[en] This report catalogues approved experiments at CERN and has been compiled as a guide to the status of the experimental research programme at the 400 GeV Proton Synchrotron (SPS), the Intersecting Storage Rings (ISR), the 25 GeV Proton Synchrotron (PS) and the Synchro-Cyclotron (SC). The schematic layouts of beams and experiments at the various machines are given in the beginning of the report and are followed by descriptive material on the experiments. In general, a short summary of each of the approved experiments is given with a description of the physics purpose, the apparatus employed, a list of the participants and the name of the collaboration. (Auth.)

[en] On the occasion of the celebrations being held in Geneva to mark the 25th Anniversary of CERN the achievements and successes of Europe's centre for research in nuclear physics are considered. The facilities available to European high-energy nuclear physicists at CERN, the synchrocyclotron, the proton synchrotron, the intersecting storage rings and the super proton synchrotron, are described. It is felt that CERN has certainly fulfilled the intentions of its founders, showing that Europeans can work together and giving the community of particle physicists facilities second to none. (UK)

[en] The 1979 catalogue of approved experiments at CERN has been compiled as a guide to the status of the experimental research programme at the 400 GeV Proton Synchrotron (SPS), the Intersecting Storage Rings (ISR), the 25 GeV Proton Synchrotron (PS), and the Synchrocyclotron (SC). The schematic layouts of beams and experiments at the various machines are given in the beginning of the report and are followed by descriptive material on the experiments. In general, a short summary of each of the approved experiments is given, with a description of the physics purpose, the apparatus employed, a list of the participants and the name of the collaboration. (Auth.)

[en] The 1976 CERN annual report begins with a brief history of the organization and description of the organizational structure. A description of the CERN accelerators is given and CERN scientific activities are reviewed. The main body of the report comprises reports from the eleven main divisions, and administrative divisions such as personnel and finance. The reports from the scientific divisions contain descriptions of, and data from, present research and plans for long term development. The appendices contain a list of CERN publications for 1976, a list of lectures and seminars held, a list of training programmes undertaken and a list of scientific conferences and schools held. (B.D.)

[en] Several indicators have pointed to the presence of an Electron Cloud (EC) in some of the CERN accelerators, when operating with closely spaced bunched beams. In particular, spurious signals on the pick ups used for beam detection, pressure rise and beam instabilities were observed at the Proton Synchrotron (PS) during the last stage of preparation of the beams for the Large Hadron Collider (LHC), as well as at the Super Proton Synchrotron (SPS). Since the LHC has started operation in 2009, typical electron cloud phenomena have appeared also in this machine, when running with trains of closely packed bunches (i.e. with spacings below 150ns). Beside the above mentioned indicators, other typical signatures were seen in this machine (due to its operation mode and/or more refined detection possibilities), like heat load in the cold dipoles, bunch dependent emittance growth and degraded lifetime in store and bunch-by-bunch stable phase shift to compensate for the energy loss due to the electron cloud. An overview of the electron cloud status in the different CERN machines (PS, SPS, LHC) will be presented in this paper, with a special emphasis on the dangers for future operation with more intense beams and the necessary countermeasures to mitigate or suppress the effect. (author)

[en] The emergence of the ISR project at CERN is described in the light of the situation at CERN at the end of the 1950s when the CERN Proton Synchrotron (PS) was still under construction. The discussions leading to the project are put into context with world-wide efforts to build larger and more powerful accelerators at that time/ the evolution of the project before approval is sketched. The basic design considerations and the most significant technological choices are explained. The construction period is summarized by highlighting important milestones and the performance achieved during commissioning in 1971, the first year of running, is given

[en] The progress report is divided into two parts, for Laboratory I (basic and ISR programmes) and Laboratory II (300-GeV accelerator programme) respectively. In the first part, a general survey is given of the research results achieved in 1975 with the 28-GeV Proton Synchrotron and the Intersecting Storage Rings, as well as of corresponding theoretical and technological developments. More detailed accounts are given under Departmental and Divisional headings - Nuclear Physics, Synchrocyclotron Machine, Track Chambers, Theoretical Studies, Proton Synchrotron Machine, Data Handling, Intersecting Storage Rings, Finance, Personnel, Technical Services and Buildings, Health and Safety, and Central Services. The second part of the report describes the progress with the construction of the 300-400-GeV Super Proton Synchrotron. Organigrams of the Council and the two Laboratories, as well as a brief account of CERN's history, are included. Appendices provide a bibliography of CERN publications in 1975 and lists of lectures and seminars, training programmes, and scientific conferences and schools organized during the year. (AGH/AJ)

[en] Some information about the newest achievements with the accelerators at CERN is given

[en] The progress report is divided into two parts, for Laboratory I (basic and ISR programmes) and Laboratory II (300-GeV accelerator programme) respectively. In the first part, a general survey is given of the research results achieved in 1974 with the 28-GeV Proton Synchrotron and the Intersecting Storage Rings, as well as of corresponding theoretical and technological developments. More detailed accounts are given under Departmental and Divisonal headings - Nuclear Physics, Synchrocyclotron Machine, Track Chambers, Theoretical Studies, Proton Synchrotron Machine, Data Handling, Intersecting Storage Rings, Finance, Personnel, Technical Services and Buildings, Health Physics, General Safety, and Central Services. The second part of the report describes the progress with the construction of the 300-400-GeV Super Proton Synchrotron. Organigrams of the Council and the two Laboratories, as well as a brief account of CERN's history, are included. Appendices provide a bibliography of CERN publications in 1974 and lists of lectures and seminars, training programmes, and scientific conferences and schools organized during the year. (AGH/AJ)

[en] Review of 2011 LHC Run from The Experiments Perspective, M. Ferro-Luzzi (PH-LBD): M. Ferro-Luzzi highlighted the excellent performance of the machine and the experiments in 2011 and the fast and impressive achievements both when operating with protons and Pb ions. In a month the same luminosity as during the full 2010 proton run was delivered, and a factor 16 higher luminosity was produced with Pb ions. The excellent machine performance allowed ATLAS and CMS to make interesting observations in the context of the Higgs’ boson search and LHCb found some evidence of CP violation in time-integrated D0 which could open the way for a new physics. Input from Evian, M. Lamont (BE-OP): M. Lamont presented a summary of what discussed in Evian about lessons learnt during 2011 operation and improvements foreseen for 2012. He underlined that 2011 was a remarkable year with a continuously faster increase in luminosity production and without real show stoppers. The machinewas characterized by operational robustness, a good reproducibility, stability, beam lifetime, optics control and an excellent performance of the Machine Protection system (MPs) and of the injectors. The 2011 Run: Availability Analysis, A. Macpherson (BE-OP): A. Macpherson spoke about machine availability in 2011 and gave some statistics of fills for p-p and Pb-Pb runs. He calculated a machine availability of 76.7% and that 33% of the operation time was spent in stable beam. The Hubner factor, which gives an estimate of the luminosity production duration, was slightly bigger than the expected 0.2 value both for the proton (0.22) and lead ion (0.24) runs. Stable beams lasted in average ∼6 hours but about 50% of the fills were shorter than 4 hours. Injection and Lessons for 2012, C. Bracco (TE-ABT): C. Bracco made a presentation on the performance of the injection system. The injection of 144 bunches became fully operational in 2011 in agreement with what predicted during the last Chamonix workshop. Moreover 288 bunches could be injected, during MD time, for both beams with a good margin between the losses and the BLM dump thresholds. Improvements are still needed to optimize the 25 ns beam in the injector chain and accumulate it in the LHC with a good lifetime; the results are encouraging in view of operation with the designed intensity. Machine Protection, M. Zerlauth (TE-MPE): M. Zerlauth introduced the architecture of the LHC Machine Protection System (MPS). He explained that this is a complex system that checks more than 10000 interlock conditions and has to evolve to follow operational changes, special runs and MD requirements. Vacuum Performance and Lessons for 2012, V. Baglin (TE-VSC): V. Baglin presented a talk on the main vacuum observations made in 2011: dynamic effects induced by the circulating beam (synchrotron radiation and e-clouds) and unexpected local pressure spikes. He explained that the desorption yield in the cold-warm transitions was much worse (factor 50) than in the warm-warm transition due to gas load from the cold part. Emittance Preservation, V. Kain (BE-OP): V. Kain spoke about emittance preservation all along the injectors chain up to collisions in the LHC. She explained that injectors behaved extremely well in 2011 and, for the 50 ns beams and a bunch population higher than nominal, an emittance blowup of 0.4 μm was measured from the PS to the SPS (from design report: 0.5 μm were estimated for 25 ns beams). On the other hand a 20-30% emittance growth is observed between the SPS flattop and LHC collisions. Several methods are used for emittance measurements (wire scanner, BSRT and luminosity) and all methods present some limitations. Moreover measurements in the SPS and in the LHC are not synchronized and refer to different beams.