Hello, 1. The problem statement, all variables and given/known data We use an accelerator to uniformly implant electrons in a block of lucite, its surface is 25 cm², thickness 12mm. The current of the electron beam is 0,1 µA and the implantation takes 1s. The electrons are "trapped" in a layer of uniform density of 2mm thickness whose center is at 6 mm of the block surface. The two large surfaces have same potential V=0. - Find the polarization charge density ρp in each of the three regions of the block. - Find the polarization charge density of surface σp over the two large surfaces of the block. 2. Relevant equations ρ= ∇. D D=εoE+P P=εo XeE σp= P.n^ 3. The attempt at a solution I'd say that outside the layer where the electrons are ρp =0 And I am really really stuck .. I have to return this before the end of tomorow, and i'm not getting any of this.. I've read the course notes a hundred times Thanks !