Regular Articles

Full Text / References

Development of High-Power-Density Ion Beam System with High-Repetition Pulse Operation

Hajime SAKAKITA, Satoru KIYAMA, Haruhisa KOGUCHI, Yoichi HIRANO, Toshio SHIMADA, Masayuki TOKITANI¹⁾, Naoaki YOSHIDA²⁾ and Kazutoshi TOKUNAGA²⁾

National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568, Japan

1)

National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan

2)

Kyushu University, 6-1 Kasuga-kouen, Kasuga 816-8580, Japan

(Received 14 January 2010 / Accepted 22 April 2010 / Published 10 December 2010)

Abstract

A high-power-density ion beam system with high-repetition pulses was successfully developed. In the ITER (International Thermonuclear Experimental Reactor), it is anticipated that an intermittent thermal flux, due to the edge localized mode (ELM), to the plasma facing materials causes severe damage of the mechanical properties. Therefore, it is very important to study the effect of ELM phenomena. We already developed an ion beam system with a power density as high as ∼1 GW/m² around the focal point of the beam. In order to imitate the intermittent high-power-density pulsed flux, we modified the beam operation method and part of the acceleration power supply. A pulsed helium ion beam with the beam width of 2 ms and 4 ms intervals between pulses was successfully extracted. In this case, beam energy, current and power were ∼22 keV, ∼40 A, and ∼0.88 MW, respectively. This high-repetition pulsed helium ion beam with high power density (∼300 MW/m² ) was irradiated to a tungsten material. It was found that this repetitive short-pulse irradiation caused less surface damage compared with long-pulse irradiation, even when the total amount of irradiation fluence (1.5× 10²² particles/m²) was the same for each condition. This would provide important data for the design of ITER diverter.

Copyright (c) 2010 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

high-power-density ion beam, high-repetition pulsed ion beam, ITER, edge localized mode (ELM), ELM simulator, plasma wall interaction, pulse beam irradiation, nanostructure

DOI: 10.1585/pfr.5.S2105

Full Text

PDF format (909Kbytes)

References

• [1] D. Nishijima et al., Jpn. J. Appl. Phys. 44, 380 (2005).
• [2] K. Tokunaga et al., J. Nucl. Mater. 329-333, 757 (2004).
• [3] M. Tokitani et al., J. Nucl. Mater. 337-339, 937 (2005).
• [4] A. Ebihara et al., J. Nucl. Mater. 363-365, 1195 (2007).
• [5] H. Sakakita et al., Proc. 32nd Eur. Phys. Soc. Conf. on Plasma Phys., Tarragona, P4-109 (2005).
• [6] H. Sakakita et al., Proc. 21st IAEA Fusion Energy Conf., Chengdu, FT/P5-2, 1 (2006).
• [7] H. Koguchi et al., Proc. 22nd IAEA Fusion Energy Conf., Geneva, EX/C14, 1 (2008).
• [8] M. Nishikawa et al., Fusion Eng. Des. 16, 351 (1991).
• [9] H. Sakakita et al., Jpn. J. Appl. Phys. 45, 8531 (2006).
• [10] H. Sakakita et al., Proc. 33rd Eur. Phys. Soc. Conf. on Plasma Phys., Roma, P1-115 (2006).
• [11] M. Tokitani et al., Plasma Fusion Res. 5, 012-1 (2010).
• [12] M. Kuriyama et al., JAERI Reports, JAERI-M87, 169 (1987) [in Japanese].
• [13] H. Sakakita et al., J. Plasma Fusion Res. SERIES 8, 674 (2009).
• [14] D. Nishijima et al., J. Plasma Fusion Res. 81, 703 (2005).

This paper may be cited as follows:

Hajime SAKAKITA, Satoru KIYAMA, Haruhisa KOGUCHI, Yoichi HIRANO, Toshio SHIMADA, Masayuki TOKITANI, Naoaki YOSHIDA and Kazutoshi TOKUNAGA, Plasma Fusion Res. 5, S2105 (2010).