Nickel x-rays are to be generated inside a container, with the x-rays being emitted from the container through only a small slot. Design a container that will ensure that no more than 0.01% of the Ka nickel x-rays escape through the rest of the container walls, yet 95% of the Ka nickel x-rays pass through a thin window covering the slot. The following data give the mass absorption coefficients of several metals for nickel K_α x-rays. The mass absorption coefficient α_m is ayr, where a is the linear mass absorption coefficient and ρ is the density of the filter material. Nickel x-rays are to be generated inside a container, with the x-rays being emitted from the container through only a small slot. Design a container that will ensure that no more than 0.01% of the Ka nickel x-rays escape through the rest of the container walls, yet 95% of the K_α nickel x-rays pass through a thin window covering the slot. The following data give the mass absorption coefficients of several metals for nickel K_α x-rays. The mass absorption coefficient am is ayr, where a is the linear mass absorption coefficient and ρ is the density of the filter material.