| Paper | Title | Page |
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| TPPE033 | A Comparison of Electrostatic and Magnetic Focusing of Mixed Species Heavy Ion Beams at NSCL/MSU | 2281 |
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Funding: This work has been supported by National Science Foundation under grant PHY-0110253. Experience at the National Superconducting Cyclotron Laboratory has shown the first focusing element after the electron cyclotron resonance ion source (ECRIS), before the beam is analyzed by a magnetic dipole, to be critical to subsequent beam transport and matching. Until 2004, both ion sources at the NSCL used a solenoid as this first focusing element. Observation of hollow beam formation led to further analysis and the decision to replace the solenoid with an electrostatic quadrupole triplet on a test basis [1]. Substantial increases in net cyclotron output were achieved, leading us to adopt electrostatic quadrupole focusing as the permanent configuration. In addition, a sextupole magnet was installed in this beam line. Motivations for these changes and results of operating experience are discussed. |
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| TPPE034 | Possible Scheme of the Analyzing Part of a Cyclotron Injection Beamline with Higher Energy | 2345 |
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Funding: This work was supported in part by the National Science Foundation under grant PHY-0110253. The ion beam produced with an ECR ion source (ECRIS) with an extraction voltage of 30 kV may be additionally accelerated using a negative voltage of -30 kV applied to the last electrode of the extraction system, connected to the beamline biased to the same -30 kV potential. In this way the kinetic energy of the beam is increased to 60 keV/q, decreasing to half the space charge effect on the beam emittance. Using a large gap analyzing magnet placed right after the ECRIS and no focusing element, the transmission is still close to 100%. The voltage on the beamline must be kept constant from the ECRIS till the image focal plane of the analyzing magnet where the full separation of the beam charge states is achieved. An insulator break separates the biased beamline from the downstream section, which is at zero potential. Passing through this section of the beamline, the ion beam is decelerated to 30 keV/q, the energy necessary for the injection in the cyclotron. In order to prevent the increase of the beam divergence, a focusing solenoid is installed behind the break point. This work will present the results of a simulation of the transport of an argon beam in the proposed beamline. |