2008 JINST 3 S08001 9.3.1 The VME and PC Front End Computers 9.3.2 The PLCs 9.3.3 The supported fieldbuses 9.3.4 The WorldFIP fieldbus 9.3.5 The Profibus fieldbus 9.4 Servers and operator consoles 9.5 Machine timing and UTC 9.5.1 Central beam and cycle management 9.5.2 Timing generation, transmission and reception 9.5.3 UTC for LHC time stamping 9.5.4 UTC generation, transmission and reception 9.5.5 NTP time protocol 9.6 Data management 9.6.1 Offline and online data repositories 9.6.2 Electrical circuits 9.6.3 Control system configuration 9.7 Communication and software frameworks 9.7.1 FEC software framework 9.7.2 Controls Middleware 9.7.3 Device access model 9.7.4 Messaging model 9.7.5 The J2EE framework for machine control 9.7.6 The UNICOS framework for industrial controls 9.7.7 The UNICOS object model 9.8 Control room software 9.8.1 Software for LHC beam operation 9.8.2 Software requirements 9.8.3 The software development process 9.8.4 Software for LHC Industrial Systems 9.9 Services for operations 9.9.1 Analogue signals transmission 9.9.2 Alarms 9.9.3 Logging 9.9.4 Post mortem 10 Beam dumping 10.1 System and main parameters 13 LHC as an ion collider 13.1 LHC parameters for lead ions 13.1.1 Nominal ion scheme 13.1.2 Early ion scheme 13.2 Orbits and optical configurations for heavy ions 13.3 Longitudinal dynamics 13.4 Effects of nuclear interactions on the LHC and its beams 13.5 Intra-beam scattering 13.6 Synchrotron radiation from lead ions LHC machine acronyms Bibliography-vi-2008 JINST 3 S08001 Chapter 1 2008 JINST 3 S08001 2.2.7 Collective beam instabilities The interaction of the charged particles in each beam with each other via electromagnetic fields and the conducting boundaries of the vacuum system can result in collective beam instabilities. Generally speaking, the collective effects are a function of the vacuum system geometry and its surface properties. They are usually proportional to the beam currents and can therefore limit the maximum attainable beam intensities. 2.2.8 Luminosity lifetime The luminosity in the LHC is not constant over a physics run, but decays due to the degradation of intensities and emittances of the circulating beams. The main cause of the luminosity decay during nominal LHC operation is the beam loss from collisions. The initial decay time of the bunch intensity, due to this effect, is:

This book is a basic introduction to the principles of circular particle accelerators and storage rings, for scientists, engineers and mathematicians. Particle accelerators used to be the exclusive province of physicists exploring the structure of the most fundamental constituents of matter. Nowadays, particle accelerators have also found uses as tools in many other areas, including materials science, chemistry, and medical science. Many people from these fields of study, as well as from particle physics, have learned about accelerators at various courses organised by CERN, the European Organisation for Nuclear Research which has established a reputation as the world's top accelerator facility. Kjell Johnsen and Phil Bryant, the authors of this book, are distinguished accelerator physicists who have also run the CERN Accelerator School. The text they present here starts with a historical introduction to the field and an outline of the basic concepts of particle acceleration and phase focusing. It goes on to give more details of how the transverse and longitudinal motions of the particle beams can be analysed, including treatments of lattice design, compensation schemes, transition crossing, and other radio frequency effects. The book will be an essential reference to anyone working with particle accelerators as a designer, operator or user, as well as being a good preparation for those intending to go to the frontiers of accelerator physics.

The Proton-Ion Medical Machine Study (PIMMS) was set up following an agreement between Professor M. Regler of the Med-AUSTRON (Austria) and Professor U. Amaldi of the TERA Foundation (Italy) to join their efforts in the design of a medical synchrotron that could later be adapted to individual national needs. CERN agreed to host this study inside its PS Division and to contribute one full-time member to the study team. The study group has worked in collaboration with GSI (Germany) and was more recently joined by Onkologie 2000 (Czech Republic). Work started in January 1996 and is expected to finish during 1998. The agreed aim of the study was to investigate and design a generic facility that would allow the direct clinical comparison of protons and carbon ions for cancer treatment. The accelerator was to be designed primarily for high-precision active beam scanning with both protons and ions, but was also to be capable of delivering proton beams with passive spreading.

The treatment of cancer with accelerator beams has a long history with linacs, cyclotrons and now synchrotrons being exploited for this purpose. Treatment techniques can be broadly divided into the use of spread-out beams and scanned 'pencil' beams. The Bragg-peak behaviour of hadrons makes them ideal candidates for the latter. The combination of precisely focused 'pencil' beams with controllable penetration (Bragg peak) and high, radio-biological efficiency (light ions) opens the way to treating the more awkward tumours that are radioresistant, complex in shape and lodged against critical organs. To accelerate light ions (probably carbon) with pulse-to-pulse energy variation, a synchrotron is the natural choice. The beam scanning system is controlled via an on-line measurement of the particle flux entering the patient and, for this reason, the beam spill must be extended in time (seconds) by a slow-extraction scheme. The quality of the dose intensity profile ultimately depends on the uniformity of the beam spill. This is the greatest challenge for the synchrotron, since slowextraction schemes are notoriously sensitive. This paper reviews the extraction techniques, describes methods for smoothing the beam spill and outlines the implications for the extraction line and beam delivery system.