Graphene is an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in an hexagonal lattice. It is the basic structural element of many other allotropes of carbon, such as graphite, charcoal, carbon nanotubes and fullerenes.
In cases where surgery and radiation are combined, proton therapy is an ideal part of brain cancer treatment. Different brain tumors require different doses of radiation for control and eradication. Like any other organ in the body, the brain can only tolerate a limited amount of radiation.
Q: A beam of nuclei is used for cancer therapy. Each nucleus has an energy of 183 MeV, and the relative biological effectiveness (RBE) of this type of radiation is 16. The beam is directed onto a 0.220-kg tumor, which receives a biologically equivalent dose of 153 rem.