Numerical simulations have consistently shown that the reconnection rate in certain collisionless regimes can be fast, of the order of , where and are the Alfvén speed and the reconnecting magnetic field upstream of the ion diffusion region. This particular value has been reported in myriad numerical simulations under disparate conditions. However, despite decades of research, the reasons underpinning this specific value remain mysterious. Here, we present an overview of this problem and discuss the conditions under which the '0.1 value' is attained. Furthermore, we explain why this problem should be interpreted in terms of the ion diffusion region length.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Astrophysical plasmas
- plasma nonlinear phenomena
- space plasma physics