7 Synthesis of Polyaniline HCl Pallets and Films Nanocomposites by Radiation Polymerization M. A. Ali Omer 1, 2* , E. Saion 2 , M. E. M. Gar Elnabi 1 and Kh. Mohd. Dahlan 3 1 Sudan University of Science and Technology, College of Medical Radiologic Science, 2 Department of Physics, Faculty of Science, University Putra Malaysia, Selangor, 3 Nuclear Agency Malaysia (NAM), Bangi, Selangor, 1 Sudan 2,3 Malaysia 1. Introduction The sources of radiation are so varies, some of them are natural and others are man-made. Also the types of radiation can be categorized according to their wave length or energy or even to the ability of ionizing the media. Non-ionizing radiation is electromagnetic radiation that does not have sufficient energy to remove the electrons from the outer shell of the atom. Types of non-ionizing radiation are: ultra violet (U/V), Visible light, infrared (IR), microwave (radio and television), and extremely low frequency (ELF, or as they called EMF or ELF-EMF). Non-ionizing radiations produced by a wide variety of sources at homes and in the workplaces, form lasers to power lines, tanning beds to household appliances, cellular phones to home radios (Smith F. A. 2000). Ionizing Radiation: refer to the types of radiation that has capability to ionize the media directly or indirectly such as X-ray, γ-ray and neutron. 2. Natural sources The natural sources represented in the following: i. Cosmic radiation: represent the radiation comes from outside our solar system as positively charged ions (protons, irons, nuclei, helium…) which are interact with atmospheric layer (air) around the ground to produce secondary radiation as (X-ray, Muons, Protons, Alpha particles, Pions, Electrons and Neutrons). ii. External terrestrial sources: these represent the radioactive materials, which are found naturally in the earth crust, rocks, water, air and vegetation. The major radio-nuclides found in the earth crust are (Potassium-40, Uranium-235, and Thorium-210). 3. Artificial sources The main sources of manmade radiation that expose the public are from (Medical Procedures, as in diagnostic X-ray, radiation therapy, nuclear medicine and sterilization).