Question

A thin film of nickel foil is to be used to prevent x-rays from reaching a sensitive specimen in a room where Cu x-rays were being used. The mass absorption coefficient of Ni measured using the Cu Ka line is 49.2 at the location where the specimen is stored. Calculate the minimum thickness of the Ni foil that must be used to protect the specimen if no more than 3.0% of the Cu x-radiation is allowed to reach the specimen. The density of Ni is 8.90 g/cm3

Answer 1