Safety aspects of particle accelerators

Particle accelerators are used to accelerate charged particles such as protons, alpha particles, heavy ions, electron, positrons etc. with the ultimate aim of using them for research, industrial or medical purposes. The process of acceleration can be different depending upon the particle being accelerated, the final energy envisaged and its utilization. In the earlier days, the interest was to bombard a suitable target by energetic projectiles obtained by such machines and look for signature emissions using detectors. The technique is still applied with increasing sophistication and size but many machines are now also being built to utilize the accelerated particles directly or the secondary radiation it produces. The safety aspects of a particle accelerator can be due to the presence of ionizing radiation or nonionizing radiation and toxic or other hazardous gases. (author)