Status report on ECR ion sources at HIMAC

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

doi:10.1063/1.1690444

Cited by 6 publications

(1 citation statement)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Independently of the magnitude of the relative frequency difference (TCFH or TFFH) the importance of the fine tuning at least one of the two microwave frequencies was stated, since strong fluctuation of highly charged ions were obtained by slight tuning of the relative frequency difference [10,11]. In case of TCFH mode the optimal effect was obtained when the distance between the two resonant layers were close to the Larmor radius of the warm electrons [10].…”

Section: Introductionmentioning

confidence: 99%

Effect of the two-close-frequency heating to the extracted ion beam and to the X-ray flux emitted by the ECR plasma

et al. 2018

View full text Add to dashboard Cite

A: Multiple frequency heating has been used since the '90 in ECR ion sources as heating schemes able to improve current intensities especially for highly charged ions. More recently "Two Close Frequency Heating", where the frequency gap is comparable with the scale-length of the resonance, has been proposed, expected also to be sensitive to the relative waves' phase relationship. At ATOMKI -Debrecen a dedicated experiment has been carried out for exploring the effects of the combined frequencies and their relative phase-difference in an argon plasma. The second frequency was finely tuned between 13.6-14.6 GHz with respect to the first one (fixed 14.25 GHz). An optimal frequency gap (in terms of Ar 11+ /Ar 6+ beam currents ratios) has been experimentally found, in agreement with the theory; the optimal power balance (total RF power was 200 W) between the two frequencies has been determined empirically. A weak but clear effect of the relative phase shift has been observed. Each configuration has been characterized by a multidiagnostics setup: HPGe and SDD detectors were used for the X-rays, a RF probe was introduced inside the plasma chamber to detect the radio-emission from the plasma. K: Inspection with x-rays; Nuclear instruments and methods for hot plasma diagnostics; Plasma diagnostics -interferometry, spectroscopy and imaging 1Corresponding author.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of the two-close-frequency heating to the extracted ion beam and to the X-ray flux emitted by the ECR plasma

et al. 2018

View full text Add to dashboard Cite

show abstract

Medical application of radioactive nuclear beams at HIMAC

Kitagawa¹,

Furusawa²,

Kanai³

et al. 2006

Review of Scientific Instruments

View full text Add to dashboard Cite

The position of a short-lived positron emitting nuclei, such as 10 C and 11 C, can be precisely detected by measuring annihilation gamma-rays. By using the radioactive nuclear beam (RNB) of such nuclei, a particle range and an irradiated area can be observed in the human body. In order to improve the heavy ion cancer therapy, the RNB verification system has been developed at National Institute of Radiological Sciences (NIRS). The RNB has been obtained by the projectile fragmentation method from the relativistic high-energy heavy ion beams from the Heavy Ion Medical Accelerator in Chiba (HIMAC). The RNB system consists of a secondary beam course, a beam irradiation system, a patient's positioning system, and annihilation gamma-rays detectors.We measured the precise range by the positron camera detector and observed 3-D irradiate areas as PET images. Details of the system have been reported [1, 2].The instrumental accuracy obtained by experiments using the plastic phantom satisfied the requirement. However, the study of the biological and chemical process of the metabolism is important for the medical application. We determined the lifetime of the 10 C and 11 C injected into different organs of alive and dead rabbits. The lifetime in the alive rabbit has at least three components. These components are due to the very fast blood-stream in the blood vessel, the regional blood flow in the tissue, and unknown products which had the slow diffusion speed. In addition, The lifetimes for brains are faster than the muscle's ones.The microscopic process around the cell is also interested to study the biological effectiveness. The experiment of 9 C and 8 B beam is utilized for the research of the multi-hit cell. Because of the incident 8 B produces 8 Be, and then it emits two alpha particles. The range of these alpha particles in the water is about 10μm and it is equivalent as the size of normal cell. It means the cell is hit by three charged particles at the same time. We obtained the difference between 9 C and 12 C.[1] M. Kanazawa et al., Nucl. Phys. A 746, 393c (2004).[2] Y. Iseki et al., Phys. Med. Biol. 49, 1 (2004).

show abstract

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

Drentje

Muramatsu²,

Kitagawa³

2006

Review of Scientific Instruments

View full text Add to dashboard Cite

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 ͑a͒ to find the best condition for producing high beam currents of C 4+ ions, and ͑b͒ 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 C 5+ 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 ͑CD 4 gas͒ the C 5+ beam currents are about 10% higher than with regular methane ͑CH 4 gas͒. The "mixing-gas" ratio D ͑or H͒ to C can be decreased by choosing, e.g., butane gas; in this case the isotopic effect for C 5+ production is even stronger ͑Ͼ15% ͒. For production of C 4+ 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 C 4+ -ion currents than methane.

show abstract

Status report on ECR ion sources at HIMAC

Cited by 6 publications

References 4 publications

Effect of the two-close-frequency heating to the extracted ion beam and to the X-ray flux emitted by the ECR plasma

Effect of the two-close-frequency heating to the extracted ion beam and to the X-ray flux emitted by the ECR plasma

Medical application of radioactive nuclear beams at HIMAC

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

Contact Info

Product

Resources

About