If the sails can't absorb or reflect the radiation there won't be any transfer of energy. In other words, if the X-rays pass straight through the (X-ray-transp

If the sails can't absorb or reflect the radiation there won't be any transfer of energy. In other words, if the X-rays pass straight through the (X-ray-transparent) sail they won't impart any energy to it. As an analogy, a yacht's sails made of chicken wire won't catch much wind.