A person faces the possibility of receiving the following absorbed doses of radiation: 30 rad of X rays (RBE = 1), 5 rad of protons (RBE = 32), and 7 rad of alpha particles (RBE = 20). Which radiation will produce the least biological damage? a) the X-rays b) the alpha particles c) the protons d) They will produce the same damage.

A tumor is exposed to a beam of protons containing 2.6 × 1010 protons. If 25% of the beam energy is absorbed in a tumor of mass 1.25 kg, what is the dose equivalent in the tumor? Each proton has an energy of 52 MeV, and the RBE of this type of radiation is 32. a) 0.043 Sv b) 1.38 Sv c) 4.3 Sv d) 13.8 Sv e) 37 Sv

11. A 60 kg person accidentally ingests a small source of alpha particles (RBE=15). The activity of the source is 0.04 Ci, the half life of the source is 110 years, and each alpha particle emitted has an energy of 0.586MEV. It takes 12 hours for the alpha source to pass through the persons digestive system and exit the body. (a) How many alpha particles are absorbed by the person (you may assume that 100% of the alpha particles emitted by the source are absorbed by the person)? (b) How much energy is deposited in the person by the source (in J)? (c) What is the absorbed dose (in rad)? (d) What is the absorbed dose (in rem)?

The table gives the data the scientist obtained when she tested 1 kg of cooked A scientist has compared the vitamin content of food exposed to gamma radiation (c) with food that has not been exposed. chicken. Food not exposed to gamma radiation Food exposed to gamma radiation Vitamin Mass in milligrams Mass in milligrams B6 1.22 1.35 B12 21.00 28.00 E 3.30 2.15 Niacin 58.00 55.50 Riboflavin 2.10 2.25 Considering only this data, which one of the following is a correct conclusion? Put a tick (v) in the box next to your answer. Vitamin content is not affected by gamma radiation. Gamma radiation completely destroys some types of vitamin. Exposure increased the content of some types of vitamin. (1) (Total 6 marks)