Fig. 2.

Measurement of spot fading on Paraffin crystals at liquid-nitrogen(LN${}_{\mathbf{2}}$, dashed green line) and liquid-helium temperature (LHe, solid blue line). The normalised intensity of the diffraction spots within the 4 Å resolution band is plotted on a logarithmic scale versus to cumulative electron fluence. The fluence at which the averaged intensity reaches $1/e$ of its initial value is labelled as $N_e$ for the two temperatures. The ratio $N_e$(LHe)/$N_e$(LN${}_2$) was found to be 1.54.