A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Raimondi, S.

Paper Title Page
MOPAN026 Critical Issues in Ensuring Reproducible and Reliable Deposition of NEG Coatings for Particle Accelerators 209
  • A. Bonucci, A. Conte, P. Manini, S. Raimondi
    SAES Getters S.p. A., Lainate
  Non Evaporable getter (NEG) coating technology, developed at CERN in the late 90s, is an effective pumping solution for conductance limited vacuum chambers. It reduces thermal out-gassing and provides distributed pumping ability, allowing the achievement of very low pressure. NEG films do show additional interesting features, like low secondary electron yield and low gas de-sorption rates under ions, electrons and photons bombardment. For these reasons, large scale adoption of NEG coated chambers is now a reality and several leading edge machines will soon benefit from it. A critical issue for the successful application of this technology is the ability to deposit NEG coatings in a reproducible and reliable way all along a pipe. This is particularly important for narrow-gap or specially shaped chambers which pose severe challenges in term of film thickness distribution, chemical composition and sorption properties. A dedicated study was carried out to fully understand the deposition process as a function of the sputtering parameters and the chamber geometry. Results obtained do allow to optimize the coating process and ensure that film requirements in a given application are met.  
MOPAN027 NEG Coating of Pipes for RHIC : An Example of Industrialization Process 212
  • A. Conte, A. Bonucci, P. Manini, S. Raimondi
    SAES Getters S.p. A., Lainate
  Non Evaporable Getter (NEG) coated chambers have been used in various accelerators facilities and synchrotrons since some years. Initially, NEG coated chambers were mounted in small amounts in specific locations, covering a minor fraction of the accelerator surfaces exposed to vacuum. More recently, NEG coated chambers have been adopted to a larger degree in several projects, becoming an integral part of the machine design. LHC, whose commissioning is expected in 2007, will use 6 km of coated pipes, to be the largest machine ever using this technology. Other examples are the Soleil synchrotron (50% of the ring is NEG coated), ESRF (ongoing replacement of ID with NEG coated chambers) and RHIC (installation of 600 m of NEG coated pipes ongoing).Coating a large number of chambers poses challenges in term of process industrialization, product inspection and quality assurance. In the present paper we report SAES Getters' experience in the NEG coating of pipes delivered to Brookhaven National Lab for RHIC(120 steel chambers, each 5 m long). Main technological issues faced and procedures adopted to ensure product reproducibility and quality are presented and discussed.