SPS and LEP controls, status and evolution towards the LHC era

LEP was the first CERN accelerator to be built with a Control System based largely on off-the-shelf technology. Operational experience has confirmed the strategies of the original design. However, to maintain this system, components have to be renewed and in order to meet the increasing user demands the system requires continuous investment. These factors have ensured that the Control System is still based on a modern computer infrastructure and the recent extension to the SPS machine and its Experimental Areas has been achieved without any specific developments of the basic infrastructure. Increasingly, complete industrial systems are replacing old and obsolete equipment of the accelerators and technical services. Strategies are evolving to interface and progressively integrate Industrial Control Systems into the existing infrastructure. We present a status report of the Control System today and describe the current work to upgrade and prepare it for future applications in the LHC era

Summary and Recommendations from the Review of LTI and CNGS Controls held at CERN on July 10th, 2001

The Review of LHC Transfer lines and Injection (LTI) and CERN Neutrinos to Gran Sasso (CNGS) Controls was the first overview of requirements and preparations for the control of these facilities. Participants were asked to outline work that was already underway or planned in order to build an account of activities and responsibilities. The control of CNGS facilities downstream of the primary target was not included

Summary of the LHC Controls and Operations Forum held at CERN on 1-2 December 1999

The LHC Controls-Operations Forum in December attempted to identify the challenges of running the LHC and the implications for controls and equipment. An outline of the forum, its objectives, summaries of the various sessions, conclusions and some recommendations are presented. It is anticipated that this information will act as input into current and future development

LHC Communication Infrastructure: Recommendations from the working group

The LHC Working Group for Communication Infrastructure (CIWG) was established in May 1999 with members from the accelerator sector, the LHC physics experiments, the general communication services, the technical services and other LHC working groups. It has spent a year collecting user requirements and at the same time explored and evaluated possible solutions appropriate to the LHC. A number of technical recommendations were agreed, and areas where more work is required were identified. The working group also put forward proposals for organizational changes needed to allow the design project to continue and to prepare for the installation and commissioning phase of the LHC communication infrastructure. This paper reports on the work done and explains the motivation behind the recommendations

Dynamic Effects and their Control at the LHC

Tune, chromaticity and orbit of the LHC beams have to be precisely controlled by synchronising the magnetic field of quadrupole, sextupole and corrector magnets.This is a challenging task for an accelerator using superconducting magnets, whose field and field errors will have large dynamic effects.The accelerator physics requirements are tight due to the limited dynamic aperture and the large energy stored in the beams.The power converters need to be programmed in order to generate the magnetic functions with defined tolerances. During the injection process and the energy ramp the magnetic performance cannot be predicted with sufficient accuracy, and therefore real-time feedback systems based on magnetic measurements and beam observations are proposed. Beam measurements are used to determine a correction factor for some of the power converters. From magnetic measurements the excitation of small magnets to compensate the sextupolar (b3) and decapolar (b5) field components in the dipole magnets will be derived. To meet these requirements a deterministic control system is envisaged

Macro-scale patterns in functional connectivity associated with ongoing thought patterns and dispositional traits

Complex macro-scale patterns of brain activity that emerge during periods of wakeful rest provide insight into the organisation of neural function, how these differentiate individuals based on their traits, and the neural basis of different types of self-generated thoughts. Although brain activity during wakeful rest is valuable for understanding important features of human cognition, its unconstrained nature makes it difficult to disentangle neural features related to personality traits from those related to the thoughts occurring at rest. Our study builds on recent perspectives from work on ongoing conscious thought that highlight the interactions between three brain networks - ventral and dorsal attention networks, as well as the default mode network. We combined measures of personality with state-of-the-art indices of ongoing thoughts at rest and brain imaging analysis, and explored whether this ‘tri-partite’ view can provide a framework within which to understand the contribution of states and traits to observed patterns of neural activity at rest. To capture macro-scale relationships between different brain systems, we calculated cortical gradients to describe brain organisation in a low dimensional space. Our analysis established that for more introverted individuals, regions of the ventral attention network were functionally more aligned to regions of the somatomotor system and the default mode network. At the same time, a pattern of detailed self-generated thought was associated with a decoupling of regions of dorsal attention from regions in the default mode network. Our study, therefore, establishes interactions between attention systems and the default mode network are important influences on ongoing thought at rest and highlights the value of integrating contemporary perspectives on conscious experience when understanding patterns of brain activity at rest