Production of exotic (or polarized) low-energy radioactive beams via two successive nuclear reactions: tertiary beams

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 422; no. 1; pp. 505 - 509
• Main Authors: Becchetti, F.D., Lee, M.Y., O'Donnell, T.W., Roberts, D.A., Zimmerman, J.A., Kolata, J.J., Guimarães, V., Peterson, D., Santi, P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1999
• Subjects: Polarized beams; Radioactive nuclear beams; Polarized beams; Radioactive nuclear beams
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/S0168-9002(98)01075-4

We propose a method to produce usable amounts (1–100/s) of low-energy, very neutron-, proton-rich or highly-polarized radioactive nuclear beams (RNBs) via a two-stop production method which utilizes a high-intensity secondary RNB with a second production target. For example: 7Li+ 9Be→ 8Li+ 9Be→ 9Li. The latter ( 9Li) is very difficult to produce at low energies (a few MeV/u) as it is several nucleons away from the line of stability and no efficient one-step mechanism exists. In contrast, high-cross-section transfer reactions such as 9Be( 7Li, 8Li) combined with a high-efficiency ion-optical collection devices can produce 8Li and other near-stability RNBs ( 8B, 7Be, 6He,…) at very good intensities, viz. 10 4–10 8/s. Thus, it appears feasible to use a second, high cross-section reaction – perhaps now with a radioactive or polarized second production target, to produce and exotic, low-energy tertiary RNBs, including polarized RNBs. These and other aspects are described together with some initial tests using the new UM-UND TwinSol RNB apparatus (see M. Lee, this Proceedings).