Regular Articles

Full Text / References

Multi-Wavelength Imaging of Solar Plasma - High-Beta Disruption Model of Solar Flares -

Kiyoto SHIBASAKI

Nobeyama Solar Radio Observatory, Minamisaku, Nagano 384-1305, Japan

(Received 4 January 2007 / Accepted 27 April 2007 / Published 20 November 2007)

Abstract

Solar atmosphere is filled with plasma and magnetic field. Activities in the atmosphere are due to plasma instabilities in the magnetic field. To understand the physical mechanisms of activities / instabilities, it is necessary to know the physical conditions of magnetized plasma, such as temperature, density, magnetic field, and their spatial structures and temporal developments. Multi-wavelength imaging is essential for this purpose. Imaging observations of the Sun at microwave, X-ray, EUV and optical ranges are routinely going on. Due to free exchange of original data among solar physics and related field communities, we can easily combine images covering wide range of spectrum. Even under such circumstances, we still do not understand the cause of activities in the solar atmosphere well. The current standard model of solar activities is based on magnetic reconnection: release of stored magnetic energy by reconnection is the cause of solar activities on the Sun such as solar flares. However, recent X-ray, EUV and microwave observations with high spatial and temporal resolution show that dense plasma is involved in activities from the beginning. Based on these observations, I propose a high-beta model of solar activities, which is very similar to high-beta disruptions in magnetically confined fusion experiments.

Copyright (c) 2007 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

solar flare, solar activity, solar corona, high-beta plasma, ballooning instability, solar plasma imaging

DOI: 10.1585/pfr.2.S1012

Full Text

PDF format (1.7Mbytes)

References

• [1] L. Golub and J.M. Pasachoff, The Solar Corona (Cambridge University Press, 1997).
• [2] S. Tsuneta et al., PASJ 44, L63 (1992).
• [3] S. Masuda et al., Nature 371, 495 (1994).
• [4] D. Alexander et al., ApJL 494, L235 (1998).
• [5] B.N. Handy et al., Solar Phys. 187, 229 (1999).
• [6] H. Nakajima et al., Proc. IEEE 82, 705 (1994).
• [7] W.K.H. Panofsky and M. Phillips Classical Electricity and Magnetism (Addison-Wesley Pub. Co. Inc., Cambridge, Mass, 1961).
• [8] E.N. Parker, ApJ 128, 664 (1958).
• [9] Y. Nagayama et al., Phys. Rev. Lett. 69, 2376 (1992).
• [10] W. Park et al., Phys. Rev. Lett. 75, 1763 (1995).
• [11] K. Shibasaki, ApJ 557, 326 (2001).
• [12] A. Rowx et al., J. Geophys. Res. 96, 17697 (1991).

This paper may be cited as follows:

Kiyoto SHIBASAKI, Plasma Fusion Res. 2, S1012 (2007).