Jimenez, J. M.

Paper	Title	Page
TUPC037	Development, Production and Testing of 4500 Beam Loss Monitors	1134
	E. B. Holzer, P. Chiggiato, B. Dehning, G. Ferioli, V. Grishin, J. M. Jimenez, M. Taborelli, I. Wevers CERN, Geneva A. Koshelev, A. Larionov, V. Seleznev, M. Sleptsov, A. Sytin IHEP Protvino, Protvino, Moscow Region D. K. Kramer TUL, Liberec
	Beam-loss monitoring (BLM) is a key element in the LHC machine protection. 4250 nitrogen filled ionization chambers (IC) and 350 secondary emission monitors (SEM) have been manufactured at the Institute for High Energy Physics (IHEP) in Protvino, Russia, following their development at CERN. Signal speed and robustness against ageing were the main design criteria. Each monitor is permanently sealed inside a stainless-steel cylinder. The quality of the welding was a critical aspect during production. The SEMs are requested to hold a vacuum of 1·10-7 bar. Impurity levels from thermal and radiation-induced desorption should remain in the range of parts per million in the ICs. The difference in sensitivity is about 3·104. To avoid radiation aging (up to 2·108 Gy in 20 years) production of the chambers followed strict UHV requirements. IHEP designed and built the UHV production stand. Due to the required dynamic range of 1·109, the leakage current of the monitors has to stay below 1 pA. Several tests during and after production were performed at IHEP and CERN. A consistently high quality during the whole production period was achieved and the tight production schedule kept at the same time.
WEOBM04	LHC: The World's Largest Vacuum Systems being Commissioned at CERN	1959
	J. M. Jimenez CERN, Geneva
	When it switches on in the spring of 2008, the 26.7 km Large Hadron Collider (LHC) at CERN, will have the world's largest vacuum system operating over a wide range of pressures and employing an impressive array of vacuum technologies. This system is composed by 54 km of UHV vacuum for the circulating beams and 24 km of insulation vacuum around the cryogenic magnets operated mainly at 1.9 K. Over the 54 km of UHV beam vacuum, 48 km of this must be at cryogenic temperature (1.9 K). The remaining 6 km of beam vacuum containing the insertions is at ambient temperature and uses non-evaporable getter (NEG) coatings – a vacuum technology that was born and industrialized at CERN. The pumping is completed using 600 ion pumps to remove noble gases and 1000 gauges are used to monitor the pressures. The cryogenic insulation vacuum, while technically less demanding, is impressive by its size - 24 km in length, 900 mm in diameter for a total volume of 640 m3. Once cooled at 1.9 K, the cryogenic pumping allows reaching pressure in the 10-6 mbar range. This paper described the entire vacuum system and the challenges of the design, manufacturing, installation and commissioning phases.
	Slides
WEPP009	Collimator Integration and Installation Example of One Object to be Installed in the LHC	2542
	K. Foraz, O. Aberle, R. W. Assmann, C. Bertone, R. Chamizo, S. Chemli, J.-P. Corso, F. Delsaux, J. L. Grenard, J. M. Jimenez, Y. Kadi, K. Kershaw, M. Lazzaroni, R. Perret, Th. Weiler CERN, Geneva J. Coupard IN2P3-CNRS, Orsay
	The collimation system is a vital part of the LHC project, protecting the accelerator against unavoidable regular and irregular beam loss. About 80 collimators will be installed in the machine before the first run. Two insertion regions are dedicated to collimation and these regions will be among the most radioactive in the LHC. The space available in the collimation regions is very restricted. It was therefore important to ensure that the 3-D integration of these areas of the LHC tunnel would allow straightforward installation of collimators and also exchange of collimators under the remote handling constraints imposed by high radiation levels. The paper describes the 3-D integration studies and verifications of the collimation regions combining the restricted space available, the dimensions of the different types of collimators and the space needed for transport and handling. The paper explains how installation has been planned and carried out taking into account the handling system and component availability.
THPP138	Achievement and Evaluation of the Beam Vacuum Performance of the LHC Long Straight Sections	3685
	G. Bregliozzi, V. Baglin, S. Blanchard, J. Hansen, J. M. Jimenez, K. Weiss CERN, Geneva
	The bake-out and activation of the 6 km Long Straight Sections (LSS) of the Large Hadron Collider (LHC) is in its final step. After bake-out and activation of the NEG coating, the average ultimate pressure, over more than one hundred vacuum sectors, is below 10-11 mbar. Therefore, the nominal requirement for the four experimental insertions is guaranteed. The nominal performances are also ensured for all the other insertions where collimators, RF cavities and beam dumping systems are present. The main difficulties encountered during the bake-out and activation of NEG coated chambers of the LSS vacuum sectors will be presented and discussed. In particular, the acceptance test and the limiting factors of the reached ultimate pressures will be addressed. Furthermore, the influence on the ultimate pressures of the beam vacuum elements (collimators, beam instrumentation, etc.) will be discussed. Finally, preliminary results obtained from a laboratory NEG pilot sector dedicated to the quality control of the LHC beam vacuum and to the evaluation of the NEG performance will be presented.