A RECOIL SEPARATOR FOR THE MEASUREMENT OF RADIATIVE-CAPTURE REACTIONS

A recoil separator in combination with a windowless target has been de signed for the measurement of the radiative capture reaction p(Be-7, g amma)B-8. The separator consists of momentum and velocity filters and a Delta E-E detector telescope. The setup was tested quantitatively us ing p(C-12,gamma)N-13 reaction at the effective energy E(cm) = 841 keV . Projectile fluxes were measured directly with Faraday cups and indir ectly with elastic backscattering into Si detectors, while the N-13 re coil flux was measured directly with Delta E-E telescope. A suppressio n of the C-12 beam particles by a factor 2 X 10(-10) was observed when the system was tuned for the recoil N-13's. Special emphasis was give n to the charge state probabilities of the N-13 recoils. Possible impr ovements of the system for the measurement of other capture reactions are discussed.