Beta Identification

You are a health physicist and you find an unknown contaminant that proves to be a pure beta emitter. To try to identify the contaminant, you attempt to determine the maximum energy of the beta rays. You use a GM tube with a thin (0.1 mm, ?=2.7 g/cm^3) end window. You find that 1.74 mm stops all of the beta particles. The distance between the sample and the counter is 2 cm. a. What is the energy of the beta particle? b. What do you think the contaminant is?

Alpha & Beta Penetration

a) How much energy does an alpha particle require to penetrate the minimal protective epidermal layer of skin (thickness~7mg/cm^2)? b) How much energy does an beta particle require to penetrate the minimal protective epidermal layer of skin (thickness~7mg/cm^2)?

Gamma Flux and Absorption

A collimated beam of 200 keV gamma radiation delivers an incident energy flux of 2 J m^-2 s^-1 to a lead shield 1 g cm^-2 thick. a. What is the incident photon flux in photons cm^-2 s^-1? b. What is the rate of energy absorption in the shield in both erg g^-1 s^-1, J kg^-1 s^-1 and Gy s^-1

Mixed Energy Photon Beam

A collimated gamma ray beam consists of equal numbers of 0.1 MeV and 1.0 MeV photons. If the beam enters a 15 cm thick concrete shield, what is the relative portion of 1 MeV photons to 0.1 MeV photons in the emergent beam?

Radiation Heating

Assuming that the specific heat of the body is 1 cal g^-1 degrees C^-1, a) Plot the approximate temperature rise as a function of whole body dose ranging from 100 mGy to 10 Gy b) What absorbed dose would correspond to a potentially lethal heat body burden, assuming that a body temperature rise of 5 degrees C (normal body temperature ~ 37 degrees C) can be lethal?