Projected ranges and effective stopping powers of electrons with energy between 20 eV and 10 keV

Experimental projected ranges of electrons between 20 eV and 10 keV have been correlated by a simple scaling factor to yield 'best-fit' expressions applicable to all media. Extrapolated ranges, R ex (in mu g cm -2 ) may be determined from the expressions given. From an analysis of the transmission curves, the following relation between median or mean projected ranges and the extrapolated ranges is obtained: R 50 =(0.3655+or-0l05) R ex 1.024 , 20 eV<or=E<or=10 4 eV. Differentiation of the extrapolated range-energy expression yields an effective stopping power along the projected track of the electron and is given by: dE/dR ex =E/(R ex (0.15546 ln(E)+0.31104)) eV cm 2 mu g -1 , 20 eV