Decay of a Resonance in 18^Ne by the Simultaneous Emission of Two Protons

Radioactive ion beams of {sup 17}F were used to study several resonance states in {sup 18}Ne . Clear evidence for simultaneous two-proton emission from the 6.15MeV state (J{sup {pi}}=1{sup -}) in {sup 18}Ne has been observed with the reaction {sup 17}F+{sup 1}H . Because of limited angular coverage, the data did not differentiate between the two possible mechanisms of simultaneous decay, diproton ({sup 2}He ) emission or direct three-body decay. The two-proton partial width was found to be 21{+-}3 eV assuming {sup 2}He emission and 57{+-}6 eV assuming three-body decay. The total width of the 1{sup -} state was measured to be 50{+-}5 keV . Several additional resonances that decay by single proton emission were also studied.