system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which of the following is the most penetration beam?
assistant
The correct answer is  The order of penetration power is ? rays> electrons> a paicles. Here the 18MeV photon will have more energy than 8MeV photon. Ref: Essentials of Environmental Health, By Robe H. Friis, 2011, Page 191