Pending RLC Actions
transverse impedance items where urgent answers were/are needed
| action | date | in charge | priority | status |
| get MAFIA input files & understand boundary conditions used for Y Chamber | 28.11.2006 | EM | high | DONE, LCU 26.02.2007 |
| follow up of GSI resistive-wall impedance result | 07.07.2006 | EM | high | IN PROGRESS, 19.09.2006, 26.09.2006, 24.10.2006 |
| follow-up impedance of LHC septa | 07.04.2006 | EM | high | TO BE FOLLOWED UP |
| contact D. Macina to organize meeting with experiments on TCTV aperture | 17.03.2006 | FR | highest | addressed by RLC discussion on 07.04.2006, CLOSED LCU 26.02.2007 (RA) |
| contact M. Mayer to question chamber dimensions | 17.03.2006 | EM, AG | highest | CLOSED LCU 26.02.2007 (RA) |
| check whether a reduction of transverse dimensions of TCTV vacuum chamber is compatible with Totem Roman Pots requirements. |
10.03.2006 | FR | high | CLOSED LCU 26.02.2007 (RA) |
| compute collimation performance and loss maps with 2 m beta-star at IP2 and IP8 and larger TCTV gaps |
17.02.2006 | RA, TW | high | CLOSED LCU 26.02.2007 (RA) |
| final impedance of TDI | 03.02.2006 | AG | medium | TO BE FOLLOWED UP |
| compare collimator bench measurements with HFSS simulation | 08.07.2005 | AG | low | ON HOLD, OR TO BE FOLLOWED U P |
| compare the size of the longitudinal geometric wake with RW longitudinal wake from A. Koschik | 28.01.2005 | FR | medium | TO BE FOLLOWED UP |
electron-cloud effects (mostly incoherent)
| action | date | in charge | priority | status |
| discuss MAD-X e-cloud module with Frank Schmidt | 05.12.2006 | FZ | high | PLANNED |
| discuss US-LARP contribution to incoherent e-cloud studies with Wolfram Fischer (and Mauro Pivi) | 05.12.2006 | OB | high | PLANNED |
| organize meeting with L. Tavian and write a note on e- cloud | 03.02.2006 | FR, FZ et al | high | Meeting with L. Tavian DONE 17.02.2006 by FR, note PLANNED |
| review or prediction of incoherent electron-cloud effects in the LHC. | 11.11.2005 | FZ, EB-> GR | high | PLANNED, task reassigned 03.02.2006 |
| prediction of beam lifetime and emittance growth as a function of density for the LHC and SPS based on HEADTAIL simulations for a dipole field | 10.06.2005 | EB -> GR, FZ | high | Task re-assigned 03.02.2006, DONE for LHC by EB on 03.03.2006 |
beam-beam
| action | date | in charge | priority | status |
| simulate conditions of SPS compensation experiment(s) | 08.07.2005 | UD | high | ONGOING |
| estimate stabilization by beam-beam for injection conditions | 24.06.2005 | WH | medium | CALCULATIONS DONE (LCU 26.02.2007), DOCUMENTATION PLANNED |
injectors
| action | date | in charge | priority | status |
| review predicted and simulated emittance growth, e.g., for the CERN PS | 05.12.2006 | EM, FZ | high | PLANNED |
| repeat AD Experiment in Simulations (GR) | 26.09.2006 | GR | high | IN PROGRESS |
| simulate effect of SPS collimator on growth rate vs. chromaticity for different energies | 26.09.2006 | GR | high | IN PROGRESS |
| SPS e-cloud simulations at 26 and 60 GeV for a dipole field | 05.05.2006 | GR | high | IN PROGRESS |
| GR and FR will follow-up ideas on debunching transverse impedance measurements with GA, ES, and FZ | 10.03.2006 | GR, FR | medium | PLANNED |
| structured list of intensity limits for CERN and GSI | 03.02.2006 | FR et al | high | DONE for CERN, LUMI'06 (GA) and web site |
fundamental questions
| action | date | in charge | priority | status |
| derive general formula for longitudinal resistive-wall impedance | 19.05.2006 | EM, +student | medium | PLANNED |
| attempt to derive a general nonlinear theory including the inductive bypass | 18.03.2005 | EM | low | PLANNED, plan to recruit Ph.D. student |
| review Landau-damping mechanisms | 13.10.2004 | EM, FZ | very low | PENDING |
Completed RLC Actions
| action | date | in charge | priority | status |
| add 2003 minutes and presentations to the RLC web site | 17.03.2006 | FZ | medium | DONE, fall 2006 |
| scaling of the effective LHC collimator impedance as a function of the collimator gap, bunch length & bunch spacing | emails by FR, 27.04.2006 and 08.05.2006 | EM, FZ, GR | high | DONE by EM and FZ. EM presented results at LTC 6.12.2006 |
| contact Trevor for help with impedance calculations | 07.11.2006 | OB | high | DONE, 21.11.2006 |
| organize team meeting on impedance database plans | 07.11.2006 | WH | medium | DONE, 21.11.2006 |
| check definitions of transverse impedance with J. Tuckmantel and possibly B. Zotter | 03.03.2006 | FZ | high | DONE, email exchange with J. Tuckmantel, inconclusive |
| develop a lattice for crab cavity option | 03.03.2006 | RT, FZ | high | DONE, presented at LUMI'06 |
| perform e-cloud simulations for the two SPS working points. | 11.11.2005 | EB->FZ,GR,GF | high | PLANNED , task reassigned 03.02.2006, DONE by GF and EB in summer 2006 |
| compute longitudinal impedance for an IPM model | 17.05.2005 | AG | high | DONE, 10.03.2006 |
| provide WH and HB with information for activity presentations in general group meeting 28.09.2006 | 12.09.2006 | All | high | DONE, 28.09.2006 |
| contact Bruno Spataro and/or Derun Li for Y-Chamber MAFIA input files | 07.11.2006 | EM | high | DONE, 28.11.2006 |
| provide OB with information on US LARP | 12.09.2006 | All involved | high | DONE, 22.09.2006 meeting with Hermann Schmickler |
| Review of Stupakov paper | 07.11.2006 | EM | low | DONE, 21.11.2006 |
| TDI: Inform ABMB & Brennan about need of rf fingers; check gap with Ralph | 19.09.2006 | OB and EM | high | DONE, 26.09.2006 |
| send code questionanire to Tom Roberts for g4beamline | 19.09.2006 | FZ | high | DONE, 20.09.2006 |
| Clarify differences in Hereward & M-S dispersion relations? | 07.07.2006 | EM? | medium | DONE, 19.09.2006 |
| TDI follow up: gap requirements, operation mode, heating, no of units w/o ferrites & spares | 12.09.2006 | EM | high | DONE, 19.09.2006 |
| contact rf group for possibly higher-quality bunch profiles | 05.05.2006 | GR, FZ | high | DONE, APC 18.05.2006 |
| contact Stefano Redaelli to clarify number of TCTV | 17.03.2006 | EM, AG | highest | DONE, 07.04.2006 |
| short note on the TCDS impedance estimates that can be referenced to in the Functional Specifications | 07.04.2006 | AG | high | DONE, 05.05.2006 |
| include all contributions to the broad band impedance in the stability diagram both at injection and at top energy | 07.04.2006 | EM | high | DONE, 21.04.2006 |
| inform collimation team that a gap of 12 mm is needed for two devices and 30 mm in case of more than 2 devices |
17.03.2006 | FR | highest | DONE, 17.03.2006 |
| contact GA and/or Bruno Spataro to clarify whether high Q's of these modes include effect of a load |
10.03.2006 | GR | high | DONE 17.03.2006 |
| collect existing literature on resistive coatings by FC, check scaling and the damping required for half of nominal LHC intensity, and clarify logics for correct reply to IPM team. | 10.03.2006 | EM, AG | high | DONE 17.03.2006 |
| HFSS simulations for tertiary collimators | 18.11.2005 | AG | high | ALMOST DONE, 03.02.2006; DONE 17.03.2006 |
| develop theory for 2-beam resistive-wall wake field | 17.02.2006 | FZ | high | DONE 03.03.2006 |
| inform Warner Bruns about suspected bug in GdfidL | 17.02.2006 | AG | very high | DONE, 17.02.2006 |
| inform Manfred Mayer of TCTV changes suggested | 17.02.2006 | AG | very high | DONE, 17.02.2006 |
| produce plot comparing theoretical prediction with transverse collimator impedance inferred from FC&TK's measurement, taking into account driving and detuning wakes | 03.02.2006 | FZ | high | DONE by EM and FZ, 10.02.2006 |
| obtain access to FC for TDI wire measurement | 03.02.2006 | AG via LB (FR) | high | DONE, 10.02.2006 by AG (email) |
| send email to D. Macina on TOTEM Roman Pots | 03.02.2006 | FR | very high | DONE, 06.02.2006 |
| literature search for 2-beam wake fields | 18.11.2005 | EM, FZ | high | COMPLETED, 16.12.2005 |
| check exact timing of bunches at TCTV and TCLIs | 18.11.2005 | RA | high | DONE by SR and AG 13.01.2006 |
| tentative conclusion for PS kicker impedance limiting cases | 18.11.2005 | EM | high | DONE, PRESENTATION by EM 20.01.2006 |
| stability limit for Cu secondary collimators | 18.11.2005 | EM | medium | 1ST ESTIMATE DONE 01.12.2005, final 2nd ESTIMATE 03.02.2006 |
| check adequacy of conducting boundary conditions for HEADTAIL simulations | 18.11.2005 | GR | medium | PARTLY DONE 01.12.2005 COMPLETED 20.01.2006 |
| discussion of the SPS single-bunch electron-cloud instability and incoherent effects scaling with energy in reply to ES. | 11.11.2005 | FZ | high | COMPLETED, 18.11.2005 |
| clarify the offset at the first turn and the offset at which beam loss occurs for SPS fast vertical instability | 14.10.2005 | EM | medium | COMPLETED, 21.10.2005 |
| follow up optics with beta*=2 m with LOC team and experiment | 03.06.2005 | WH | medium | COMPLETED, 23.09.2005 |
| extract transverse impedance from bench measurement data | 08.07.2005 | FZ | high | COMPLETED, 15.07.2005 |
| compare and understand the different predictions of the Burov-Lebedev theory calculated by FZ and EM. | 13.05.2005 | EM, FZ | high | COMPLETED, 17.06.2005 (only question mark which remains is Piwinski theory, FZ - SOLVED 26.08.2005) |
| produce a plot of HT growth rates as a
function of chromaticity at injection energy for nominal current |
10.06.2005 | EM, FZ | highest | COMPLETED, 17.06.2005 (one further cross check will be done by FZ for coupled-bunch growth rates |
| analytical/numerical estimate of the slot impedance for TCDS & TCDQ | 10.06.2005 | AG, EM | high | COMPLETED, 17.06.2005 (no hardware change will be requested) |