Our key innovation will be the use of single-layer graphene as LENA conversion foils, with appropriate microgrids and nanogrids to support the foils. Phase I develops a way to make the freestanding foils with usable size and perfection, and investigates added features such as EUV blocking. Phase II will make modifications to the graphene foil itself as needed for specific types of missions. For example, the existing graphene may be suitable in cases where incident LENA flux is high and the energy range of the instrument is high. Modified graphene may be necessary to increase conversion efficiency for converting to particular species, such as H+ or O-. In our proposal, we have fabricated small graphene coupons using existing methods, and shown these to optically consist of a carbon monolayer. The single-layer graphene mass density is 10X lower than conventional amorphous carbon foils. The Phase I activities build on this demonstration, and advances the TRL from the present TRL3 to TRL4. Phase I also comprises modeling and analysis in preparation for Phase II, which is expected to begin at TRL4 and end at TRL6.