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TY - CONF AU - Leber, R. AU - Caspers, F. AU - Costa Pinto, P. AU - Taborelli, M. ED - Henderson, Stuart ED - Akers, Evelyn ED - Satogata, Todd ED - Schaa, Volker R.W. TI - Reduction of Electron Cloud in Particle Accelerator Beampipes Studied by RF Multipacting J2 - Proc. of IPAC2015, Richmond, VA, USA, May 3-8, 2015 C1 - Richmond, VA, USA T2 - International Particle Accelerator Conference T3 - 6 LA - english AB - For a given beam structure, chamber geometry and magnetic field configuration, the electron cloud (EC) intensity depends on the Secondary Electron Yield (SEY) of the beam pipe. The reduction of the EC density as a function of machine operation time (scrubbing) is attributed to the growth of a low SEY carbon film induced by electron bombardment. In this paper, we study the time evolution of the conditioning of stainless steel beam pipes in a laboratory setup. The EC or multipacting is induced by Radio-Frequency (RF) fields in a coaxial resonator under vacuum. Strip detectors are used to monitor the current of the EC. Induced pressure rise is simultaneously detected. The multipacting intensity shows a linear dependence on the positive DC bias voltage up to 1000 V, applied to the central electrode. An accelerated conditioning is observed for the applied bias voltage. The SEY of samples exposed to the EC is measured and the surface composition is monitored by X-ray Photoelectron Spectroscopy. The measured SEY, surface composition and multipacting behaviour are well correlated. The injection of acetylene and dodecane during multipacting proved to be ineffective in the conditioning. PB - JACoW CP - Geneva, Switzerland SP - 472 EP - 475 KW - electron KW - injection KW - vacuum KW - detector KW - network DA - 2015/06 PY - 2015 SN - 978-3-95450-168-7 DO - 10.18429/JACoW-IPAC2015-MOPJE070 UR - http://jacow.org/ipac2015/papers/mopje070.pdf ER -