time started with a 238U primary beamin April. A machine study of the SAMURAI-TPC and themeasurement of the giant monopole resonance wereperformed with the 132Sn beam produced by the in-flightfission of 238U.
Subsequently, a 124Xe primary beam was used to produce
108, 112
Sn for symmetry-energy studies. The production
yields and the production cross sections of neutron-deficientisotopes for the Br í Cd region2) were measured during theBigRIPS tuning for the 124Xe beam.

Table 1. List of experimental programs and RI beams produced at the BigRIPS separator in 2016.
Primary beam (Period)
238
U
345 MeV/nucleon(Apr. 6 – Apr. 22)
124
Xe
345 MeV/nucleon(Apr. 29 – May 6)
238

U345 MeV/nucleon(May 14 – Jun. 13)
18

O230 MeV/nucleon(Jun. 16 – Jun. 30)
238

U345 MeV/nucleon(Oct. 19 – Nov. 12)

48Ca
345 MeV/nucleon(Nov. 15 – Dec. 6)*1*2

Proposal No.
MS-EXP16-01

Spokesperson
T. Isobe

CourseRI beams

SAMURAI

132

Sn
Sn

NP1312-RIBF113-01

S. OtaZeroDegree132

NP1312-SAMURAI22-01

T. Murakami

SAMURAI108, 112

NP1512-RIBF79R1-01
NP1312-SAMURAI15-01
IMPACT16-01
NP1306-RIBF106-01
NP1512-RIBF140-01

J. Zenihiro
W. Lynch
H. Sakurai
A. Estrade
F. Recchia

F12
SAMURAI
ZeroDegree
EURICAEURICA

132

NP1512-SHARAQ10-01

S. Shimoura

SHARAQ

3

NP1206-SAMURAI13-01

S. Sakaguchi

SAMURAI4, 6

ZeroDegree
PALIS
Rare-RI Ring
BigRIPS
PALIS
ZeroDegree
SAMURAISAMURAI
ZeroDegree
ZeroDegree
ZeroDegree
SAMURAI126, 127

IMPACT16-02
MS-EXP16-05
MS-EXP16-10
NP1412-RIBF123R1-01
PE16-03
PE16-01
NP1512-SAMURAI36-01
NP1406-SAMURAI27-01
NP1412-RIBF132-01
NP1312-RIBF03R1-02
PE16-02
NP1306-SAMURAI20-01

H. Sakurai
T. Sonoda
Y. Yamaguchi
M. Takechi
T. Sonoda
S. Nishimura
N. OrrN. Kobayashi
R. Kanungo
P. Fallon
S. Nishimura
C. Caesar

RIKEN Nishina Center
Department of Physics, Rikkyo University- 83 -Sn

Sn, 48Ca
Sn, 2H/4He/6Li
93Zr
87
Zn
60
Ti, 64V
132, 124

H, 4, 8HeHe
Sn, 93Zr, 107Pd

116

PdZn

76

59-78

Ni, 45-50Ca

20

C, 22C/23N
Ne, 30, 31Ne, 32Ne/34Na
27, 29F, 20, 22C, 19B
22

41

Al

26, 27F, 24ORIKEN Accel. Prog. Rep. 50 (2017)

Ⅱ-1. Nuclear Physics

In the autumn beam time, 238U and 48Ca primary beams
were used. The 238U beam campaign started in October withthe ImPACT program and the PALIS machine study. The Sn,Zr, and Pd isotope beams were provided. A machine studyof the Rare-RI Ring was conducted with the 76Zn beam. Alarge variety of Ni and Ca isotope beams were produced forthe determination of neutron skin thickness.
After switching to the 48Ca primary beam, the production
cross sections of Ne isotopes were measured3) during theBigRIPS tuning of the 48Ca beam. C – Na isotope beams
were produced for two SAMURAI experiments. Proton andmatter radii were measured with 27, 29F, 20, 22C, and 19B
beams to study the evolution of halo structure of theBorromean nuclei. The 41Al beam was produced for thestudy of 40Mg spectroscopy. The 26, 27F and 24O beams wereused to measure the lifetime of the 26O ground state. At theend of the 48Ca beam campaign, searches for a new isotope
39
Na and the neutron drip line were scheduled but

postponed because of a problem in the refrigerator ofsuperconducting magnets of the BigRIPS separator.
The number of experiments using the RI beams at theBigRIPS separator is summarized in Table 2 for various
primary beams in each year. A total of 137 experiments
have been performed so far. Figure 1 shows the RI beams
produced at the BigRIPS separator from March 2007 toDecember 2016 on the chart of nuclides. The number of RI
beams produced at the BigRIPS separator is approximately
440. The number of new isotopes is approximately 150.
Production yields for more than 1500 RI beams have beenmeasured.
References
1) T. Kubo, Nucl. Instr. Meth. Phys. Res. B 204, 97 (2003).
2) H. Suzuki et al.: In this report.
3) D. S. Ahn et al.: In this report.

Table 2. Number of experiments performed using RI beams in each year.
Year2382007
200820092010
2011
201220132014
2015
2016
Total

423U

4641115
1362

124

Xe

86Kr78

Kr70

Zn48

Ca

18O

16O

14N

4

He

2

H

1
43
102
32

1

4

13
4
6
34

6
1
8

1

62

32

12
6
3

1
1

12
14

1

11
5

13

Yearly
total
5
6
10
14
8
20
9
17
26
22137

Fig. 1. RI beams produced at the BigRIPS separator from March 2007 to December 2016.

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