[en] The study of nuclei far from beta stability is hampered greatly when the nuclide of interest decays in a manner identical to that of a nuclide produced in greater yield in the same bombardment. One solution to this problem is through the use of an on-line mass separator. Development of the Berkeley helium-jet fed on-line mass separator RAMA is discussed as applied to studies of the A = 4n, T/sub z/ = -2 nuclides. RAMA has typical efficiencies of 0.1% for approx. 75 elements with melting points less than or equal to 2000⁰C. This efficiency permits decay studies to be readily performed on nuclei with production cross sections greater than or equal to 500 μb for γ-ray spectroscopy and greater than or equal to 1 μb for discrete-energy charged-particle spectroscopy. The mass range on the normalized RAMA focal plane is +-10%. The quoted efficiency is for a mass resolution of M/ΔM approx. 300. RAMA has been used to observe two members of the A =4n, T/sub z/ = -2 series of beta-delayed proton emitters, ²⁰Mg and ²⁴Si. Observation of beta-delayed protons from a mass-separated sample of ²⁰Mg(t/sub 1/2/ approx. 95 ms) establishes the mass excess of the lowest T = 2(0⁺) state in ²⁰Na (13.42 +- .05 MeV), and thereby completes the mass-twenty isospin quintet. A similar measurement of the decay of ²⁴Si(t/sub 1/2/ approx. 100 ms) establishes the mass excess of the lowest T = 2(0⁺) state in ²⁴Al(5.903 +- 0.009 MeV). The mass-24 isospin quintet is incomplete because the mass of ²⁴Si remains unknown. In both cases, excellent agreement is obtained with only the quadratic form of the isobaric multiplet mass equation

[en] Results from the RAMA-88 system at the Lawrence Berkeley Laboratory are being used to design a new helium-jet and ion source system for the UNISOR project. This system should complement the existing integrated target-ion source to extend UNISOR's capabilities to include a majority of the chemical elements. This fast transport helium-jet system should permit studies of nuclides with half-lives down to 50 ms

[en] The study of nuclei far from beta stability is hampered greatly when the nuclide of interest decays in a manner identical to that of a nuclide produced in greater yield in the same bombardment. Attempts to observe the protons associated with the decay of the A = 4n, T/sub z/ = -2 series of beta-delayed proton emitters failed because of the large number of protons arising from the strong beta-delayed proton decay of the A = 4n + 1, T/sub z/ = -3/2 nuclides. One solution to this problem is through the use of an on-line mass separator. Development of the Berkelely helium-jet fed on-line mass separator RAMA is discussed as applied to studies of the A = 4n, T/sub z/ = -2 nuclides. RAMA (Recoil Atom Mass Analyzer) has typical efficiencies of 0.1% for approx. 75 elements with melting points less than or equal to 2000⁰C. This efficiency permits decay studies to be readily performed on nuclei with production cross sections greater than or equal to 500 μb for γ-ray spectroscopy and greater than or equal to 1 μb for discrete energy charged particle spectroscopy. The mass range on the normalized RAMA focal plane is +- 10%. The quoted efficiency is for a mass resolution of M/ΔM approx. 300. RAMA has been used to observe two members of the A = 4n, T/sub z/ = -2 series of beta-delayed proton emitters, ²⁰Mg and ²⁴Si. Observation of beta-delayed protons from a mass-separated sample of ²⁰Mg(t/sub 1/2/ approx. 95 ms) establishes the mass-excess of the lowest T = 2 (0⁺) state in ²⁰Na (13.42 +- .05 MeV), thereby completing the mass twenty isospin quintet. A similar measurement of the decay of ²⁴Si (t/sub 1/2/ approx. 100 ms) establishes the mass-excess of the lowest T = 2 (0⁺) state in ²⁴Al (5.903 +- 0.009 MeV). The mass 24 isospin quintet is incomplete because the mass of ²⁴Si remains unknown

[en] Preliminary ideas are presented for the scientific justification of a storage ring for radioactive beams. This storage ring would be suitable for many nuclear and atomic physics experiments. Ideally, it would be constructed and tested at an existing low-energy heavy-ion facility before relocation to a major radioactive beam facility

[en] Results from the RAMA-88 system at the Lawrence Berkeley Laboratory are being used to design a new helium-jet and ion source system for the UNISOR project. This system should complement the existing integrated target-ion source to extend UNISOR's capabilities to include a majority of the chemical elements. This fast transport helium-jet system should permit studies of nuclides with half-lives down to 50 ms. (orig.)

[en] Recent work in light proton-rich nuclei is reviewed. Evidence for the first T/sub z/ = -5/2 nuclide, ³⁵Ca, is presented. The mechanisms of two-proton emission following beta-decay is investigated. Future directions in this field are discussed. 23 refs., 5 figs

[en] Although there exists a small number of very important nuclear astrophysics experiments which require radioactive nuclear beams (RNB), most proposed experimental attention has been focused on nuclear spectroscopy and the narrow subset of experiments on neutron halos. Unfortunately, most of these experiments require rather large beam intensities (>10⁹ pps). Initial beam intensities from any proposed RNB facility will likely be less than 10⁹ pps as will the interesting beams on the limits of nuclear stability. Thus more attention needs to be paid to experiments designed for these lower intensity beams. The author covers several examples of interesting physics which can be accomplished with these lower beam intensities such as resonant nuclear reactions, mass measurements and quark structure of nucleons

[en] The ⁴⁰Ca(²⁴Mg, ³N) reaction has been used to observe β-delayed protons from ⁶¹Ge. A preliminary decay scheme is reported and includes predicted energies, spine, parities, isospin values and estimated branching ratios

[en] The author discusses the application of a storage ring as a component of the ISL facility. The ring would have the advantage of relatively large luminosities for small beam intensities. It would also spread the background due to radioactive decay products over a very large area, decreasing this background problem. A storage ring is not the best mass measuring instrument however, and to operate it as such is to run it in an unstable mode. In addition to solving this particular problem, the mass measuring method, relying upon time of flight, requires fairly long cooling and purification times, and limits the application of the storage ring to isotopes with half lives greater than 1 second

[en] There has been significant discussion in consideration of a high resolution mass separator followed by a RFQ and a linear accelerator as the basic format for IsoSpin Laboratory. There exists another strong possibility-namely a low-resolution mass separator coupled to a cyclotron. The major objection to this approach has been that the conservation from the +1 mass separator beam to a q/m beam of 1/4 to 1/3 is thought to be highly inefficient. Since we are in the fortunate position of having the two expensive components of this system available for tests (an on-line mass separator and an ECR source), we intend to couple these devices to actually measure these efficiencies and to test ideas for improving the efficiency. We present some specifics of this approach