of ten in pulse energy. Given such a choice, the analysis presented here suggests that the gain in signal from a longer pulse with higher pulse energy compensates for the increase in damage. We note though, this conclusion only applies to spatially uncorrelated damage processes like ionization and ion diffusion (not a Coulomb explosion). Figure \[fig:pulselength\_SNR\] shows that $SNR_{D+N}(q)$ and $SNR_D(q)$ have a weak dependence on pulse duration at constant pulse energy. This suggests that maximizing pulse energy has a greater influence on the success of single molecule imaging than pulse duration with respect to the spatially uncorrelated damage mechanisms considered here.

If multiple molecules were simultaneously aligned and exposed to the x-ray pulse (as described in the Introduction), we would still expect a gating effect qualitatively similar to that shown in Fig. \[fig:selfgating\_AB\]. However, we would expect $SNR_{D+N}(q)$ and $SNR_D(q)$ to scale as $\sqrt{N_{\rm mol}}$, where $N_{\rm mol}$ is the average number of molecules in the beam for each exposure. This is because the signal is proportional to $N_{\rm mol}$, while standard deviations of the damage noise and shot noise scale as $\sqrt{N_{\rm mol}}$. This analysis is missing the additional fluctuations due to the coherent interference between molecules, which 