Distortions in the Einstein ring of strong lens systems offer a powerful new avenue for discriminating between the standard Lambda CDM paradigm and large classes of alternative DM models (e.g. Warm Dark Matter). In order to make accurate predictions for the abundance of substructure as the relevant mass scales, new simulation techniques are required in order to ease the computational burden. Specifically, we implement specialised initial conditions. In this talk I'll discuss why we need these new initial conditions, how they are implemented and our preliminary results.
