ECRIS08 - List of Authors (Prestemon, S.)

A B C D E F G H I J K L M N O P R S T U V W Y Z

Prestemon, S.

Paper	Title	Page
MOCO-A02	Status Report and Recent Developments with VENUS	2
	D. Leitner, J. Y. Benitez, D. R. Dietderich, R. Hannaford, M. Leitner, C. M. Lyneis, S. Prestemon, D. S. Todd LBNL, Berkeley, California
	Since the superconducting ECR ion source VENUS started operation with 28 GHz microwave heating in 2004, it has produced record ion beam intensities such as 860 euA of Ar¹²⁺, 200 euA of U³⁴⁺, or in respect to high charge state ions, 270 euA of Ar¹⁶⁺, 1 euA of Ar¹⁸⁺ and .4 euA of Xe⁴²⁺. In August of 2006 VENUS has been connected to the 88-Inch Cyclotron as the third injector ion source extending the energy range and available heavy ion beam intensities from the cyclotron. This paper will highlight recent developments and results. In addition, the paper will give an update on the ongoing VENUS repair. Following an unexpected quench in January of 2008, the sextupole coils could not be energized. Most likely the quench was caused by the loss of liquid helium in the upper cryostat, which resulted in localized heating of the lead wire and consequent quenching. After opening the cryostat, it was found that one of the current carrying leads of the sextupole magnet was burned. The wire damage made it necessary to open the cold mass and extract the coil assembly for the repair. An update on the major undertaking of repairing the VENUS magnet and rebuilding the cryostat will be presented.
	Slides
TUCO-A01	Conceptual Design of a 56 GHz ECR Ion Source Magnet Structure	127
	C. M. Lyneis, S. Caspi, P. Ferracin, D. Leitner, S. Prestemon, G. L. Sabbi, D. S. Todd, F. Trillaud LBNL, Berkeley, California
	Funding: This work was supported by the Director, Office of Science, OFfice of High Energy and Nuclear Physics, Division of Nuclear Physics, US Department of Energy under Contract No. DE-AC02-05CH11231. The development of a 4th Generation ECR ion source, which could operate at 56 GHz twice that of 3rd Generation sources, presents several technical challenges.* The greatest challenge is to produce a magnet structure with sufficient field strength to adequately confine the plasma. A design study is underway to determine the feasibility and engineering issues associated with a magnet structure that could produce 8 T at injection, 6 T at extraction and 4 T radially. The initial analysis shows that peak fields in the superconductor would be roughly 12 to 14 T and this is above Bc2 for NbTi but less than Bc2 for Nb3Sn. We are evaluating two possible designs; the classic design, where the sextupole coils are places inside the solenoids and the inverted design where the sextupole is placed outside the solenoid magnets. The preliminary results of the ongoing study are being presented and discussed. * Claude M Lyneis, D. Leitner, D. S. Todd, G. Sabbi, S. Prestemon, S Caspi and P. Ferracin, Rev. Sci. Instrum. 79, 02A321 (2008)
	Slides