1. Department of Physics and Basic Sciences, Faculty of Engineering Technology , Al-Balqa Applied University , P.O. Box 2587 , Amman , , Jordan
2. Department of Physics, Faculty of Science , Al-Balqa Applied University , P.O. Box 2587 , Amman , , Jordan
3. Department of Physics , the University of Jordan , P.O. Box 13535 , Amman , , Jordan