@Milemaster:
While I’m not particularly knowledgeable on the difficulties presented to a combined capacitor/photovoltaic system I strongly suspect it will not be practical from an engineering point. We already know the X-Ray photovoltaics look to be the main engineering challenge after viable fusion is demonstrated. The X-Ray collectors efficiency is crucial to the final system net output and estimates are that 20% will be needed just for break-even. Thus all effort should be directed solely towards maximum efficiency and the more functionality that can be offloaded to other equipment the better particularly when that function is easily found in off the shelf components such as a capacitor bank or a vacuum chamber. Even with the ‘Roll’ being designed purely for photovoltaic collection I predict it will easily exceed 50% of the total system capitol costs, it is by far the part that will be most complex to fabricate because it will be a completely NEW device manufactured only for the FF Generator, that means new specialized equipment in small quantities. All that means Big costs.