Proton beams from a nanotube accelerator Available to Purchase

Carbon nanotubes (CNTs) are hardy and versatile, with remarkable material and electronic properties. And they could be useful in some extreme conditions as well. Two physicists in Japan, Masakatsu Murakami of Osaka University and Motohiko Tanaka of Chubu University, propose using a CNT as a shotgun barrel to shoot a beam of protons. Their scheme nests two small hydrogen-rich fragments—which could be water ice, paraffin, or some other low-Z material but were modeled as hydrogen nanotubes—within a larger CNT that has gold atoms chemically adsorbed in its wall. The assembled structure is then zapped from the side with an ultraintense femtosecond laser pulse (green in the schematic). As shown in three-dimensional simulations, the laser partially ionizes the gold and fully ionizes the hydrogen and carbon in the assemblage; after a few swings of the laser’s electric field, significant numbers of electrons (white) are blown off and form a...