JAEA-Review-2010-065.pdf:15.99MB - 日本原子力研究開発機構

Operation of the AVF Cyclotron
T. Nara a) , I. Ishibori a) , S. Kurashima a) , K. Yoshida a) , T. Yuyama a) , T. Ishizaka a) ,
S. Okumura a) , N. Miyawaki a) , H. Kashiwagi a) , Y. Yuri a) , W. Yokota a) , K. Akaiwa b) ,
To. Yoshida b) , S. Ishiro b) , Tu. Yoshida b) , S. Kanou b) , A. Ihara b) , K. Takano b) and T. Saitoh b)
a) Department of Advanced Radiation Technology, TARRI, JAEA, b) Beam Operation Service, Co., Ltd.
Operation
The AVF cyclotron was steadily operated throughout
fiscal 2009 and supplied various ion beams for research
experiments. The cumulative operation time was 59,535
hours and the total number of experiments was 8,125 from
the first beam extraction in 1991 to March 2010.
Table 1 shows the statistics of the cyclotron operation of
fiscal 2009. The total operation time amounted to 3,148.3
hours, and monthly operation times are shown in Fig. 1.
The percentages of operation time of the year used for
regular experiments, joint-use, the innovation program,
beam tuning, and beam development are 66.9%, 8.9%, 2.4%,
19.7%, and 2.1%, respectively. The number of machine
troubles was 130. The only trouble that led to cancellation
of experiments was a breakdown of a power supply of the
cyclotron RF system.
Table 1 Statistics for cyclotron operation in fiscal 2009.
Beam service time 2,461.8 h
Machine tuning 620.9 h
Beam development 65.6 h
Total operation time 3,148.3 h
Change of particle and/or energy 238 times
Change of beam course 309 times
Change of harmonic number 56 times
The number of experiments 633
Experiment cancelled due to machine trouble 2(8.5h)
Operation Time (h)
450
400
350
300
250
200
150
100
50
5-02
0
Experiments
Beam development
Innovation
Joint-use
Tuning
Maintenance
Maintenance of
power supplies
Maintenance
4 5 6 7 8 9 10 11 12 1 2 3
Fig. 1 Monthly operation time in fiscal 2009.
The multi-cusp ion source is used to produce H + and D +
ions. For production of ions heavier than Helium, two
ECR ion sources are used alternatively. Table 2 shows the
operation time of each ion source. Fractional distribution
of major ions used for experiments is shown in Fig. 2. The
tendencies of the statistics are similar to those of the past
years.
JAEA-Review 2010-065
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Table 2 Operation times of ion sources.
Ion source Operation time(h) Ratio(%)
Multi-cusp 1,041.0 30.2
ECR (OCTOPUS) 983.6 28.6
ECR(HYPERNANOGAN) 1,418.9 41.2
Metal
3.5%
Xe
5.1%
Kr
0.6%
Coctail
14.4%
Others
1.2%
Ar Ne
5.8% 10.8% C
O 17.4%
2.1%
H
30.8%
He
8.0%
D
0.4%
Fig. 2 Ion species used for experiments in fiscal 2009.
Maintenance
The regular yearly overhaul and maintenance were
carried out. The major items were as follows:
1) Correction of the reference positions of some beam
probes, the inflector, etc. 2) Replace of the sequence
controllers for safety interlock system. 3) Inspection of the
RF system and evaluation of its characteristics. 4) Change
of lubricating oil for about 50 rotary pumps. 5) Inspection
of the beam scanner power supplies. 6) Routine
maintenance of the power supplies. 7) Improvement of the
controller of the beam attenuator.
Technical Development
The new beam acceleration tests were carried out for
12 MeV D + , 25 MeV H + , 490 MeV 192 Os 30+ and 98 MeV
28 Si 5+ , and they are ready for use in experiments.
A measurement system of a large-area uniform beam by
means of beam-induced fluorescence is being developed in
order to evaluate beam characteristics such as beam shape,
size and uniformity in real time. Development of a
technique for reducing the changing time of the magnetic
field of the cyclotron is also in progress for quick change of
ion species and beam energy. The details of those
technical developments are described elsewhere in this
annual report.