Signal in Silicon from 10MeV electron

radiation length in mass per area as a function of material charge number and mass number

numbers for silicon

silicon radiation length in mm

fraction of a radiation length for 1mm silicon

From Figure 26.9 of "particle data passage of particles through matter" at 10 MeV the ionization energy loss is:

call it

This gives us the ionization energy loss in 1 mm of silicon as:

The energy required to create an electron hole pair in silicon is:

Energy in Si to produce one pair

F. Scholze et al.

Minimum signal created by passage of a 10 MeV electron through 1 mm of silicon

If the 10 MeV electrons make it through the aluminum they will have lost energy and will, as shown in Fig. 26.9, leave more energy than our calculated number.

(does this number make sense?) We know that minimum ionizing particles create 80 electron hole pairs in a micron of silicon or:

in 1 mm

So our number looks low even if we include the other energy loss mechanisms. Fig. 26.9 is for Pb - apparently things don't simply scale as radiation length.