[en] The current scheme for ion-beam injection into the coupled cyclotron accelerator at the NSCL involves the use of two electron cyclotron resonance (ECR) ion sources. The first one is a 6.4 GHz fully superconducting that will be replaced within two years by SUSI, a third generation 18 GHz superconducting ECR ion source. The other source, ARTEMIS, is a room-temperature source based on the AECR-U design and built in collaboration with the University of Jyvaeskylae in 1999. Due to cyclotron operation constraint, very little time can be allowed to ion source development and optics studies of the cyclotron injection beam line. In this context, NSCL has decided to build ARTEMIS-B an exact replica of its room-temperature ECR ion source. The goal of this project is threefold. One is to improve the overall reliability of cyclotron operation through tests and studies of various ion source parameters that could benefit beam stability, tuning reproducibility, and of course overall extracted currents performance. Second is to implement and test modifications or upgrade made to the ion source: extraction geometry, new resistive or rf oven design, dual frequency use, liner, etc. Finally, this test source will be used to study various ion optics schemes such as electrostatic quadrupole doublet or triplet at the source extraction or the use of a correction sextupole and assess their effect on the ion beam through the use of an emittance scanner and imaging viewer that will be incorporated into ARTEMIS-B beam line. This article reviews the design and construction of ARTEMIS-B along with some initial commissioning results

[en] The goal of the low-energy-beam and ion-trap (LEBIT) project is to convert the high-energy exotic beams produced at NSCL/MSU into low-energy low-emittance beams. This beam manipulation will be done by a combination of a high-pressure gas stopping cell and a radio-frequency quadrupole ion accumulator and buncher. The first experimental program to profit from the low-energy beams produced will be high-accuracy mass measurements on very short-lived isotopes with a 9.4 T Penning trap system. The status of the project is presented with an emphasis on recent stopping tests range of 100 MeV/A ⁴⁰Ar¹⁸⁺ ions in a gas cell

[en] As a first step towards developing liquid lithium target technology for a future high-power nuclear physics fragmentation facility, an adjustable thickness Li/Be hybrid target is being constructed for use at the NSCL. This target will use beryllium windows with flowing lithium. The lithium serves as a part of the target as well as the coolant. Up to 1 kW of beam power is dissipated in the target and is carried away by the recirculating liquid lithium loop. It is designed for high power beams in the mass range from oxygen to calcium. Tapered beryllium windows combined with a uniform thickness lithium channel gives an overall target thickness ranging from 0.7 g/cm² to 3 g/cm², which is adjusted by moving the target vertically. The target system design is complete and is described in this paper

[en] An ECR ion source is being designed to initially serve as a test bench for development and later will replace the existing 6.4 GHz SC-ECRIS. This ECRIS will operate at 18+14.5 GHz microwave frequencies. The radial magnetic field will be produced by a superconducting hexapole coil, capable of 1.5 T at the aluminum plasma chamber wall (R=50 mm). The axial trapping will be produced with six superconducting solenoids enclosed in an iron yoke. We will present the Flexible Axial Magnetic Field Concept, introduced for the first time in this design, which will allow tuning the distance between the plasma electrode and resonant zone in the plasma. The distance between the two axial magnetic maxima will be also tunable in the range of 340 to 460 mm

[en] A new electron cyclotron resonance ion source (ECRIS) was constructed at the NSCL/MSU to replace the existing SC-ECRIS. This ECRIS operates at 18+14.5 GHz microwave frequencies with a planned upgrade to 24-28 GHz in the second phase of commissioning. A superconducting hexapole coil system produce the radial magnetic field; the axial trapping is produced with six superconducting solenoid coils enclosed in an iron yoke to allow the optimization of the distance between the plasma electrode and the resonant zone in the plasma. We report the details of the design, construction, and initial commissioning results of this new ECRIS

[en] The Low Energy Beam and Ion Trap (LEBIT) Project aims to convert the high-energy exotic beams produced at NSCL/MSU into low-energy low-emittance beams. A combination of a high-pressure gas stopping cell and a radiofrequency quadrupole (RFQ) ion accumulator and buncher will be used to manipulate the beam accordingly. High-accuracy mass measurements on very short-lived isotopes with a 9.4 T Penning trap system will be the first experimental program to profit from the low-energy beams. The status of the project is presented with a focus on recent stopping tests of 100-140 MeV/A Ar18+ ions in a gas cell

No abstract available

[en] Gas stopping is becoming the method of choice for converting beams of rare isotopes obtained via projectile fragmentation and in-flight separation into low-energy beams. These beams allow ISOL-type experiments, such as mass measurements with traps or laser spectroscopy, to be performed with projectile fragmentation products. Current gas stopper systems for high-energy beams are based on linear gas cells filled with 0.1-1 bar of helium. While already used successfully for experiments, it was found that space charge effects induced by the ionization of the helium atoms during the stopping process pose a limit on the maximum beam rate that can be used. Furthermore, the extraction time of stopped ions from these devices can exceed 100 ms causing substantial decay losses for very short-lived isotopes. To avoid these limitations, a new type of gas stopper is being developed at the NSCL/MSU. The new system is based on a cyclotron-type magnet with a stopping chamber filled with Helium buffer gas at low pressure. RF-guiding techniques are used to extract the ions. The space charge effects are considerably reduced by the large volume and due to a separation between the stopping region and the region of highest ionization. Cyclotron gas stopper systems of different sizes and with different magnetic field strengths and field shapes are presently investigated.

[en] A status report of the design and fabrication of a new, fully superconducting electron cyclotron resonance ion source will be presented. The Superconducting Source for Ions (SuSI) first will operate at 18+14.5 GHz microwave frequencies. A short description of the magnet structure and the injection and extraction hardware will be presented. Several innovative solutions are described, which will allow maximum flexibility in tuning SuSI in order to match the acceptance of the coupled cyclotrons. Details of an ultrahigh temperature inductive oven construction are given as well as a description of the low-energy beam transport line

[en] The magnet for the cyclotron gas stopper is a newly designed, large warm-iron superconducting cyclotron sector gradient dipole. The maximum field in the centre (gap = 0.18 m) is 2.7 T. The outer diameter of magnet yoke is 4.0 m, with a pole radius of 1.1 m and B^*ρ = 1.8 T m. The fabrication and assembly of the iron return yoke and twelve pole pieces is complete. Separate coils are mounted on the return yokes that have a total mass of about 167 metric tons of iron. This paper illustrates the design and the fabrication process for the cyclotron gas-stopper magnet that is being fabricated at MSU.