1. Institute of Physics, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
2. Comisión Chilena de Energía Nuclear, Santiago, Chile
3. Departamento de Ciencias Físicas, Universidad Andrés Bello, Republica 220, Santiago, Chile
4. Centre of Plasma Physics, Institute for Plasma Research, Sonapur, India
5. National Institute of Education, Nanyang Technological University, Singapore
6. Department of Electrical Engineering, Ruhr University Bochum, Bochum, Germany
7. Department of Physics, West Virginia University, Morgantown, West Virginia 26506, USA