| Paper |
Title |
Page |
| MOPO-12 |
Production of Multi-Charged Ions for Experimental Use at HIMAC
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92 |
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- A. Kitagawa, M. Muramatsu
NIRS, Chiba-shi
- S. Biri
ATOMKI, Debrecen
- A. G. Drentje
KVI, Groningen
- W. Takasugi, M. Wakaisami
AEC, Chiba
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Since 1994, heavy-ion radiotherapy using carbon ions is successfully carried out with the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). The maximum carbon ion energy is 400MeV/n. HIMAC is dedicated to radiotherapy, but it has as a second essential task to operate as users facility. In that scope it accelerates - during evening, night and weekend- many various ion species for basic experiments in biomedical science, physics, chemistry, material science, and so on. In order to serve all HIMAC users at best, the extension of the range of ion species is an important subject in ion source development at HIMAC. A PIG ion source mainly covers lighter ions from solid materials, while the 18GHz ECR ion source (called NIRS-HEC) is producing the heavier ions. Several developments on NIRS-HEC are now in progress. Various compounds are employed for the production of metallic ions by the MIVOC technique. In order to increase the beam intensity for heavier ions, additional microwave power is applied at a lower frequency by a traveling wave tube amplifier. Results of recent developments are reported.
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| TUCO-D03 |
Study of the Dependence of ECR Ion Current on Periodic Plasma Disturbance
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169 |
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- Dr. G. S. Taki, R. K. Bhandari, D. K. Chakraborty, P. R. Sarma
DAE/VECC, Calcutta
- A. G. Drentje
KVI, Groningen
- T. Nakagawa
RIKEN Nishina Center, Wako, Saitama
- P. K. Ray
Bengal Engineering and Science University, Howrah
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In a recent work we observed the existence of periodic current bursts from an ECR ion source when a biased disc is used for enhancing the extracted beam current. It was concluded that the current per burst in the source remains essentially constant. When the disc bias voltage is increased, the burst frequency increases, and so does the total current. Further it was seen that the current undergoes a jump at a fixed bias potential. The current jump has been found to be proportional to the charge state. The burst frequency also shows a correlated jump. However, in the case of protons a different trend is observed. As the bias potential is increased, at a particular potential value the current suddenly decreases. In this work we have studied the periodic bursts in the proton current in order to understand the difference in the behaviour of current jump in protons and heavy ions.
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