The 13th Symposium on Accelerator Science and Technology, Suita, Osaka, Japan, October 2001

Present Status of HIMAC
E. Takada, M. Torikoshi, Y. Sato, K. Noda, T. Murakami, A. Kitagawa, M. Suda, M. Muramatsu,
M. Yoshimoto, A. Sugiura, M. Kumada, K. Kono, M. Kanazawa, T. Honma, and S. Yamada,
Department of Accelerator Physics and Engineering, Research Center for Charged Particle Therapy,
National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, JapanandY. Sarro, C. Kobayashi, M. Yamamoto, T. Togashi, K. Narita, T. Kondo, H. Ogawa, H. Nakabushi*Accelerator Engineering Corporation, 2-13-1, Konakadai, lnage-ku, Chiba 263-0043, Japan(mailto: takada@nirs.go.jp)
transport lines, and an irradiation system for cancer
therapy and for relevant experiments.
It is the first ion-synchrotron built for medical treatment.
As such, priority of the machine operation anddevelopment efforts is focussed on reliable and stablebeam supply and improvement for matching into hospitaltype environment.
The number of patients treated by HIMAC carbon ion
has been increasing, more than tripled from the previous
report[l], as shown in Table I. A few words would be inorder on clinical result, although we need moreexperience in time and cases to establish the modality inan "evidence based" manner, and to advance to the phase
where it becomes covered by medical insurance orequivalent scheme.

Abstract
HIMAC has been supplying carbon beams for clinical
trial of charged particle therapy since 1994. It also
provides various ion beams from H to Xe forcollaborative study in physics, biology, and relevant fieldof research. Present status of HIMAC is described in thereport.

1. INTRODUCTION
HIMAC, Heavy Ion Medical Accelerator in Chiba, isan accelerator complex that consists of an injector system(ion-sources and linacs), two synchrotron rings (called theupper ring and the lower ring), high-energy beam

Table IHIMAC CARBON-ION CANCER-THERAPY PATIENTS ACCUMULATION ('94.6-'01.8)

Site (per Protocol)
Head & Neck

FY947

FY95
10Cent. Nerve
System68Lung

6Liver
Prostate GlandUterus
Bone & Soft Tissue
GeneralSkull BasePancreas
Eye-1112-9-9Rectum
Esophagus

FY961910---2427131813916--------Tongue2-

Annual Total

2183

1FY97
31
6171 191011131 30
61FYOO i FY01 Total
2920
176
15465

FY98 FY99
22 1j 38
79!'i

28
33
25 2~ 1730
i' 30
10 ' 11
1 19 6j 18
17 2i 32
42-

-

-

-

-

-

16445
2231!
'13!
25;
3~ 14
2
1'
1~'

30-

-

-

126

159

168

188

34-

-

-

20
1i 11i 16' 2' 7 1'
7l 5 222!-

~ 201

187 2
119 5144
6991 8138 15166422-23-

296

1042

151
33,1l8,Note: Number of "extra" (multiple) tumor target within the registered patients is shown in italic.

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The 13th Symposium on Accelerator Science and Technology, Suita, Osaka, Japan, October 2001

The local control rate in 2 years after treatment, and the
3-year survival rate are deduced from the subset oftabulated number of patients, and show considerably
better results. In Liver, e.g., local control is more than80 %. For further updated detail, see the relevant pages
ofhttp:llwww.nirs.go.jp.

2. ION SOURCES AND LINACS
There are two ECR~type and one PIG-type sources in
use at HIMAC. I OGHz ECR routinely provides C2+ beamfor treatment and other experiments, while 18GHz one
runs for Fe and heavier noble gasses. PIG covers Si, forexample. Recent topics of the sources are reported atICIS, held at Oakland, by the respective authors.[2]In Fig. I, the statistics of accelerated ion species in
HIMAC injector is shown for the last four and a half years.
Since April 1998, the Time-Sharing-Acceleration in theinjector linac system has been in operation, and theeffective beam supply time has been increased about 20 %.
TSA can provide three different beams to each destination,
two rings and a 6 MeVIA experiment course.

Annual Operation Hours for Various Ions (97.4-01.8:H
He

Full scale 4800hours for Cc
NeSi

Ar

IIFY97
DFY98

FeIll FY99

Kr•FYOO
OFY01

Xe
0120240

360

480

720

600

840

960

1080

1200

[hours]Fig. I. Acceleration Statistics of injector ofHIMAC. As indicated, data for FYOI are from April to August only.

3. SYNCHROTRONS AND HIGHENERGY BEAM TRANSPORTS
The synchrotron ring of HIMAC can accelerate ions ofqlm = 112 up to 800 MeVIA, although the clinical practice
is concentrated to carbon beams of290 to 400 MeVIA, atpresent. In Fig. 2, the annual operation hours of the lower
ring are shown with information on flat top energy. The
annual operation hours are about 5,500 hours, of which
major part is for therapy and relevant measurements. It
can be seen that carbon ion acceleration (for 290 and 400MeVIA) prevails more than 60% of the operational timeof a ring. It is to be noted that low energy operation sharereflects the activity for EC (electron cooling) installationin the ring.[3] Beam Profile Monitor using MCP isdeveloped and employed in the ring.[4]Since the last year, beam intensity for therapy irradiation
was elevated to, typically, 2.0xl09 particles per sec. inorder to expedite the irradiation time. This change wasmade possible by the development of "quasi-nondestructive" beam monitor at the end of transport lines forclinical ports, while the response of dose monitoring
system in the clinical port limits the possible use of evenhigher intensity. It is also instrumental in the change thatthe beam interlock system works excellently.[51-188-The 13th Symposium on Accelerator Science and Technology, Suita, Osaka, Japan, October 2001

Annual Operation Hours of HIMAC Synchrotron ( Lower Ring :Energy

FY97

1972

Planned5484h

1Dl1100-200

FY98

1902

1!11201-289

Planned
5436h

0290

FY99

1!11291-399

1790

Planned5340h

0400
1!11401-499

FYOO

1583
l!ll500-600

Planned5460h

1Dl1601-700

FY01(as of 8/31/01}.701-800

Planned
5508h

01200

3600

2400

4800

6000

[hours]Fig. 2. Acceleration Statistics in terms of accelerated beam energy from HIMAC synchrotron lower ring.

Although the collection of data is incomplete, machine
failure is controlled to a level of about 50 hours only foreach year, i.e., 1 %or less of the scheduled operation time.
RF and control (including PLC, VME and othercomputers) system are major source of the down. The lastand present years see more trouble in control domain thanthe previous years, due to both initial malfunctioning of a
new system and weared-out hardware of an old computer.

4. IRRADIATION SYSTEM AND
OTHER R&D ACTIVITY
In quest of confirming the irradiation range in thetreatment, the secondary beam line with clinicalirradiation facility is constructed.[6] To advance medical
application of accelerated beam, various· studies are being
carried out; a high field permanent magnet, a 7T wiggler
for medical use of SR, and a sheet beam profile monitor,
which are reported in the present symposium, by therespective authors.

ACKNOWLEDGEMENT
We would like to acknowledge Dr. F. Soga and themembers of Accelerator Phys. & Eng. Department, forcontinuous support and encouragement. We are gratefulto the members of AEC accelerator group for their effort
on operating, maintaining, and improving HIMAC, whichforms the basis of the present report.

REFERENCES[1] E. Takada, et al., "Present Status ofNIRS- HIMAC",
Proc. of 11th Symp. Ace. Sci. and Tech., Harima,
1997, pp.347-349[2] Following papers presented at ICIS will appear in
Rev. Sci. Instr., 2002. a)Y. Sato, et al., "Effects ofIon-Pumping in a Pulsed Penning Source", b)A.
Kitagawa, et al., "Study of the Extracted Beam andthe Radial Magnetic Field of ECR ion source atHIMAC", c)M. Sasaki, et al., "Metallic Ion Beam
Production at HIMAC", and d)M. Muramatsu, et al.,"Development of an ECR ion source for carbon
therapy".
[3] K. Noda, et al., "Electron Cooling Experiments atHIMAC," invited paper, in these proceedings.
T. Furukawa, et a!., "Beam alignment for electron
cooling at HIMAC", in these proceedings.
[4] T. Honma, T. Iwashima, et al., "A Non-destructive
Beam Profile Monitor Utilizing Charge-division
Method at HIMAC," in these proceedings.
[5] M. Katsumata, et al., "Beam Interlock System for
Medical Accelerator Complex HIMAC", in theseproceedings.
[6] A. Kitagawa, et al., "Radioactive Beam Project atHIMAC", presented at APAC01, Beijing.

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