| Paper | Title | Page |
|---|---|---|
| MOCP03 | Status of the LHC | 44 |
|
||
| For the LHC to provide particle physics with proton-proton collisions at a centre of mass energy of 14 TeV with a luminosity of 1034 cm-2s-1, the machine will operate with high-field dipole magnets using NbTi superconductors cooled to below the λ point of helium. The construction follows a decade of intensive R&D and technical validation of major collider sub-systems. Installation of the accelerator system is in full swing. Commissioning of the injector complex is well advanced, including beam transfer through one of the transfer lines from SPS to LHC. In the LHC machine, commissioning of the cryogenic system and powering system has started. The status of the LHC accelerator and a brief outlook to operation and its consequences for the machine protection systems will be given. The strategy for the machine protection and beam cleaning will have a major impact on commissioning and operation since each of the two LHC proton beam has a stored energy of about 360 MJ. A fraction of less than 10-3 of the full beam threatens to damage accelerator equipment in case of uncontrolled beam loss, and only 10-8 protons could already quench a magnet. | ||
| WEAZ07 | Shock wave propagation near 7 TeV proton beam in LHC collimator materials | 241 |
|
||
|
A study is presented to estimate the influence of the impact of a 7 TeV proton beam on the physical-mechanical material properties, such as C for collimators, and Cu elsewhere. The high energy stored in each bunch can produce a shock wave near the impacting proton beam in these materials. The theoretical model for the investigations of shock wave propagation in the collimator materials takes into account ionization, electronic excitation, and energy transfer from excited electronic subsystem in the materials to the ionic subsystem. The change of other physical properties of the material is also considered. The deposited energy is calculated with FLUKA [1]. The numerical results of the microstructure change in the material are presented for different numbers of bunches. The method allows investigating changes of density and internal pressure, the distributions of atomic and sound velocities, and the temperature profiles in electronic and ionic subsystems of materials near the front of shock wave. These results are very relevant for the understanding the behavior of collimator materials used in LHC under 7 TeV proton beam.
[1] A. Fasso et al. The physics models of FLUKA: status and recent development, CHEP 2003, LA Jolla, California, 2003 |
||
| THAZ03 | Safe LHC Beam Commissioning | 306 |
|
||
| 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. | ||
| FRAP03 | Summary of Working Group C+G (Part I) | 365 |
|