LHC Collimation Working Group
(former  LHC Beam Cleaning Study Group)


List of pending actions from previous meetings

 

 

104th meeting of August 24th, 2009

Priority
Task
Responsible
Status
  Procedure for the SPS-LSS5 change layout request for the installation of the BPM-equipped collimator prototype. A. Bertarelli, R. Assmann Ongoing
  Provide energy deposition inputs for Phase II collimators to MME Luisella Lari Ongoing
  RBAC and MCS deployed on all the collimators in the tunnel. S. Redaelli, A. Masi Ongoing
  RBAC: roles and people for injection and dump collimators. R. Assmann, B. Goddard, S. Redaelli Ongoing

103rd meeting of April 27th, 2009

Priority
Task
Responsible
Status
 

Inputs expected from TOTEM before the beam operation:
(1) hardware parameters for the mechanical references
(2) handling critical calibration data for LVDT sensors TOTEM Summer
(3) hardware commissioning in the tunnel and feedback to OP

TOTEM team Pending
  Follow-up open issues for software implementation, as found in first controls integration tests. S. Redaelli, M.Dutour, S. Ravat Ongoing
 

Agreement on Roman pot names for the communication between TOTEM control room and CCC during operation.
See the operational database web page at this link.

TOTEM / OP Done
  Change of definition of “beam energy for physics” for the cross-calibration runs of Roman pots/collimator postioins. MPP Ongoing

99th meeting of March 2nd, 2009

Priority
Task
Responsible
Status
  FLUKA simulations of reference case for losses without cryo-collimators
Results presented at the collimation review.
FLUKA team Done
  Comprative studies for different materials of cryo-collimator
Results presented at the collimation review.
FLUKA team Done
  Detailed calculation and implementation of BLM collimator thresholds G. Bellodi, FLUKA team Done
  Ion requests for temperature sensor locations in IR3/IR7
Follow-up after the meeting: no additional requests for ion in the warm insertion.
J. Jowett, G. Bellodi Done

98th meeting of February 16th, 2009

Priority
Task
Responsible
Status
  Is it possible to compensate for the BLM cable length in order to have correct measurements for short int. time (instead than modifying the bump thresholds)? BLM team Pending

97th meeting of December 17th, 2008

Priority
Task
Responsible
Status
  Feasibility of bunch-by-bunch BLM gating for the LHC monitors of the transfer line collimators BLM team Pending
  Review settings of collimator BLM thresholds impemented for the 2008 operation BLM + collimation teams Pending
  Schottky pick-up to measure off-bucket beam properties? F. Caspers Pending

96th meeting of June 16th, 2008

Priority
Task
Responsible
Status
  Optimize on-line analysis required for TL collimator alignment Coll & Inj teams Pending
  Follow-up SPS MD planning for collimator tests S. Redaelli Ongoing
  Detailed calculation and implementation of BLM collimator thresholds BLM team Ongoing
  Collimator dump thresholds for ion operation J. Jowett Pending

94th meeting of February 18th, 2008

Priority
Task
Responsible
Status
  Submit a request for collimator MD's at the SPS (as discussed in the meeting)
See summary in the slides of S.Readelli and overall planning discussed at the APC.
R. Assmann Done
  Determine case studies for fast BLM data transmission to be tested in the 2008 SPS MD's M. Jonker Pending
  Upgreda old CSS collimator FESA class to the new OP system of the FESA gateways. M. Jonker Done
 

Provide to the BLM team the damage limits in proton losses per second for the various collimator types.
Table distributed by R. Assmann.

R. Assmann Done

 

93rd meeting of February 4th, 2008

Priority
Task
Responsible
Status
 

Provide AT-VAC a list of location for additional temperature measurements in IR3 and IR7.
See presentation by M. Brugger on vacuum pipe heating.

Follow-up on Collimation meeting of March 2nd, 2009: Proposal by AT-VAC: Excel file, PDF of IR3, PDF of IR7.

Coll. team + FLUKA + VAC Done
 

Provide to the FLUKA team the expected vacuum pressure and residual gas distribution in IR7.
Follow-up: M. Jimenez provided the following estimates:
- Gas composition: Hydrogen will be the main component.
- Static pressure of the order of 2-5 10e10 mbar
- Dynamic pressure: due to outgassing, it is expected to increase the pressure by a factor 10 for a deltaT of 50 deg. Desorption from impacting protons and electromagnetic showers has not been estimated in detail yet.
- See latest paper by A. Rossi at the LHC background workshop.

AT-VAC Done
  Procurement/set-up of third collimator prototype for impedance measurements.
The third prototype has been procured and is available for tests. However, it must be used for an unexpected endurance test of the mechanics (discusses at the CPS meeting of 19/02/2008). The prototype readiness for impedance measurements is POSTPONED accordingly (a delay of a few weeks is expected).
O. Aberle Done
 

Perform additional impedance measurement of
(1) Final samples of collimator Carbon materials
(2) Tungsten collimators

R. Assmann (procurement)
ABP impedance team
Ongoing

Definition of energy deposition studies for collimator Phase I

ABP + FLUKA teams

Ongoing

92nd meeting of January 21st, 2008

Priority

Task

Responsible

Status

  Implementation of energy limits for collimator gaps A. Masi Done
  Configuration of collimator inputs to the BIC's
Table with BIC connections: PDF (include also collimators not installed for 2008 run).
A. Masi Done
  Planning for collimator HW commissionig (per sector)
First planning that takes into account the constraints from HW commissioning was presented at the CPS meeting of 19/02/2008; Further updates will be announced here.
Followed up in the CPS meeting of 19/02/2008 Done
  Specification document for automatic beam-based procedures (input for AB/CO development) R. Assmann, M. Jonker Pending
  Calibration and interlocking issues for the fifth collimator axis (transverse tank movement) ATB-LPE Pending
  Propose temperature dump levels for the various colliator types
Update, Oct. 2008:
Proposal given in April 2008 to E. Blanco and fully implemented into the controls of the 2008 system (~400 temperture sensors)! Values for the first year of operation:
Jaw measurement:
Warning: ≥ 45 ºC
Interlock: ≥ 50 ºC
Measurement of cooling water temperature:
Warning: ≥ 30 ºC
Interlock: ≥ 35 ºC
RA+SR Done
  Collimator damage level during impacts of ion beams
JJ: awaiting DPA Implementation in FLUKA
J. Jowett, R. Bruce Pending
  Finalize the collimator MTF steps for the hardware commissioning T. Weiler Done

91st meeting of December 13th, 2007

Priority

Task

Responsible

Status

  Provide details of collimator FESA classes to E. Carlier
Update, summer 2008:
Description of the FESA interface for movable devices described in the EDMS note number 934341 by S. Redaelli). This defines the interface for setting and measurement properties, including the MCS thresholds, as well as the machine states.
Collimator control team Done
 

Prepare a TCDQ class with the same set/get properties at the collimator class
Update, Oct. 2008:
Interface for get and set properties (including threshold limits) implemented and successfully tested in preparation to the beam operation. Follow-up of the implementation for the 2009 operation is ongoing.

TCDQ controls team Done
  Follow-up TCDQ protection aspects and detailed implementation R. Assmann, R. Schmidt, B. Goddard Ongoing

90th meeting of December 10th, 2007

Priority

Task

Responsible

Status

  Feasibility of upgrading the collimator prototype in the SPS to the final LHC hardware for beam tests in 2008.
The SPS prototype cannot be upgraded for the 2008 run. The prototype will be left into the machine with the present hardware and will be kept operational for the 2008 run.
R. Assmann Done
  Procurement of collimator FESA servers R. Assmann, M. Jonker Done
  Final design of collimator FESA class M. Jonker, ATB-LPE, OP Done
  Follow-up of pending COCOST actions (details here) M. Jonker Ongoing

Updated action list for energy deposition studies (summer 2007)

Priority

Task

Responsible

Status

  Energy deposition in cold magnets from direct beam losses and gas scattering FLUKA team To be reported
  Passive absorber: performance with skew halo FLUKA team, input from ABP Done
  Design of absorbers with movable aperture FLUKA team To be reported
  Intervention scenarios, dose to personel for passive absorber repair
[FLUKA inputs are ready]
SC-RP Ongoing
  Performance of one-sided system FLUKA team, input from ABP Ongoing
  System performance with various commissioning scenarios (larger gaps) FLUKA team, input from ABP Ongoing
  Implementation of simulation errors: flatness, tilt errors, ... C. Bracco -> FLUKA team Ongoing
  IR3 FLUKA model, comparison with IPHE results FLUKA team, input from ABP Ongoing
  TCT damage level and corresponding BLM thresholds (1 nominal bunch) FLUKA team Pending
  TCLI protection performance Y. Kadi Ongoing
  Updated BLM response matrix for commissionign scenarios (Final BLM layout) FLUKA team, input from ABP Pending
       
  Related topics: Physics development: DPA implementation G. Smirnov, A. Ferrari To be reported
  Related topics: Physics development: ion scattering G. Smirnov, A. Ferrari To be reported

89th meeting of July 12th, 2007

Priority

Task

Responsible

Status

  Perform measurements of collimator low-frequency impedance F. Roncarolo, B. Salvant Ongoing
  Material procurement and control test stand availability for impedance measurements R. Assmann, M. Jonker Done
  Finalize the layout of the passive absorbers. Do we need additional protection? Do we want to ask for a change of the vacuum layout? R. Assmann, FLUKA team Done
  Investigate repair scenarios for the passive absorbers and corresponding radiation doses Coll. Design team + SC-RP Ongoing
  Dust production in the Tungsten material of the passive absorbers Collimation WG Pending
  Passive absorbers: energy deposition and dose studies for new operational scenarios: (1) larger collimator gaps; (2) reduced collimator system FLUKA + SC-RP team (inputs from ABP coll. team) Pending

88th meeting of July 4th, 2007

Priority

Task

Responsible

Status

  Implementation of crystal scattering routing in tracking tools V. Previtali Done

86th meeting of May 7th, 2007

Priority

Task

Responsible

Status

  Scraper design: provide assumptions/inputs for design R. Assmann, S. Redaelli Pending

85th meeting of April 23rd, 2007

Priority

Task

Responsible

Status

  TCDQ halo load: normalization of impacting particles L. Sarchiapone, T. Weiler Done
  Follow-up of 2007 SPS MD preparation S. Redaelli Done

79th meeting of November 27th, 2006

Priority

Task

Responsible

Status

  BLM thresholds for ions
The baseline is to use the same thresholds used for protons.
Ion collimation team Done
  BLM thresholds for collimator damage (TCT in particular) Fluka team + TS team Pending
  Proton losses in W/m for comparison with ion loss maps T. Weiler Done

74th meeting of July 17th, 2006

Priority

Task

Responsible

Status

  Temperature margins using as inputs realistic proton loss distributions ABP team -> D. Bocian Done

70th meeting of May 22nd, 2006

Priority

Task

Responsible

Status

  Understand different loss locations for B1 and B2 G. Robert-Demolaize Pending
  IR7 Fluka studies for B2 Fluka team Pending
  Include active absorbers (TCLA's) in the ion loss studies Ion team Ongoing
  Ion cleaning and loss maps with different TCP and TCS settings Ion team Pending
  Locations of additional BLM for ions in IR3 Ion team Done
(Note)

69th meeting of May 8th, 2006

Priority

Task

Responsible

Status

  Effect of orbit and beta-beat on the ion losses downstream of IR7 Ion team Ongoing
  Impact on the BI budget of additional BLM proposed for protons and ions BLM team Done
  Why off-momentum protons touch first a TCTH instead than the TCP of IR3? Ion team Done
  TCDQ halo load with single-sided collimation system L. Sarchiapone, T. Weiler Done
  TCDQ halo load with missing secondary collimators L. Sarchiapone, C. Bracco Done

68th meeting of March 20th - LHC ion collimation studies, 2006

Priority

Task

Responsible

Status

  BLM location in the dispersion suppressor of IR7 Ion + ABP + BLM teams Done
  Take into account crossing and separation bumps LHC ion team Ongoing
  Check the losses in the middle of the quadrupoles and not only at the magnet end LHC ion team Pending
  Setup ion collimation with SixTrack? LHC ion team + ABP team Pending
  Accident scenarios with ion beams LHC ion team + FLUKA team Pending
  Are TCT's required at IP2 for the early ion scheme? LHC ion team Done
  Updated simulations setup: (1) Increase particle diffusion speed every tracked turn instead than every 100 turns; (2) separate load contributions from different halo types (horizontal, vertical and skew); (3) Include TCLA's at IR3 and IR7 LHC ion team Pending
  Improve the efficiency by reducing the length of the primary collimators? LHC ion team Pending

67th meeting of March 20th - Plan for future FLUKA activities, 2006

Priority

Task

Responsible

Status

  Energy deposition studies with skew halo ABP team Done
  Cross-check FLUKA and IPHE simulations (model IR3 with FLUKA and IR7 with MARS) FLUKA and IPHE teams Pending
  Energy deposition at IR7 at injection energy FLUKA team Done
  Write-up documentation of the work carried out in the last months FLUKA team (Mario) Done
  Deposited energy in BLM's and cross-talk. FLUKA and BLM teams Done
  Thermo-mechanical calculations of failure scenarios at 7 TeV with 60cm long TCP's A. Bertarelli Done
  Energy balance FLUKA team Done
  Deposited energy for various commissioning scenarios ABP and FLUKA teams Ongoing
  Direct proton losses versus deposited energy in the cold magnets of IR7 ABP and FLUKA teams Pending
  FLUKA model of IR7 for beam 2 FLUKA team Pending
  Phase II studies - effect of different materials for the TCS FLUKA team Pending
  Halo loads on the TCDQ and downstream elements ABP and FLUKA teams Done
  Halo loads on the TDI and downstream elements ABP and FLUKA teams Pending
  Failure scenarios at injection ABP and FLUKA teams Pending
  Energy deposition studies for SPS and TT40 tests with beam ABP and FLUKA teams Done
  Crystal studies - deposited energy by channeled halo particles ABP and FLUKA teams Pending
  Define BLM thresholds for damage and deformation limits of the collimators (notably, for the ones in Tungsten) FLUKA team Pending

67th meeting of March 20th - Additional items, 2006

Priority

Task

Responsible

Status

  Implications of final IR7 layout on the bake-out system R. Assmann -> AT-VAC Done
  Difference between IR7 and IR3 (the latter requires less absorbers) IPHE team Pending
  Effect of deposited energy on the performance of various IR7 equipment Equipment owners Done
  Cooling required for passive absorbers TS-MME Done
  Report on tolerance for Ozone production at IR7 O. Aberle Pending

 

Old action list from 2005

Date

Task

Responsible

Completed

10.10.05 Cross check geometry of MBW's for the IR3 simulations of deposited energy R. Assmann -> J.B. Jeanneret and IPHE team Done
  Follow-up of simulation of radiation doses at the MBW's of IR7:
(1) Move passive absorbers in contact with the MBW coil
(2) Scaling law for radiation doses versus absorber length
(3) Try different material (W layer in critical regions?)
(4) "Movable" passive absorbers, like the TCLA?
FLUKA team Done
  Review simulation results of Ozone production at IR7. A. Presland Solved after the  meeting
  Investigate the production rate versus air speed. A. Presland Done
  What is the tolerable Ozone density for IR7? O. Aberle Done
  Check drawings of vacuum interconnects R. Assmann, O. Aberle + B. Dehning for BLM's Done
  Provide deposited energy at the BLM locations FLUKA team Done
  Larger statistics on beam loss maps for failure scenarios of secondary collimators becoming a primary collimator ABP collimation team Done
  Setup tracking and beam loss simulations for beam 2 ABP/LOC section -> ABP collimation team Done
  Force on the coils of the MBW magnets during field ramping. Effect on the epoxy spacer. S. Ramberger Done
       
19.09.05 Compare code developed at the Kurchatov institute with ANSYS for the case with no electromagnetic effects. A.Ryazanov's team Pending
  Convert the presented results in SKM unit system A.Ryazanov's team Pending
  Setup simulation with a real collimator geometry A.Ryazanov's team Pending
  Investigate the feasibility of a target beam test in 2006 to validate the simulation code by A.Ryazanov's team J. Lettry, R. Assmann, A. Bertarelli Done
       
27.06.05 Follow-up/proposal for a feedback test with collimators during the 2006 tests with beam at the SPS R. Assmann,
J. Wenninger
Pending
  Finalize the calculations of quench limit for the various LHC superconducting magnets R. Assmann,
L. Rossi
Pending
  Cross-check of energy deposition simulations for proton and ion studies V. Vlachoudis, J. Jowett, R. Bruce Ongoing
  Cross-check crossing and separation schemes in the simulations of ion losses H. Braun Pending
  Estimate the contribution of various halo load for ion simulations H. Braun Pending
  Review formulae for temperature dependence of specific heat A. Presland, Fluka team Done
  Energy deposition studies for asynchronous damp at 7 TeV with misfired bunches impacting on a secondary collimator A. Presland, input from ABP team Done
  Check if the deposited energy in the flanges is acceptable in the case of accident case scenario at 7 TeV A. Presland with C. Rathjen Done
       
13.06.05 Energy deposition studies with 60 cm long primary collimators at IR7 Fluka team, inputs from ABP team Done
  Accident scenario with 60 cm long primary collimators at IR7 Fluka team +
A. Bertarelli
Done
  Effect of TCP angle on cleaning performance and beam loss ABP team Pending
  Provide maps of deposited energy at the BLMs Fluka team Done
  Follow-up the feasibility of reducing the aperture at the passive absorbers of IR7 Fluka team +
C. Rathjen
Done
  Deposited energy in the coil of the dogleg dipoles of IR7, at the location where the coil is close to the vacuum pipe Fluka team Done
  Energy balance: how much goes into the beam pipe Fluka team Pending
       
 

Check the old list of pending items!