Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 50 (2017)

RILAC operation
E. Ikezawa,*1 T. Ohki,*2 M. Kase,*1 T. Nakagawa,*1 N. Sakamoto,*1 H. Okuno,*1 N. Fukunishi,*1M. Komiyama,*1 A. Uchiyama,*1 T. Maie,*1 M. Nagase,*1 M. Fujimaki,*1 T. Watanabe,*1 H. Hasebe,*1H. Imao,*1 K. Ozeki,*1 K. Suda,*1 Y. Higurashi,*1 K. Yamada,*1 Y. Watanabe,*1 S. Watanabe,*1 M. Kidera,*1T. Nagatomo,*1 H. Yamauchi,*2 K. Oyamada,*2 M. Tamura,*2 A. Yusa,*2 K. Kaneko,*2 and O. Kamigaito*1
The RIKEN heavy-ion linac (RILAC) has operated
steadily throughout the reporting period and has supplied
various ion beams for different experiments. Some statistics
regarding the RILAC operation from January 1 toDecember 31, 2016 are presented in Table 1. The total beamservice time of the RILAC accounted for 89.7% of its
operation time. The two operation modes of the RILAC, thestandalone mode and the injection mode, in which the beam
is injected into the RIKEN Ring Cyclotron (RRC),
accounted for 77.5% and 22.5% of the total beam service
time of the RILAC, respectively. For experiments, a2.675-MeV/nucleon 48Ca-ion beam accelerated by theRILAC was injected into the RRC from November 12 toDecember 6. Table 2 lists the beam service times in thestandalone mode of the RILAC allotted to the e2 and e3
beam courses in target room no. 1 in 2016. The e2 beamcourse was used in experiments with the GARIS2. The e3
beam course was used in experiments with the GARIS.
Table 3 lists the operation time of the 18-GHz ECR ion
source in 2016.
We performed the following improvements and overhauls
during the reporting period.
1) In the RF systems, DC high-voltage power supplies
were subjected to annual inspection. The major
components with mechanical parts were subjected tosimple inspection.
2) The water pumpsfor the RFQ, RILAC, and CSM weresubjected to annual inspection. All cooling towers weresubjected to monthly inspection and annual cleaning.
3) All the turbomolecular pumps were subjected to annualinspection. Cryogenic pumps used for the RILAC no. 3,RILAC no. 4, RILAC no. 6, CSM A5, and CSM A6cavities were overhauled.
Table 1. Statistics of RILAC operation from January 1 toDecember 31, 2016.

Operation time of RILAC

䠆1
䠆2

We faced the following mechanical problems during thereporting period.
1) Water was found to have splashed in the end drift tubeof the CSM A3-A6 cavities because of leakage fromeach cooling pipe. We repaired the pipes with a repair
material as a stopgap measure. In addition, the faulty
part of the end drift tube of the CSM A4 cavity wasreplaced.
2) A section of the air-pressure pipe for the contact fingersof the rf shorting plate in the RILAC no. 4 and theRILAC no. 6 cavities had a vacuum leak because of adeterioratedO-ring. We replaced it with a new one.
Table 2. Beam service time of the standalone RILAC
allotted to each beam course in target room no.
1 in 2016.
Beam course

Total time (h)%e21674.6

59.2

e31154.6

40.8

Total

2829.2100.0

Table 3. Operation time of the 18-GHz ECR ion source in2016.
Ion

MassCharge state

Total time (h)He4224.0

O185,6300.9

Ne227528.0

Na237416.2

Mg247129.2

Ar3610216.6Ar

40

9,11207.2

4127.8 hCa4010192.0

Mechanical problems

64.9 hCa

48

10,111959.9

Standalone RILAC

2868.0 hTi

5011329.7

Injection into RRC

834.3 hV

5111216.0Ni5813120.0

Total beam service time of RILAC

3702.3 hKr861884.6Au

197

2624.0U

2383582.1Total

RIKEN Nishina Center
SHI Accelerator Service Ltd.
- 281 -4830.4