Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 47 (2014)

RIKEN Accel. Prog. Rep. 47 (2014)

Operations of RIBF ring cyclotrons (RRC, fRC, IRC, and SRC)
R. Koyama,∗2 T. Dantsuka,∗1 M. Fujimaki,∗1 T. Fujinawa,∗1 N. Fukunishi,∗1 S. Fukuzawa,∗2 M. Hamanaka,∗2H. Hasebe,∗1 Y. Higurashi,∗1 E. Ikezawa,∗1 H. Imao,∗1 S. Ishikawa,∗2 T. Kageyama,∗1 O. Kamigaito,∗1M. Kase,∗1 M. Kidera,∗1 K. Kobayashi,∗2 M. Komiyama,∗1 Y. Kotaka,∗2 H. Kuboki,∗1 K. Kumagai,∗1T. Maie,∗1 M. Nagase,∗1 T. Nakagawa,∗1 M. Nakamura,∗1 T. Nakamura,∗2 M. Nishida,∗2 M. Nishimura,∗2J. Ohnishi,∗1 H. Okuno,∗1 K. Ozeki,∗1 N. Sakamoto,∗1 J. Shibata,∗2 K. Suda,∗1 N. Tsukiori,∗2 A. Uchiyama,∗1S. Watanabe,∗1 T. Watanabe,∗1 Y. Watanabe,∗1 K. Yadomi,∗2 K. Yamada,∗1 and H. Yamazawa∗1
stream of the RRC and fRC, respectively, in Junefor the ﬁrst time. Owing to the gas strippers
and other continuous eﬀorts, a 345 MeV/nucleon124
Xe beam of 38 particle nA was provided to thebeam users with an availability as high as 91%.
c) Layer short of the RRC main-coil of the westsector magnet was ﬁxed by replacing it with anew one in August. Its soundness was conﬁrmed
in the MS of 50.5 MeV/nucleon-40 Ca accelerationin September.
d) The improvement of eﬃciency of injection to theRRC from RILAC2 was conﬁrmed when a sawtooth wave was used for the prebuncher instead ofa usual sine wave in the MS of 11 MeV/nucleon124
Xe acceleration in December. The acceleration
at harmonic numbers h = 12 and h = 18 insteadof the usual h = 9 was also tested for the future
upgrade of the RRC in the same MS. The obtained
data is now under analysis.

The yearly report on the operation of the four RIBF
ring cyclotrons RRC, fRC, IRC, and SRC, including
statistics of beam service time as well as developments
and troubles in the January–December 2013 period, ispresented.
The yearly operation status of the RIBF ring cyclotrons is summarized in Table 1. The medium-energy
beams accelerated by the RRC in the last stage wereused for the experiments and machine studies (MS) for1166 h in total. Similarly, the high-energy beams accelerated by the SRC in the last stage were used for
1646 h in total. The total operation time of RIBF ring
cyclotrons was 2812 h, of which only 304 h involved
temporary suspension due to the accelerator troubles.
We achieved a high beam availability of 94%. The
beam availability is deﬁned as the ratio of the actual
beam time after deduction of temporary suspension
time to the scheduled beam time.
The notable events in those operations are as follows(itemized ﬁgures correspond to those in Table 1):

For more details of those operations and others, referto Ref. 1.

a) The highest-energy beam ever of 400 MeV/nucleon
was successfully extracted from the SRC in the MS
using an 40 Ar beam in May.
b) Two gas strippers using He and air were usedin the double charge-exchanging process down-References
1) R. Koyama et al.: Proc. of PASJ10, Nagoya, Aichi, August 2013, SAP013, in press.

Table 1. Yearly operation results of the RIBF ring cyclotrons. For notable events a)–d), see text.
Last stage Preaccelerators Particle
EnergyExperimental
Intensity [particle nA]
cyclotron[MeV/nucleon]
courseRequested
Actual
40

RILAC

48

Ca
Ca

5886

Ni

Kr

238

RRC

RILAC2124

UXe
C

12AVF

Ar

4056
87

FeRb

50.5

RRC

63

E636

E3A

10.75

E2B

70

135
9590

E5A

D-roomE6

E5B
E2B/E5B

66

E6MS

143

SRC

RILAC-RRC-IRC
RILAC2-RRC-fRC-IRC

18250

Ar

400

O

40238
124

UXe

345

345

SAMURAIBigRIPSBigRIPS/ZDS/EURICA

0.0

100

10.4

102

0.0

100

156.0

156.6

28.5

1

38

12.0

12.7

0.0

10772

48.0

47.2

0.0

383

312.0

305.8

9.3

26

34.5

34.5

0.0

100

68.90.7142> 20087229MS

1211

10367

400
11410.1

144.0
24.0

24.0

52.0

157.5
24.0

24.052.0

980.0100a)105.391b)

137.5> 2038- 311 -100

108

137.5

RIKEN Nishina Center
SHI Accelerator Service Ltd.

d)

6.2

16@beam duty2%
1395

49.0

MS
>598

100

1166.1123.0

120.00.01061137.5
108.03130.0c)

199.0

48.0

231

1000.0

82

199.0

200

*

∗284.0294

Subtotal of high-energy experiment at new facility:
Total:∗184.0Temporary
Availability Notablesuspension [h][%]*
events200

Subtotal of medium-energy experiment at old facility:
AVF-RRC

Beam time [h]Scheduled Actual

100

132.0

33.7

660.0

700.3

109.9

1517.51646.1255.2

922655.02812.2

304.1

94

492.0

553.3

8289

Availability = (Actual beam time - Suspension)/(Scheduled beam time)x100