Abstract
The present paper systematically studies the spontaneous fast reconnection mechanism in an initially forcefree current sheet in a wide range of plasma beta (β); in our previous work it was studied for a special case of β = 0.15. In each case, the evolution as well as the resulting structure of the fast reconnection is qualitatively similar to the one that was already reported for the case of β = 0.15. Quantitatively, the fast reconnection evolution becomes more rapid and drastic for the lower plasma beta. For the cases of very low plasma beta (β = 0.01 or 0.02), the plasma temperature is extremely enhanced to the value almost 1/β times larger than its initial value in the resulting fast reconnection jet and largescale plasmoid regions. Once the fast reconnection mechanism is ignited in a local spotlike region, its basic structure eventually established is sustained almost steadily, giving rise to the plasmoid swelling with time and propagating outwards. Accordingly, the characteristic reconnection regions, where plasma thermodynamic quantities are remarkably enhanced, rapidly expand in all (x, y, and z) directions in Alfven time scales, which may be responsible for the explosive expansion of large flares as well as for the distinct plasma heating observed in the solar corona.
This work was supported by the GrantinAids (21340142) from the Ministry of Education in Japan, Mitsubishi Foundation, RISH of Kyoto University, and SolarTerrestrial Environment Laboratory of Nagoya University.
I. INTRODUCTION
II. SIMULATION MODELING
A. Basic equations
B. Initialboundary conditions
III. RESULTS
A. Dependence on plasma beta
B. Fast reconnection structure for β = 0.01
IV. SUMMARY AND DISCUSSION
Key Topics
 Magnetic reconnection
 98.0
 Electrical resistivity
 21.0
 Plasma temperature
 17.0
 Plasma pressure
 15.0
 Magnetic fields
 13.0
Figures
Temporal variations of the reconnection electric field E_{z} (r = 0, t) measured at the origin r = 0 for the cases β = 0.01, 0.02, 0.5, and 1.0.
Temporal variations of the reconnection electric field E_{z} (r = 0, t) measured at the origin r = 0 for the cases β = 0.01, 0.02, 0.5, and 1.0.
Temporal variations of the outflow velocity u_{x} (x = 6, y = z = 0, t) measured at x = 6 on the x axis for the cases β = 0.01, 0.02, 0.5, and 1.0.
Temporal variations of the outflow velocity u_{x} (x = 6, y = z = 0, t) measured at x = 6 on the x axis for the cases β = 0.01, 0.02, 0.5, and 1.0.
Temporal variations of the outflow velocity u_{x} (x = 2, y = z = 0, t) measured at x = 2 on the x axis for the cases β = 0.01, 0.02, 0.5, and 1.0.
Temporal variations of the outflow velocity u_{x} (x = 2, y = z = 0, t) measured at x = 2 on the x axis for the cases β = 0.01, 0.02, 0.5, and 1.0.
(Color online) Distributions of the temperature T(x, y, z = 0) (contour interval of 0.08) and the flow vectors u in the z = 0 plane at times t = 36, 48, and 80 for the case of β = 0.02, where in (c) the plasmoid regions P and C are indicated.
(Color online) Distributions of the temperature T(x, y, z = 0) (contour interval of 0.08) and the flow vectors u in the z = 0 plane at times t = 36, 48, and 80 for the case of β = 0.02, where in (c) the plasmoid regions P and C are indicated.
(Color online) Distributions of the temperature T(x, y = 0, z) (contour interval of 0.08) and the flow vectors u in the y = 0 plane at times t = 36, 48, and 80 for the case of β = 0.02.
(Color online) Distributions of the temperature T(x, y = 0, z) (contour interval of 0.08) and the flow vectors u in the y = 0 plane at times t = 36, 48, and 80 for the case of β = 0.02.
(Color online) Magnetic field lines passing through the y axis and the reconnected field lines passing through the x axis (a) at time t = 100 for the case of β = 1.0 and (b) at t = 72 for the case of β = 0.01; in each case, the plasmoid center X_{C} on the x axis is indicated, and the plasma pressure distribution is shown in the y = 0 plane.
(Color online) Magnetic field lines passing through the y axis and the reconnected field lines passing through the x axis (a) at time t = 100 for the case of β = 1.0 and (b) at t = 72 for the case of β = 0.01; in each case, the plasmoid center X_{C} on the x axis is indicated, and the plasma pressure distribution is shown in the y = 0 plane.
Profiles of the plasma pressure P, plasma density ρ, magnetic field components B_{y} and B_{z} along the x axis (a) at time t = 100 for the case of β = 1.0 and (b) at t = 72 for the case of β = 0.01, where the characteristic x locations of the fast reconnection, X _{n} ,X _{p} , and X_{C} , are indicated.
Profiles of the plasma pressure P, plasma density ρ, magnetic field components B_{y} and B_{z} along the x axis (a) at time t = 100 for the case of β = 1.0 and (b) at t = 72 for the case of β = 0.01, where the characteristic x locations of the fast reconnection, X _{n} ,X _{p} , and X_{C} , are indicated.
Profiles of the plasma temperature T and the flow velocity u_{x} along the x axis at different times for the case of β = 0.01.
Profiles of the plasma temperature T and the flow velocity u_{x} along the x axis at different times for the case of β = 0.01.
(Color online) Distributions of (a) the temperature T(x, y, z = 0) (contour interval of 0.07), (b) the field component B_{z} (x, y, z = 0) (contour interval of 0.2) in the z = 0 plane, and (c) the B_{z} field (contour interval of 0.23) in the y = 0 plane at times t = 72 for the case of β = 0.01, where the flow velocity vectors u are also shown and the plasmoid center X_{C} is indicated.
(Color online) Distributions of (a) the temperature T(x, y, z = 0) (contour interval of 0.07), (b) the field component B_{z} (x, y, z = 0) (contour interval of 0.2) in the z = 0 plane, and (c) the B_{z} field (contour interval of 0.23) in the y = 0 plane at times t = 72 for the case of β = 0.01, where the flow velocity vectors u are also shown and the plasmoid center X_{C} is indicated.
(Color online) Distributions of the temperature T (contour interval of 0.07) at time t = 72 for the case of β = 0.01 in the (a) z = −4.5 plane and (b) z = 4.5 plane, where the flow velocity vectors u are shown and in (a) the plasmoid regions P and C are indicated.
(Color online) Distributions of the temperature T (contour interval of 0.07) at time t = 72 for the case of β = 0.01 in the (a) z = −4.5 plane and (b) z = 4.5 plane, where the flow velocity vectors u are shown and in (a) the plasmoid regions P and C are indicated.
Profiles of the plasma temperature T, the flow velocity u_{x} and the plasma density ρ at time t = 72 for the case of β = 0.01 along the (a) zdirectional line at x = 3.2 and y = 0 and (b) xdirectional line at y = 0 and z = −4.5.
Profiles of the plasma temperature T, the flow velocity u_{x} and the plasma density ρ at time t = 72 for the case of β = 0.01 along the (a) zdirectional line at x = 3.2 and y = 0 and (b) xdirectional line at y = 0 and z = −4.5.
(Color online) Distributions of (a) the temperature T (contour interval of 0.07), (b) the plasma pressure P (contour interval of 0.2), and (c) the field component B_{z} (contour interval of 0.2) in the x = 24 plane at time t = 72 for the case of β = 0.01, where in (a) the plasmoid regions P and C are indicated.
(Color online) Distributions of (a) the temperature T (contour interval of 0.07), (b) the plasma pressure P (contour interval of 0.2), and (c) the field component B_{z} (contour interval of 0.2) in the x = 24 plane at time t = 72 for the case of β = 0.01, where in (a) the plasmoid regions P and C are indicated.
(Color online) Distributions of the temperature T (contour interval of 0.07) in the y = 0.9 plane at times (a) t = 48 and (b) 72 for the case of β = 0.01, where the flow velocity vectors u are shown.
(Color online) Distributions of the temperature T (contour interval of 0.07) in the y = 0.9 plane at times (a) t = 48 and (b) 72 for the case of β = 0.01, where the flow velocity vectors u are shown.
Article metrics loading...
Full text loading...
Most read this month
Most cited this month










Electron, photon, and ion beams from the relativistic interaction of Petawatt laser pulses with solid targets
Stephen P. Hatchett, Curtis G. Brown, Thomas E. Cowan, Eugene A. Henry, Joy S. Johnson, Michael H. Key, Jeffrey A. Koch, A. Bruce Langdon, Barbara F. Lasinski, Richard W. Lee, Andrew J. Mackinnon, Deanna M. Pennington, Michael D. Perry, Thomas W. Phillips, Markus Roth, T. Craig Sangster, Mike S. Singh, Richard A. Snavely, Mark A. Stoyer, Scott C. Wilks and Kazuhito Yasuike

Commenting has been disabled for this content