Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 51 (2018)

RI beam production at BigRIPS in 2017
D. S. Ahn,∗1 N. Fukuda,∗1 H. Suzuki,∗1 Y. Shimizu,∗1 H. Takeda,∗1 T. Sumikama,∗1 N. Inabe,∗1 J. Amano,∗1,∗2
K. Kusaka,∗1 Y. Yanagisawa,∗1 M. Ohtake,∗1 T. Komatsubara,∗1 H. Sato,∗1 K. Yoshida,∗1 and H. Ueno∗1
Seven experiments were conducted in the 238 U beam
campaign that was started in May. The 167 Sm, 149 Xe,
130Ag, 84 Zn beams were delivered to the ZeroDegree
spectrometer for BRIKEN experiments. The 200 Wbeam was produced for neutron-rich nuclei around theN = 126 using a projectile-fragmentation of the 238 U
beam as a machine study.4) The 79 Se and 107 Pd beams
were produced for OEDO commissioning with the ImPACT program.
The spring beam time ended with an 18 O beam campaign, in which three experiments were performed.
The 1 H and 6, 8 He beams were produced for theSAMURAI experiment.
In the autumn beam time, the 238 U beam campaign
was started in October with eight experiments. The93Zr, 107 Pd, and 77, 79 Se isotope beams were providedwith the ImPACT program. The BRIKEN experiments were performed to measure the multi-neutron
emission probabilities and to search for new isotopes.5)
An experiment with two-step reaction scheme wasperformed to measure the production cross sectionsof the 125–128 Pd beam from the 132 Sn beam using
the BigRIPS and the ZeroDegree spectrometer.6) The

The radioactive isotope (RI) beam production at
the BigRIPS fragment separator1) in 2017 is presented
here. Table 1 summarizes the experimental programs
that involved the use of the BigRIPS separator during this period and the RI beams produced for eachexperiment.
The spring beam time started with a 48 Ca primarybeam in March. The experiment was performed tosearch for the existence of a new 39 Na isotope and todetermine the neutron dripline of neon isotopes.2) The
parasite BRIKEN experiment was performed to measure the multi-neutron emission probabilities.
Four experiments were conducted in the 70 Zn beam
campaign that was started in April. The 40, 50, 52 Ca
beams were delivered to the SAMURAI spectrometer
to measure the electric dipole response of the neutronrich Ca isotopes. The experiment to search for newneutron-rich isotopes was performed with the BigRIPS
separator in the region of 60 Ca isotope.3) A total of 8
new isotopes was identified in the preliminary analysis. The SEASTER experiment was performed with63
V, 57 Sc, 53 K to understand the evolution of the shellstructure towards the dripline.

Table 1. List of experimental programs and RI beams produced at the BigRIPS separator in 2017.
Primary beam
(Period)48Ca
345 MeV/nucleon(Mar. 30 – Apr. 2)
Zn345 MeV/nucleon(Apr. 11 – May 15)70

U345 MeV/nucleon(May 30 – Jun. 21)
238O
220 MeV/nucleon(Jun. 24 – July 14)
18

U345 MeV/nucleon(Oct. 21 – Nov. 30)
238

∗1
∗2

Proposal No.

CourseRI beams

DA16-01-01

ZeroDegree39

Na, 36Ne

PE16-04

ZeroDegree40

Mg,37Na (parasite experiment)

NP1312-SAMURAI9R1-01
NP1406-RIBF44R1-02
NP1512-SAMURAI38R1&39R2-01
DA17-01-01
NP1512-RIBF139-02
NP1406-RIBF127R1-02
NP1406-RIBF128-02
NP1612-RIBF148-01
MS-EXP17-02
MS-EXP17-04
IMPACT17-01
NP1406-SAMURAI19R1-01
NP1512-SAMURAI37-01
NP1512-SAMURAI34-01
IMPACT17-02-01
DA17-02-01
IMPACT17-02-02
MS-EXP17-03
NP1512-RIBF139-03
NP1612-RIBF148-02
NP1306-RIBF102-01
MS-EXP17-05

SAMURAIBigRIPSSAMURAISAMURAI

44, 50, 52

ZeroDegree

167

BigRIPS
ZeroDegree
SHARAQSAMURAISAMURAISAMURAISHARAQ
ZeroDegree
SHARAQ
PALISW
U (primary beam)
79
Se, 107Pd
1
H, 6, 8He
6, 8
He
1H, 8He93
Zr, 107Pd
82
Cu
77, 79Se
66
Cu

ZeroDegree

100

ZeroDegree
Rare-RI Ring

126, 128

RIKEN Nishina Center
Department of Physics, Rikkyo University- 79 -CaAr, 53Cl, 57K, 52, 54, 60Ca, 50S
63
V, 57Sc, 53K
53
K
52-54

Sm, 149Xe, 130Ag, 84Zn

200
238

78

Br, 102Sr, 106Zr, 112Mo, 115Nb

GePd, 132Sn

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 51 (2018)

Table 2. Number of experiments performed using RI beams in each year.

Year

238

U2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
Total

42
3
4
6
4
11
15
13
1375

124

Xe

86

Kr

78

Kr70Zn

48

1

4
3
10

2
3
2
6

1
8

1

Ca

6

1

4

1

3
4
62
36

4
6

18

O

126323
17

16

O

14

N

324He

1

112

H

111
513Yearlytotal
561014820917262222159Fig. 1. RI beams produced in 2017 and the production yield measured from March 2007 to December
2017 at the BigRIPS separator.

autumn beam time ended with a machine study of theRare-RI Ring experiment using the 78 Ge beam.
The number of experiments using the RI beams at
the BigRIPS separator is summarized in Table 2 forvarious primary beams in each year. A total of 159 experiments have been performed so far. Figure 1 shows
the RI beams produced in 2017 at the BigRIPS separator on the chart of nuclides with red squares.The
number of RI beams produced in 2017 is 50. The production yields for 1593 RI beams were measured fromMarch 2007 to December 2017, and they are indicatedusing green color. The yellow color indicates the known
isotopes.
References
1) T. Kubo, Nucl. Instrum. Methods Phys. Res. B 204, 97(2003).
2) D. S. Ahn et al., in this report.
3) O. B. Tarasov et al., in this report.
4) N. Fukuda et al., in this report.
5) Y. Shimizu et al., in this report.
6) H. Suzuki et al., in this report.

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