G. K. Pang

Design of superferric magnet for the cyclotron gas stopper project at the NSCL

We present the design of a superferric cyclotron gas stopper magnet that has been proposed for use at the NSCL/ MSU to stop the radioactive ions produced by fragmentation at high energies (~140 MeV/u). The magnet is a split solenoid-dipole with three sectors (Bave~ 2.7 T at the center and 1.7 T at the pole-edge.) The magnet outer diameter is 3.8 m, with a pole radius of 1.1 m and B*rho= 1.7 T-m. The field shape is obtained by extensive profiles in the iron. The coil cross-section is 80 mm times 80 mm and peak field induction on the conductor is about 2.05 T. The upper and lower coils are in separate cryostats and have warm electrical connections. We present the coil winding and the protection schemes. The forces are large and the implications on the support structure are presented.

The LEBIT facility at MSU. High-precision mass measurements at a fragmentation facility

The low-energy beam and ion trap facility LEBIT at the NSCL at MSU has demonstrated that rare isotopes produced by fast-beam fragmentation can be slowed down and prepared such that precision experiments with low-energy beams are possible. For this purpose high-pressure gas-stopping is employed combined with advanced ion manipulation techniques. Penning trap mass measurements on short-lived rare isotopes have been performed with a 9.4 T Penning trap mass spectrometer. Examples include 66As, which has a half-live of only 96 ms, and the super-allowed Fermi-emitter 38Ca, for which a mass accuracy of 8 ppb (280 eV) has been achieved. The high accuracy of this new mass value makes 38Ca a new candidate for the test of the conserved vector current hypothesis.

High precision Penning trap mass spectrometry of rare isotopes produced by projectile fragmentation

The Low Energy Beam and Ion Trap (LEBIT) is the only present facility to combine high precision Penning trap mass spectrometry with fast beam projectile fragmentation. Located at the National Superconducting Cyclotron Laboratory (NSCL), LEBIT is able to measure radionuclides produced in a chemically independent process with minimal decay losses. Recent exotic mass measurements include 66As, 63-66Fe, and 32Si. 66As is a new candidate to test the Conserved Vector Current (CVC) hypothesis. The masses of the neutron-rich iron isotopes provide additional information about the mass surface and the subshell closure at N = 40. 32Si is a member of the A = 32, T = 2 quintet; its measurement permits the most stringent test of the validity of the isobaric multiplet mass equation (IMME). An overview of some recent measurements will be presented as well as advanced techniques for ion manipulation.

Improved Mass Measurements of Nuclei Around N=Z=34

Joshua Savory ∗,a,b, C. Bachelet a, M. Block a, G. Bollen a,b, M. Facina a, C.M. Folden IIIa, C. Guénaut a, E. Kwan a,b, A.A. Kwiatkowski a, D.J. Morrissey a,c, G.K. Pang a,c, A. Prinke a,b, R. Ringle a,b, H. Schatz a,b, P. Schury a,b, S. Schwarz a, C.S. Sumithrarachchi a,c a National Superconducting Cyclotron Laboratory, East Lansing, MI 48824, USA b Department of Physics and Astronomy, East Lansing, MI 48824, USA c Department of Chemistry, East Lansing, MI 48824, USA

rp Process and Masses of N{approx_equal}Z{approx_equal}34 Nuclides

High-precision Penning-trap mass measurements of the

Precision mass measurements of rare isotopes near N = Z = 33 produced by fast beam fragmentation

N\ensuremath{\approx}Z\ensuremath{\approx}34

Discovery of a Nuclear Isomer in 65Fe with Penning Trap Mass Spectrometry

nuclides

Rp Process and Masses of N ≈ Z ≈ 34 Nuclides

^{68}\mathrm{Se}

rpProcess and Masses ofN≈Z≈34Nuclides

,

Precision test of the isobaric multiplet mass equation for the A = 32, T = 2 quintet

^{70}\mathrm{Se}