CERN Accelerating science

Internal Note
Report number	CERN-ACC-NOTE-2019-0057
Title	Beam-induced heat loads on the LHC arc beam screens with different beam and machine configurations: experiments and comparison against simulations
Author(s)	Iadarola, Giovanni (CERN) ; Skripka, Galina (Joint Institute for Nuclear Research (RU)) ; Albert, Markus (CERN) ; Amorim, David (Universite Grenoble-Alpes (FR)) ; Andujar, Oscar (CERN) ; Antipov, Sergey (CERN) ; Arduini, Gianluigi (CERN) ; Argyropoulos, Theodoros (CERN) ; Bradu, Benjamin (CERN) ; Bartosik, Hannes (CERN) ; Bracco, Chiara (CERN) ; Crockford, Guy (CERN) ; Damerau, Heiko (CERN) ; De Maria, Riccardo (CERN) ; Di Giovanni, Gian Piero (CERN) ; Dumont, Jean-Charles (CERN) ; Fartoukh, Stephane (CERN) ; Follin, Fabio (CERN) ; Fuchsberger, Kajetan ; Fuster Martinez, Nuria (CERN) ; Giordano, Francesco (Universita e sezione INFN di Napoli (IT)) ; Hemelsoet, Georges-Henry (CERN) ; Jaussi, Michael (CERN) ; Kain, Verena (CERN) ; Kolbeck, Luciana (CERN) ; Komppula, Jani Paavo Olavi ; Le Borgne, Yannick (CERN) ; Li, Kevin Shing Bruce (CERN) ; Maclean, Ewen Hamish (University of Malta (MT)) ; Mether, Lotta (CERN) ; Metral, Elias (CERN) ; Papotti, Giulia (CERN) ; Paraschou, Konstantinos (Aristotle University of Thessaloniki (GR)) ; Persson, Tobias Hakan Bjorn (CERN) ; Redaelli, Stefano (CERN) ; Romano, Annalisa ; Rumolo, Giovanni (CERN) ; Sabato, Luca (CERN) ; Salvachua Ferrando, Belen Maria (CERN) ; Salvant, Benoit (CERN) ; Schaumann, Michaela (CERN) ; Chapochnikova, Elena (CERN) ; Soderen, Martin (CERN) ; Solfaroli Camillocci, Matteo (CERN) ; Suykerbuyk, Ronaldus (CERN) ; Sveen, Ole Gunnar (CERN) ; Tavian, Laurent Jean (CERN) ; Teofili, Lorenzo (Sapienza Universita e INFN, Roma I (IT)) ; Timko, Helga (CERN) ; Tomas Garcia, Rogelio (CERN) ; Trad, Georges (CERN) ; Uythoven, Jan (CERN) ; Uznanski, Slawosz (CERN) ; Valuch, Daniel (CERN) ; Velotti, Francesco Maria (CERN) ; Walsh, David John (CERN) ; Wenninger, Jorg (CERN) ; Wulff, Eric (Lund University (SE))
Corporate author(s)	CERN. Geneva. ATS Department
Publication	2019
Imprint	20 Dec 2019
Number of pages	50
Subject category	Accelerators and Storage Rings
Accelerator/Facility, Experiment	CERN LHC
Keywords	LHC ; arcs ; heat load ; electron cloud ; MD2484 ; MD3295 ; MD3296 ; MD3297 ; MD3298 ; MD3300 ; MD4203
Abstract	Electron cloud (e-cloud) effects are among the main performance limitations for the operation of the Large Hadron Collider (LHC) with 25 ns bunch spacing. A large number of electrons impacting on the beam-screens of the superconducting magnets induces significant heat load, reaching values close to the full cooling capacity available from the cryogenic system. A number of Machine Development (MD) sessions in 2018 was dedicated to characterizing the heat load as a function of beam and machine parameters, investigating in particular its distribution along the ring and its dependence on the filling pattern, bunch population and bunch length. The main results of these measurements have been compared against simulations performed with the PyECLOUD code in order to validate the underlying model.
Submitted by	alessia.valenza@cern.ch