Linear energy transfer for electrons

[Biocool]

Hi! I have a question about Linear Energy Transfer for electrons. According to the definition the linear energy transfer is equal to the energy dE which a charged particle loses at a distance dl. But what does dl mean in case of electrons? Is LET calculated per unit of full path length or per unit of linear path length? Thanks.

 

[gleem]

LET is the ratio of the energy deposited (dE) in a medium by an ionizing particle of a given energy to the incremental distance (dl) it traversed..
LET changes with energy.

Let me add that the LET of a given real radiation beam is the average LET along its full path. For an electron which is strongly interacts with the medium loses energy quickly and produces secondary electrons of greatly varying energy and LET. Thus it only make sense to talk about the average energy loss per unit length.