What Thickness Makes 0.3 A X-Rays Twice as Intense as 0.5 A X-Rays?

[so09er]

[SOLVED] Absorption of Photons question

Radiation of equal intensities of 0.3 A X-rays (Ua=0.3 1/mm) and 0.5 A x-rays (Ub=.72 1/mm) are incident on a material. Find the thickness of the material if, in the emerging radiation, the 0.3 A x-rays are twice as intense as the 0.5 A x-rays.

The only equation I have for this is I= Io e^(-Ux)

Thanks for any help on where to start or an equation to use.

 

[Mr.Brown]

just build up a system of equations relating the penetration deept of the radiation in the material and the extiction coefficents for both materials an set one intensity to half the other :)

 

[so09er]

Thanks for the help.