Low-conductivity water systems for accelerators

The performance of low-conductivity water (LCW) systems is of critical importance at accelerator facilities. An imbalance of water chemistry, supply temperature, or component availability can have a direct impact on machine performance. Downtime of the LCW system for any reason can result in downtime of the entire accelerator. LCW systems for copper components are similar to stator cooling systems for electric power generating equipment with respect to the chemistry of soluble copper and resultant corrosion. The basics of copper corrosion and agglomeration mechanisms, impact of dissolved oxygen concentration and pH, copper solubility data and its relationship with temperature, and relative corrosion rates for various possible operating regimes are available from existing literature and will be reviewed. Water treatment for aluminum LCW systems is different than for copper systems and will be outlined. Fundamental features of control systems capable of controlling LCW temperatures within a fraction of a degree will also be discussed. Operational reliability is very much related to system design, component selection, and operating practices, and some anecdotal information will be offered based on the author´s experience.