Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 /8 1

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 /8 2

  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 /8 3

  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 /8 4

  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 /8 5

  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 (1st and 2nd) 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 (1st and 2nd), ADT, octupoles and beam-beam…: ? Others?

Elias Métral, 3rd HiLumi WP2 Task Leaders Meeting, CERN, 29/03/2012 /8 6

  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 /8 7

  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 /8 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!