Abstract
A rotating target for the second target station (STS) at SNS has been identified as an option along with a mercury target. Evaluation of the rotating target alternative for STS has started at 1.5 MW which is considered an upper bound for the power. Previous preconceptual design work for a 3 MW rotating target is being modified for the lower power level. Transient thermal analysis for a total loss of active water cooling has been done for a simplified 2D model of the target and shielding monolith which shows that peak temperatures are well below the level at which tungsten vaporization by steam could exceed site boundary dose limits. Design analysis and integration configuration studies have been done for the target-moderator-reflector assembly which maximizes the number of neutron beam lines and provides for replacement of the target and moderators. Target building hot cell arrangement for this option will be described. An option for operation in rough vacuum without a proton beam window using Ferro fluid seals on a vertical shaft is being developed. A full scale prototypic drive module based on the 3 MW preconceptual design has been fabricated and successfully tested with a shaft and mock up target supplied by the ESS-Bilbao team. Overall planning leading to decision between mercury and the rotating target in 2011 will be discussed
