1. Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
2. Physics, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
3. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
4. Princeton Plasma Physics Lab, Princeton University, Princeton, New Jersey 08540, USA
5. Center for Integrated Plasma Studies, University of Colorado Boulder, Boulder, Colorado 80309, USA