The lost nuclear fusion reactor design? Guest Blogger / 3 hours ago March 31, 2015 Robert Bussard, one of the giants of the field, claimed to his dying day he had cracked the problemAbove: a homemade version of the Polywell nuclear fusion reactorGuest essay by Eric WorrallNot many people have heard of Robert Bussard, but he was one of the giants of nuclear fusion research.