At around 150keV, If you know that the mass attenuation coefficient of lead is around 4 cm2 /g, and that its density is 11.34 g/cm3 : a) What is the half-value layer (HVL) of lead at this photon energy? b) How many sheets of HVL thickness you need to use in order to attenuate the X-ray beam at around 150keV to be lower than 10-3 of its incident intensity

At around 150keV, If you know that the mass attenuation coefficient of lead is around 4 cm2 /g, and that its density is 11.34 g/cm3 : a) What is the half-value layer (HVL) of lead at this photon energy? b) How many sheets of HVL thickness you need to use in order to attenuate the X-ray beam at around 150keV to be lower than 10-3 of its incident intensity