Ⅱ-8. Accelerator

RIKEN Accel. Prog. Rep. 47 (2014)

NISHINA RIBF water-cooling system 2013
T. Maie,*1 K. Kusaka,*1 M. Ohtake,*1 Y. Watanabe,*1 E. Ikezawa,*1 M. Kase,*1 M. Oshima,*2 K. Kobayashi,*3 and J. Shibata*3
1.

Operation condition
In the fiscal year 2013, the Nishina and RIBF
water-cooling installation was operated for five and threemonths, respectively. These operation periods correspond tothe scheduled beam service time of RIBF, that is threemonths. In addition, Nishina’s cooling installation was used
not only for the full RIBF operation but also for the AVF
standalone and AVF + RRC operations. During FY2013,
there were no severe problems that caused beam service
interruption for the Nishina and RIBF cooling watersystems. In addition to the existing system, the newwater-cooling system was built only for the rare-RI ring,and its test operations also started in FY2013.
2.

Periodic maintenanceRoutine maintenance works as listed below areperformed during the scheduled summer and wintermaintenance periods of the RIBF accelerators.
1) Cleaning the cooling towers
2) Checking and overhauling the cooling-water pumps
3) Checking the control system of the RIBF
water-cooling system
4) Replacing some dated UPSs used for the control
system of the RIBF water-cooling system
5) Cleaning the plate heat exchangers
6) Checking and overhauling the air compressor

3.

Extension and improvement of the water-coolingsystem
A new beam transport line connecting theIntermediate-stage Ring Cyclotron (IRC) to the E5experimental vault is now under construction , aiming at
more efficient production of seaweed mutations induced byheavy-ion beams. Branches of cooling-water supply systemwere added to the existing system in order to supply coolingwater to the magnets and other devices used in this IRC-E5
beam line. The construction of a new experimental
apparatus, called SLOWRI, is also ongoing, and a newwater-cooling system for SLOWRI has also been
constructed. In addition, in order to raise the coolingcapability of the RF amplifiers used in IRC and theSuperconducting Ring Cyclotron (SRC), we plan to divide
the existing supply system commonly used for IRC andSRC into two independent supply systems dedicated to eachcyclotron. The present improvement will be effective forachieving high-power operation of the RF amplifiers.
4.

OthersBecause 30 years have passed since the construction of
the Nishina water-cooling system, its deterioration is now
remarkable. Performance degradation of the water-coolingsystem, especially in its temperature stability, is a possible
source of the unstable behavior in the RIBF accelerator
complex. Hence, the author recommended that thesuperannuated parts of the Nishina’s water-cooling systemshould be updated as soon as possible.
References1) T. Maie et al.: RIKEN Accel. Prog. Rep. 46 (2012).
2) M. Wada et al.: In this report.
3) Y. Yamaguchi et al.: In this report.

7) Replacing some superannuated hoses, joints, andvalves used in the system
8) Cleaning of the strainers and filters used in thedeionized water production system
9) Extending the sensing-wires of the water leakage
alarm to floors of new areas

RIKEN Nishina Center
Nippon Kucho Service Co., Ltd＊3
SHI Accelerator Service Co., Ltd＊1＊2- 159 -