Affiliation: | 1. Department of Physics, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile;2. Comisión Chilena de Energía Nuclear (CCHEN), Casila 188-D, Santiago, Chile;3. Plasma Technology Research Centre, Physics Department, University of Malaya, 50603 Kuala Lumpur, Malaysia |