The Rare Isotope Accelerator (RIA) Linac driver requires a great variety of high charge state ion beams with up to a magnitude higher intensity than currently achievable for the heaviest masses. The goal of the RIA injector R&D program for VENUS is the reliable production of intense medium charge state ion beams, e.g. 8 puA (particle µA) of U 29+ . Therefore, the superconducting ECR ion source VENUS has been designed from the beginning for optimum operation at 28 GHz at high power (10 kW). In addition, a high intensity Low Energy Beam Transport, LEBT, that was developed to analyze and transport these multiply-charged, space charge dominated beams. During the last year VENUS was commissioned at 18 GHz and preparations for 28 GHz operation continued. Tests with various gases and recently metals have been performed with up to 2000 W of 18 GHz RF power. Promising performance has been measured in those preliminary beam tests. For example, 180 pµA of O 6+ , 15 pµA of Ar 12+ , 7.5 puA of Xe 20+ and 4puA of Bi 24+ were produced in the early commissioning phase, ranking VENUS among the currently highest performance 18 GHz ECR ion sources. In FY04 a 10 kW 28 gyrotron system will be added, which will enable VENUS to reach full performance. The emittance of the beams produced at 18 GHz was measured with a two axis emittance scanner developed with earlier RIA R&D funds.

The construction of VENUS, a next generation superconducting Electron Cyclotron Resonance ion source designed to operate at 28 GHz, is complete. The cryostat including the superconducting magnet assembly was delivered in September 2001. During acceptance tests, the superconducting magnets produced an axial magnetic field strength of 4T at injection, 3T at extraction, and a radial field strength of 2T at the plasma chamber wall without any quenches. These fields are sufficient for optimum operation at 28 GHz. The cryogenic system for VENUS has been designed to operate at 4.2 K with two cryocoolers each providing up to 45 W of cooling at 50 K and 1.5 W at 4 K in a closed loop mode without further helium transfers. However, during the acceptance tests an excessive heat leak of about 3W was measured. In addition, the liquid helium heat exchanger did not work properly and had to be redesigned. The cryogenic system modifications will be described. In addition, an update on the installation of the ion source and its beam line components will be given.

A new, very high magnetic field superconducting ECR ion source, VENUS, is under development at the LBNL 88-Inch Cyclotron. It will boost the maximum energies and intensities for heavy ions from the cyclotron particularly for ions with mass greater than 60. It will also serve as R&D ion source for the proposed Rare Isotope Accelerator (RIA) project in the US, which requires up to 10 pµA of U 30+ . The superconducting magnet structure consists of three solenoids and six racetrack coils with iron poles forming the sextupole. The coils are designed to generate a 4T axial mirror field at injection and 3T at extraction and a radial sextupole field of 2.4 T at the plasma chamber wall. Test results of the magnet coils, which exceeded design requirements with minimum training, are presented. The magnet assembly with its cryostat will be enclosed by an iron shield and therefore must be designed to withstand any possible forces between coils and iron, which can be as high as 35,000 kg-force. The low energy beam transport line (LEBT) and mass analyzing system of the ion source is designed to transport a proton-equivalent current of 25mA at 20kV extraction voltage. The design of the ion source and LEBT will be discussed.

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