Task 2.4 on LHC Collective Effects Studies Requested info: Detailed workflow, including milestones, expected deliverables and delivery dates => See also https://espace.cern.ch/hilumi/wp2/task4/ SitePages/Home.aspx where all the info linked to Task 2.4 should be! Next steps Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 1 /8
COORDINATION (with reliable info on the web site etc.): Elias 4 SUB-TASKS: 2.4.1 (IMPEDANCE): Impedance and wake field calculations for new components of the upgrade options (including heat load computations) 2.4.2 (INSTABILITIES): Study of the instabilities induced by impedance (without and with space charge) and electron cloud (including the associated heat load) for the different beam parameters and optics. Estimate in particular the required settings for the corrector circuits (chromaticity and Landau damping octupoles), transverse feedback and long. emittance blow-up 2.4.3 (IBS): Estimate the Intra Beam Scattering (IBS) growth rates for the different beam parameters and optics 2.4.4 (Other Mitigation measures): New 800 MHz RF system and proposals for beam/lattice manipulations to increase the LHC performance, such as flattening of the longitudinal distribution, change of the shape of the beam spectrum and/or reduction of side lobes (if needed for instance for the RF heating), use of circular optics, etc. Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 2 /8
MILESTONES MS29: Initial estimate of machine impedance (month 24: 01.11.2013) MS30: Initial estimates of intensity limitations (month 30: 01.05.2014) DELIVERABLE D2.4&2.6: Collective effects beam intensity limitations [report: Beam intensity limitations & Specification of machine and beam parameters, month 36 => 01/11/2014] Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 3 /8
2.4.1 (IMPEDANCE) Participants Mikhail Zobov, David Alesini, Alessandro Gallo, Bruno Spataro Mauro Migliorati, Luigi Palumbo, Andrea Mostacci Oliver Boine-Frankenheim, Uwe Niedermayer, Paul Görgen Rainer Wanzenberg, Olga Zagorodnova Alexey Burov Benoit Salvant, Fritz Caspers, Hugo Day Work packages Crab and RF cavities: Mikhail + David + Alessandro + Bruno + Alexey Collimators, MKI (injection kicker), TDI (injection dump): Benoit + Hugo Equipments with RF fingers: Elias (2012 LRFF Task Force) + Fritz Experimental beam pipes: Rainer + Olga Experimental areas (TAN Y-chamber etc.): Bruno Beam screen (weld, a-c coating to replace it, etc.): Mauro + Luigi + Andrea Others: electron lens, beam-beam compensation wires, (Roman pots), etc.?: Oliver + Uwe + Paul +? Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 4 /8
2.4.2 (INSTABILITIES) Participants Mikhail Zobov, David Alesini, Alessandro Drago, Alessandro Gallo, Fabio Marcellini + 1 fellow (still to be hired) Mauro Migliorati, Luigi Palumbo, Andrea Mostacci Oliver Boine-Frankenheim, Uwe Niedermayer, Paul Görgen Alexey Burov Nicolas Mounet, Elena Shaposhnikova, Wolfgang Hofle, Giovanni Rumolo, Frank Zimmermann Work packages TCBI & TMCI and requirements on chromaticities (1 st and 2 nd ) and octupoles (at injection and top energy): Nicolas Space charge effects on instabilities: Alexey + Nicolas + Oliver ADT (transverse feedback => damping; noise; emitt. BU etc.): Wolfgang Longitudinal instabilities and blow-up: Elena + Mauro + Luigi + Andrea Ecloud: Frank + Giovanni + Oliver + Uwe + Paul Ecloud suppression with clearing electrode and ecloud wideband feedback and MDs: Mikhail + David + AlessandroD + AlessandroG + Fabio + 1 fellow + Wolfgang Impedance, chromaticities (1 st and 2 nd ), ADT, octupoles and beam-beam :? Others? Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 5 /8
2.4.3 (IBS) Participants Deepa Angal-Kalinin Oliver Boine-Frankenheim, Uwe Niedermayer, Paul Görgen Alessandro Vivoli John Jowett, Michel Martini Work packages IBS: John + Deepa + Michel + Oliver + Uwe + Paul + Alessandro => Detailed sharing still to be discussed (vs. layouts to be considered, vs. codes etc.) Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 6 /8
2.4.4 (OTHER MITIGATION MEASURES): Participants Mikhail Zobov, David Alesini, Alessandro Gallo Alexey Burov Elena Shaposhnikova Work packages 800 MHz RF cavity: Elena + Mikhail + David + Alessandro Shaping of the longitudinal distribution: Elena + Alexey Circular modes: Alexey The 800 MHz RF cavity can be used either to have more Landau damping or to reduce the bunch length as we know we cannot simply reduce the bunch length by reducing the longitudinal emittance as the IBS becomes too strong => If we want at some point to reduce the bunch length we need to (maybe reduce slightly the emittance but then) add more voltage with the 800 MHz RF cavity => This is a very important item for HiLumi and we should really look at it asap! Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 7 /8
Elias will send an email (this evening ) to the HiLumi WP2 Task 2.4 members list (HI-LUMI-FP7-WP2-TASK-2.4) to Inform them of / validate the current WBS (this talk) Invite all the members to an EVO meeting next week (or the week after) to discuss all this together, approve it and start (continue) the work! Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 8 /8