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| THAZ01 |
Experience with high-power operation of the PSI proton accelerator facility
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274 |
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- P. A. Schmelzbach
PSI, Villigen
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The PSI proton accelerator delivers a maximun current of 2 mA (routinely 1.9 mA) at 590 MeV. Ongoing developments aim at an upgrade of the beam current to 3 mA. This will result in an increase of the beam power from 1.2 to 1.8 MW on the pion/muon production targets and from 0.8 to 1.2 MW on the neutron spallation source SINQ. Our approach to the safe operation of a facility a these power levels will be presented. This includes considerations on the design of the cyclotrons, the beam lines and the tools to handle highly radioactive components. The protection of the facility via device controls, beam diagnostics and loss monitoring will be discussed. The specific requirements for operation with a sensitive liquid metal target like MEGAPIE will also be addressed.
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| THAZ02 |
SNS Commissioning Strategies and Tuneup Algorithms
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283 |
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- J. Galambos
ORNL, Oak Ridge, Tennessee
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The Spallation Neutron Source (SNS) has been recently commissioned. The strategies for the initial beam commissioning of the superconducting linac (SCL) and storage ring will be discussed. The SCL commissioning had to accommodate an unanticipated wide range of cavity performance, compared to design expectations. Methods for setting cavity phases and determination of amplitudes will be discussed. The ring commissioning involved the usual establishment of a circulating beam, and then measurement and correction the tune and beta functions, all with a low intensity beam. Then the gradual increase of beam intensity and commissioning of RF and phase space painting were investigated. The methods to accomplish these tasks will be discussed. In general, the first order beam behavior is well understood. Key factors in the successful commissioning are: flexibility in accommodating beam conditions that are different from the design, good communication between the different groups, and attention to detail. Examples for these factors will be emphasized.
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| THAZ03 |
Safe LHC Beam Commissioning
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306 |
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- J. A. Uythoven, R. Schmidt
CERN, Geneva
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Due to the large amount of energy stored in magnets and beams, safe operation of the LHC is essential. The commissioning of the LHC machine protection system will be an integral part of the general LHC commissioning program. A brief overview of the LHC Machine Protection System will be given, identifying the main components: the Beam Interlock System, the Beam Dumping System, the Collimation System, the Beam Loss Monitoring system and the Quench Protection System. An outline is given of the commissioning strategy of these systems during the different commissioning phases of the LHC: without beam, injection and the different phases with stored beam depending on beam intensity and beam energy.
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| THAZ04 |
Commissioning and Operational Scenarios of the LHC Beam Loss Monitor System
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314 |
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- E. B. Holzer
CERN, Geneva
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One of the most critical elements for the protection of CERN’s Large Hadron Collider (LHC) is its beam loss monitoring (BLM) system. It aims to prevent the super conducting magnets from quenching and to protect the machine components from damages, as a result of critical beam losses. The contribution will discuss the commissioning procedures of the BLM system and the envisaged operational scenarios. About 4000 monitors will be installed around the ring. The specification for the BLM system includes a factor of 2 absolute precisions on the prediction of the quench levels, a wide range of integration times (100 us to 100 s) and a fast (one turn) trigger generation. When the loss rate exceeds a pre-defined threshold value, a beam abort is requested. Magnet quench and damage levels vary as a function of beam energy and loss duration. Consequently, the beam abort threshold values vary accordingly. By measuring the loss pattern, the BLM system helps to identify the loss mechanism. Furthermore, it will be an important tool for commissioning, machine setup and studies. Special monitors will be used for the setup and control of the collimators.
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| THAZ05 |
Beam Loss Management and Machine Protection in Beam Commissioning
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0 |
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- C. Sibley, J. Galambos
ORNL, Oak Ridge, Tennessee
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Machine Protection Systems during commissioning have to be very reliable and flexible. The consequence of not disabling the beam could be catastrophic in terms of the superconducting cavities or High Power mercury targets. On the other hand, as the machine is commissioned the beam parameters are being measured which in turn causes beam loss so losses are unavoidable. One commissioning activity involves fault studies where worst case beam loss scenarios are investigated and radiation in occupied area’s is measured and verified to be with the safety limits when extracted to full power. The beam loss monitor system also gets calibrated during these studies. These activities require flexibility in the system to be able to bypass MPS inputs while maintaining strict configuration control over the MPS hardware and software systems.
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| THAZ06 |
Commissioning scenarios for the J-PARC accelerator complex
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329 |
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The J-PARC accelerator complex consists of a 400-MeV linac, a 3.0-GeV rapid-cycling synchrotron (RCS), a 50-GeV main ring (MR) and associated beam transport lines to experimental facilities, which use the 3- and 50-GeV proton beams. It is now under construction in the Tokai campus of JAEA as a joint project between JAEA and KEK. The beam commissioning of each accelerator is scheduled to start for linac in December 2006, RCS in September 2007 and MR in May 2008. The commissioning strategy for the accelerator complex will be presented.
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