The exposure rate at 1 meter from a 1 Curie Cs-137 source is approximately?

The exposure rate at a distance of 1 meter from a 1 Curie source of Cs-137 is approximately 300 mR/hr. This value is grounded in the principles of radioactive decay and the specific emission characteristics of cesium-137.

Cs-137 is a common radioactive isotope used in radiological applications, particularly in medical and industrial settings. It emits gamma radiation, which is highly penetrating and can be measured as exposure in terms of milliroentgens per hour (mR/hr). The exposure rate from a radiation source decreases with distance according to the inverse square law, but at the standard reference distance of 1 meter, it has been established through experimental data and calculations that a 1 Curie source typically results in an exposure rate around the 300 mR/hr mark.

This value is important in practice as it helps radiological workers and health physicists understand the potential exposure that might occur near cesium-137 sources, enabling them to implement appropriate safety measures and protective equipment to minimize radiation exposure during handling or in situations where contamination could occur.