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Start Over Author "Muramatsu, M" Journal review of scientific instruments
175 results on '"Muramatsu, M"'

2. Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)

Author

Kitagawa, A., primary, Drentje, A. G., additional, Fujita, T., additional, Muramatsu, M., additional, Fukushima, K., additional, Shiraishi, N., additional, Suzuki, T., additional, Takahashi, K., additional, Takasugi, W., additional, Biri, S., additional, Rácz, R., additional, Kato, Y., additional, Uchida, T., additional, and Yoshida, Y., additional

Published
2016
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5. Development of a compact ECR ion source for various ion production

Author

Muramatsu, M., primary, Hojo, S., additional, Iwata, Y., additional, Katagiri, K., additional, Sakamoto, Y., additional, Takahashi, N., additional, Sasaki, N., additional, Fukushima, K., additional, Takahashi, K., additional, Suzuki, T., additional, Sasano, T., additional, Uchida, T., additional, Yoshida, Y., additional, Hagino, S., additional, Nishiokada, T., additional, Kato, Y., additional, and Kitagawa, A., additional

Published
2016
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7. Multiply charged carbon-ion production for medical application

Author

Kitagawa, A., Muramatsu, M., Sasaki, N., Takasugi, W., Wakaisami, S., Biri, S., Drentje, A. G., Taksugi, W., and KVI - Center for Advanced Radiation Technology

Subjects
medicine.medical_specialty, Materials science, medicine.medical_treatment, Nuclear engineering, Brachytherapy, chemistry.chemical_element, Heavy Ion Radiotherapy, Sensitivity and Specificity, Ion, Radiotherapy, High-Energy, Plasma chamber, medicine, Medical physics, Instrumentation, Ions, Carbon ion, HIMAC, Equipment Design, Ion source, Carbon, Electronics, Medical, Equipment Failure Analysis, chemistry, Daily operation, ACCELERATOR, Beam (structure)
Abstract

Over 3000 cancer patients have already been treated by the heavy-ion medical accelerator in Chiba at the National Institute of Radiological Sciences since 1994. The clinical results have clearly verified the effectiveness and safety of heavy-ion radiotherapy. The most important result has been to establish that the carbon ion is one of the most effective radiations for radiotherapy. The ion source is required to realize a stable beam with the same conditions for daily operation. However, the deposition of carbon ions on the wall of the plasma chamber is normally unavoidable. This causes an "anti- wall-coating effect," i.e., a decreasing of the beam, especially for the higher charge-state ions due to the surface material of the wall. The ion source must be required to produce a sufficiently intense beam under the bad condition. Other problems were solved by improvements and maintenance, and thus we obtained enough reproducibility and stability along with decreased failures. We summarize our over 13 years of experience, and show the scope for further developments. (C)2008 Arnerican Institute of Physics.

Published
2008

15. Study on the beam transport from the Bio-Nano ECRIS

Author

Uchida, T., primary, Minezaki, H., additional, Oshima, K., additional, Racz, R., additional, Muramatsu, M., additional, Asaji, T., additional, Kitagawa, A., additional, Kato, Y., additional, Biri, S., additional, and Yoshida, Y., additional

Published
2012
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17. Status of ion sources at National Institute of Radiological Sciences

Author

Kitagawa, A., primary, Fujita, T., additional, Goto, A., additional, Hattori, T., additional, Hamano, T., additional, Hojo, S., additional, Honma, T., additional, Imaseki, H., additional, Katagiri, K., additional, Muramatsu, M., additional, Sakamoto, Y., additional, Sekiguchi, M., additional, Suda, M., additional, Sugiura, A., additional, and Suya, N., additional

Published
2012
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24. MIVOC method with temperature control

Author

Takasugi, W., primary, Wakaisami, M., additional, Sasaki, N., additional, Sakuma, T., additional, Yamamoto, M., additional, Kitagawa, A., additional, and Muramatsu, M., additional

Published
2010
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27. A singly charged ion source for radioactive 11C ion acceleration.

Author

Katagiri, K., Noda, A., Nagatsu, K., Nakao, M., Hojo, S., Muramatsu, M., Suzuki, K., Wakui, T., and Noda, K.

Subjects
SYNCHROTRONS, ION sources, RADIOACTIVE substances, HEAVY ion accelerators, NUCLEAR physics instruments, IONIZATION (Atomic physics)
Abstract

A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source. [ABSTRACT FROM AUTHOR]

Published
2016
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28. Medical application of radioactive nuclear beams at HIMAC

Author

Kitagawa, A., primary, Furusawa, Y., additional, Kanai, T., additional, Kanazawa, M., additional, Mizuno, H., additional, Muramatsu, M., additional, Sato, S., additional, Suda, M., additional, Tomitani, T., additional, Urakabe, E., additional, Yoshimoto, M., additional, Li, Q., additional, Wei, Z., additional, Hanawa, K., additional, Iseki, Y., additional, and Sato, K., additional

Published
2006
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30. Metallic ion beam production at HIMAC

Author

Sasaki, M., primary, Kitagawa, A., additional, Muramatsu, M., additional, Jincho, K., additional, Sasaki, N., additional, Sakuma, T., additional, Takasugi, W., additional, and Yamamoto, M., additional

Published
2002
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32. Effects of ion pumping in a pulsed Penning source

Author

Sato, Y., primary, Miyata, T., additional, Miyoshi, T., additional, Kitagawa, A., additional, Muramatsu, M., additional, Murakami, T., additional, Honma, T., additional, Yamamoto, M., additional, Ogawa, H., additional, and Yamada, S., additional

Published
2002
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34. Status of the HIMAC pulsed Penning source

Author

Miyata, T., primary, Sakamoto, H., additional, Yamamoto, M., additional, Okada, T., additional, Kobayasi, C., additional, Honda, Y., additional, Fujimoto, T., additional, Takasugi, W., additional, Yokoyama, T., additional, Kageyama, Y., additional, Fukusima, T., additional, Ogawa, H., additional, Fujiwara, H., additional, Muramatsu, M., additional, Kitagawa, A., additional, Murakami, T., additional, Yamada, S., additional, and Sato, Y., additional

Published
2000
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41. Status of ion sources for the Heavy Ion Medical Accelerator HIMAC

Author

Kitagawa, A., primary, Yamada, S., additional, Muramatsu, M., additional, Ogawa, H., additional, Sato, Y., additional, Torikoshi, M., additional, Yoshizawa, J., additional, Sekiguchi, M., additional, Hattori, T., additional, Honda, Y., additional, Kimura, T., additional, Kobayashi, C., additional, Matsushita, H., additional, Okada, T., additional, Sakamoto, H., additional, Shibuya, S., additional, Yamamoto, M., additional, and Sawada, K., additional

Published
1996
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42. Development of the National Institute of Radiological Sciences electron cyclotron resonance ion source for the heavy ion medical accelerator in Chiba

Author

Kitagawa, A., primary, Yamada, S., additional, Kohno, T., additional, Murakami, T., additional, Muramatsu, M., additional, Noda, K., additional, Ogawa, H., additional, Sato, Y., additional, Yamada, T., additional, Yoshizawa, J., additional, Fu, S., additional, Sekiguchi, M., additional, Ohshiro, Y., additional, Hattori, T., additional, Shibuya, S., additional, Matsushita, H., additional, Sawada, K., additional, and Morishita, O., additional

Published
1994
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43. Experiments with biased cylinder in electron cyclotron resonance ion source (plenary).

Author

Drentje, A. G., Kitagawa, A., Muramatsu, M., Ogawa, H., and Sakamoto, Y.

Subjects
ELECTRON cyclotron resonance sources, MAGNETIC fields, MAGNETIC flux, IONS, PLASMA gases, PHYSICS
Abstract

The shape of the magnetic field of an electron cyclotron resonance ion source (ECRIS) gives rise to different particle fluxes (losses) from the plasma to the end plates (mainly diffusion of electrons), and to the side walls (mainly ions). The electron fluxes to the injection end plate can be reduced by negatively biasing this plate (or so-called biased disk); this appeared to be successful to improve the output of highly charged ions (HCIs). In the present experiment it was demonstrated that by positively biasing the side walls, the HCI production can be improved as well. Electrons leaking from the ECRIS plasma to the side wall find their way easiest at the “pole” areas (of the hexapole magnet) because these are the areas where fieldlines pass the plasma chamber. A special construction was made to study the effect of biasing two different regions: (1) the areas between the six poles, and (2) the parts corresponding to the poles. Measurements show that method (2) gives better performance of the source. The relative improvement for the highest observed charge states is the best, and in absolute sense the application of the method is giving, e.g., a four times higher intensity for Ar11+ beams. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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44. Development of gas pulsing system for electron cyclotron resonance ion source.

Author

Hojo, S., Honma, T., Muramatsu, M., Sakamoto, Y., and Sugiura, A.

Subjects
ION sources, PERMANENT magnets, ELECTRON cyclotron resonance sources, HEAVY ion accelerators, RADIOACTIVE nuclear beams, POSITRON beams
Abstract

A gas-pulsing system for an electron cyclotron resonance ion source with all permanent magnets (Kei2 source) at NIRS has been developed and tested. The system consists of a small vessel (30 ml) to reserve CH4 gas and two fast solenoid valves that are installed at both sides of the vessel. They are connected to each other and to the Kei2 source by using a stainless-steel pipe (4 mm inner diameter), where the length of the pipe from the valve to the source is 60 cm and the conductance is 1.2 l/s. From the results of the test, almost 300 e μA for a pulsed 12C4+ beam was obtained at a Faraday cup in an extraction-beam channel with a pressure range of 4000 Pa in the vessel. At this time, the valve has an open time of 10 ms and the delay time between the valve open time and the application of microwave power is 100 ms. In experiments, the conversion efficiency for input CH4 molecules to the quantity of extracted 12C4+ ions in one beam pulse was found to be around 3% and the ratio of the total amount of the gas requirement was only 10% compared with the case of continuous gas provided in 3.3 s of repetition in HIMAC. [ABSTRACT FROM AUTHOR]

Published
2008
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45. Optimizing C4+ and C5+ beams of the Kei2 electron cyclotron resonance ion source using a special gas-mixing technique.

Author

Drentje, A. G., Muramatsu, M., and Kitagawa, A.

Subjects
*ELECTRON cyclotron resonance sources, *ION sources, *IONS, *ELECTRONS, *QUANTUM electrodynamics, *ISOTOPES, *NUCLIDES, *GASES, *PHYSICS
Abstract

With the prototype electron cyclotron resonance ion source for the next carbon therapy facility in Japan a series of measurements has been performed in order (a) to find the best condition for producing high beam currents of C4+ ions, and (b) to study the effect of “special” gas mixing by using a chemical compound as a feed gas. The effect would then appear as an increase in high charge state production in this case of C5+ ions. In “regular” gas-mixing experiments it is well known that an isotopic phenomenon occurs: a heavier isotope of the mixing gas is increasing the production of high charge states of the beam gas ions. A similar isotopic effect has been found in the present experiment: with deuterated methane (CD4 gas) the C5+ beam currents are about 10% higher than with regular methane (CH4 gas). The “mixing-gas” ratio D (or H) to C can be decreased by choosing, e.g., butane gas; in this case the isotopic effect for C5+ production is even stronger (>15%). For production of C4+ ions the isotopic effect appears to be absent. Clearly this is related to the much easier production. It turns out that the relative amount of carbon is much more important: butane gives about 10% higher C4+-ion currents than methane. [ABSTRACT FROM AUTHOR]

Published
2006
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46. Fullerenes in electron cyclotron resonance ion sources.

Author

Biri, S., Fekete, É., Kitagawa, A., Muramatsu, M., Jánossy, A., and Pálinkás, J.

Subjects
ELECTRON cyclotron resonance sources, ION sources, IONS, MULTIPLY charged ions, INDUSTRIAL applications of electron beams, SOLENOID magnetic fields, FULLERENES, PLASMA electrodynamics, QUANTUM electrodynamics
Abstract

Fullerene plasmas and beams have been produced in our electron cyclotron resonance ion sources (ECRIS) originally designed for other purposes. The ATOMKI-ECRIS is a traditional ion source with solenoid mirror coils to generate highly charged ions. The variable frequencies NIRS-KEI-1 and NIRS-KEI-2 are ECR ion sources built from permanent magnets and specialized for the production of carbon beams. The paper summarizes the experiments and results obtained by these facilities with fullerenes. Continuous effort has been made to get the highest C60 beam intensities. Surprisingly, the best result was obtained by moving the C60 oven deep inside the plasma chamber, very close to the resonance zone. Record intensity singly and doubly charged fullerene beams were obtained (600 and 1600 nA, respectively) at lower C60 material consumption. Fullerene derivatives were also produced. We mixed fullerenes with other plasmas (N, Fe) with the aim of making new materials. Nitrogen encapsulated fullerenes (mass: 720+14=734) were successfully produced. In the case of iron, two methods (ferrocene, oven) were tested. Molecules with mass of 720+56=776 were detected in the extracted beam spectra. [ABSTRACT FROM AUTHOR]

Published
2006
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47. rf modes and plasma formation of electron cyclotron resonance ion source.

Author

Hayashizaki, N., Hattori, T., and Muramatsu, M.

Subjects
ELECTRON cyclotron resonance sources, FREQUENCY spectra, PLASMA frequencies, RADIO frequency, ION sources, CAVITY resonators, MICROWAVE devices, RADIO wave propagation, ELECTRIC fields
Abstract

The plasma chamber of electron cyclotron resonance (ECR) ion sources may be considered as a cavity resonator in radio-frequency (rf) technology. The microwave frequency then has to be tuned to the resonant frequency of a preferable mode. In order to produce ions with higher charge state, the rf characteristics of the plasma chamber should be investigated. As the first study, the rf simulation and the experimental measurement were carried out for a permanent magnet ECR ion source, which was developed at Tokyo Institute of Technology (TokyoTech). The frequency spectrum of microwave power transmission was measured to check the resonance points of the plasma chamber. The mode analysis was performed by a theoretical calculation and with a three-dimensional simulation code. These results and the effect of the electric-field distribution on ECR plasma will be presented. [ABSTRACT FROM AUTHOR]

Published
2006
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48. Low-energy ion decelerator for an external injection line at the NIRS-930 cyclotron.

Author

Honma, T., Hojo, S., Sakamoto, Y., Muramatsu, M., Miyahara, N., Okada, T., Komatsu, K., and Yamada, S.

Subjects
PHYSICS research, ACCELERATION (Mechanics), PARTICLE accelerators, CYCLOTRONS, ION bombardment, ION sources, RESONANCE, ELECTRON accelerators, ELECTRIC fields
Abstract

A low-energy ion decelerator for the acceleration-deceleration system has been designed and installed in the beam-injection line of the NIRS-930 cyclotron in an attempt to increase the beam intensity from the cyclotron. With this acceleration-deceleration system, the beam intensity of 12C4+ ions at the cyclotron exit has been increased by about five times. The system has an advantage in that it allows us to extract a high-current ion beam from an electron cyclotron resonance ion source because, independently of the injection-energy matching to the cyclotron, a large potential difference can be applied between the source and the extractor. The voltage applied to the extractor is about -12 kV, which is reduced to the ground potential by the decelerator. The electric field distributions in the deceleration system were carefully designed using a three-dimensional field simulator. Design studies of the decelerator as well as the result of a beam test are presented. [ABSTRACT FROM AUTHOR]

Published
2006
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49. Status report on ECR ion sources at HIMAC.

Author

Kitagawa, A., Muramatsu, M., Sasaki, M., Yamada, S., Sakuma, T., Sasaki, N., Takahashi, H., Takasugi, W., Yamamoto, M., Biri, S., Sudlitz, K., and Drentje, A. G.

Subjects
*HEAVY ion accelerators, *CANCER treatment, *RADIOTHERAPY, *ION sources, *ION bombardment, *CANCER radiotherapy
Abstract

The Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS) is the first heavy-ion accelerator complex dedicated to cancer therapy. Over 1600 patients have already been treated with 140–400 MeV/amu carbon beams since 1994. The production of carbon ions for medical applications has been established. It is quite obvious from our experiences that the ECR ion source is an extremely suitable type of ion source for this purpose. An 18 GHz ECR ion source is mainly operated to offer various heavy-ion beams for basic experiments of biomedical science, physics, chemistry, etc. The results of recent developments, a thermal-controlled MIVOC system, and an electron bombardment evaporator are also reported. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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50. Compact ECR ion source with permanent magnets for carbon therapy.

Author

Muramatsu, M., Kitagawa, A., Sakamoto, Y., Sato, Y., Yamada, S., Ogawa, H., Drentje, A. G., Biri, S., and Yoshida, Y.

Subjects
*ION sources, *IONS, *NUCLEAR physics instruments, *ELECTRON cyclotron resonance sources, *PERMANENT magnets, *MAGNETS, *NUCLEAR physics, *PHYSICS
Abstract

Ion sources for the medical facilities should have the following characteristics of easy maintenance, low electric power, good stability, and long operation time without trouble (1 year or longer). For this, a 10 GHz compact electron cyclotron resonance ion source (ECRIS) with all permanent magnets was developed. The beam intensity and stability for C4+ were 280 e μA and better than 6% during 20 h with no adjustment of any source parameters. These results were acceptable for the medical requirements. Recently, many plans were proposed to construct the next generation cancer treatment facility. For such a facility we have designed an all permanent magnet ECRIS, in which a high magnetic field is chosen for increasing the beam intensity. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas injection side, while the minimum B strength is 0.25 T. The source has a diameter of 32 cm and a length of 29.5 cm. Details of the design of this source and its background are described in this article. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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