BNL, Upton, Long Island, New York, USA
The next generation of high-energy nuclear physics experiments involve colliding high-energy electrons with ions, as well as colliding polarized electrons with polarized protons and polarized helions (Helium-3 nuclei). The eRHIC project proposes to add an electron accelerator to the RHIC complex, thus allowing all of these types of experiments to be done by combining existing capabilities with high energy and high intensity electrons. In this paper we describe the controls systems requirements for eRHIC, the technical challenges, and our vision of a control system ten years into the future. What we build over the next ten years will be what is used for the ten years following the start of operations. This presents opportunities to take advantage of changes in technologies but also many challenges in building reliable and stable controls and integrating those controls with existing RHIC systems. This also presents an opportunity to leverage on state of the art innovations and build collaborations both with industry and other institutions, allowing us to build the best and most cost effective set of systems that will allow eRHIC to achieve its goals.
BNL, Upton, Long Island, New York, USA
Upgrading hundreds of machines to the next major release of an Operating system (OS), while keeping the accelerator complex running, presents a considerable challenge. Even before addressing the challenges that an upgrade represents, there are critical questions that must be answered. Why should an upgrade be considered? (An upgrade is labor intensive and includes potential risks due to defective software.) When is it appropriate to make incremental upgrades to the OS? (Incremental upgrades can also be labor intensive and include similar risks.) When is the best time to perform an upgrade? (An upgrade can be disruptive.) Should all machines be upgraded to the same version at the same time? (At times this may not be possible, and there may not be a need to upgrade certain machines.) Should the compiler be upgraded at the same time? (A compiler upgrade can also introduce risks at the software application level.) This paper examines our answers to these questions, describes how upgrades to the Red Hat Linux OS are implemented by the Controls group at RHIC, and describes our experiences.