LHC Crab Cavity Engineering Meeting

US/Central
Hermitage Room, Industrial Center Building, 2 East (FNAL)

Hermitage Room, Industrial Center Building, 2 East

FNAL

Batavia, IL
Erk Jensen (CERN), Rama Calaga (CERN), Tommy Peterson (FNAL), Vyacheslav Yakovlev (FNAL)
Description

Charge:

  1. Review fabrication challenges for the three compact cavities and the present test results

  2. Review present conceptual ideas of the two-cavity cryostat including the tuning mechanisms, Helium vessel, shielding, thermal and mechanical analysis, RF system, controls, alignment, instrumentation and integration. Its future adaptation towards the final LHC system should be addressed.

  3. Review the timeline for fabrication of the two cavity cryostat and respective systems for the SPS tests and the related prototyping effort.

Summary Report
Participants
  • Alessandro Ratti
  • Alick Macpherson
  • Alireza Nassiri
  • Allan Rowe
  • Binping Xiao
  • Bob Kephart
  • Chase Boulware
  • Dmitry Gorelov
  • Eric Montesinos
  • Erk Jensen
  • Giorgio Apollinari
  • Graeme Burt
  • Jean Delayen
  • John Skaritka
  • Krzysztof Brodzinski
  • Luís ALBERTY
  • Mathieu Therasse
  • ofelia capatina
  • Qiong Wu
  • Rama Calaga
  • Sergey Belomestnykh
  • Shrikant Pattalwar
  • Subashini De Silva
  • Terry Grimm
  • Thomas Jones
  • Tom Nicol
  • Tom Peterson
  • Vyacheslav Yakovlev
  • Zenghai Li
  • Thursday, December 13
    • 8:45 AM 10:30 AM
      Review Fabrication Techniques, present status & test results
      Convener: Thomas Nicol (Fermilab)
      • 8:50 AM
        Introduction 10m
        Brief welcome and an introduction to meeting and its objectives. Some logistical information will be provided.
        Speakers: BOB KEPHART (FERMILAB), Giorgio Apollinari (Fermi National Accelerator Laboratory (FNAL))
      • 9:00 AM
        UK 4Rod Prototype 20m
        A technical overview of UK 4rod cavity development and construction at 400 MHz toward a crab cavity for the LHC. Cavity design and present status including deflecting mode characteristics, HOM spectra, damping scheme, coupler configurations associated choices should be addressed. The cavity fabrication challenges, treatment and recent test results should be reviewed as appropriate.
        Speaker: Dr Graeme Burt (Cockcroft Institute)
        Slides
      • 9:20 AM
        ODU-SLAC RF Dipole Prototype 20m
        A technical overview of the ODU-SLAC cavity development and construction at 400 MHz toward a crab cavity for the LHC. Cavity design and present status including deflecting mode characteristics, HOM spectra, damping scheme, coupler configurations and associated choices should be addressed. The cavity fabrication, treatment and recent test results should be reviewed as appropriate.
        Speaker: De Silva Subashini (Old Dominion University)
        Slides
      • 9:40 AM
        BNL Quarter Wave Prototype 20m
        A technical overview of the BNL quarter wave cavity development and construction at 400 MHz toward a crab cavity for the LHC. Cavity design and present status including deflecting mode characteristics, HOM spectra, damping schemes, coupler configurations and associated choices should be addressed. The cavity fabrication, treatment and recent test results should be reviewed as appropriate.
        Speaker: Qiong Wu (Brookhaven National Lab)
        Slides
      • 10:00 AM
        Prototype Cavity Stress Analysis 20m
        Simulations of comparing the cavity integrity for the three designs up to a maximum pressure of 2 bar which maybe reached during the cool-down for cavity prototypes along with CERN recommendations for stiffening and appropriate modifications are presented.
        Speaker: Luís Alberty (CERN)
        Slides
      • 10:20 AM
        Discussion 10m
    • 10:30 AM 10:45 AM
      Coffee 15m
    • 10:45 AM 12:15 PM
      Cryostat Design I, Helium Vessel & Tuners
      Convener: Dr Alireza Nassiri (Argonne National Laboratory - DOE)
      • 10:45 AM
        General Specifications 20m
        General regulations applicable to the pressure equipment (Cavity, Helium vessel & Cryostat) both for SM18 RF tests and SPS beam tests will be reviewed. Based on the European directives, general specifications pertaining to the LHC crab cavities are outlined. Aspects of safety, material for different elements and properties are discussed to comply with the CERN infrastructure and regulations.
        Speaker: Ofelia Capatina (CERN)
        Slides
      • 11:05 AM
        Helium Vessel/Tuner, ODU-SLAC RF Dipole 20m
        Detailed design of the ODU-SLAC RF dipole Helium vessel and magnetic shielding conforming to the specifications of both pressure vessel code, tuning and magnetic shielding to stay within the specified limits should be outlined. The tuning mechanism for the cavity should be presented with mechanical simulations conforming to the static and dynamic tuning requirements along with its interface to the cryostat.
        Speaker: Jean Delayen (Old Dominion University)
        Slides
      • 11:25 AM
        Helium Vessel/Tuner, BNL Quarter Wave 20m
        Detailed design of the BNL quarter wave Helium vessel and magnetic shielding conforming to the specifications of both pressure vessel code, tuning and magnetic shielding to stay within the specified limits should be outlined. The tuning mechanism for the cavity should be presented with mechanical simulations conforming to the static and dynamic tuning requirements along with its interface to the cryostat.
        Speaker: Binping Xiao (BNL)
        Slides
      • 11:45 AM
        Helium Vessel/Tuner, UK 4Rod Cavity 20m
        Detailed design of the UK 4rod cavity Helium vessel and magnetic shielding conforming to the specifications of both pressure vessel code, tuning and magnetic shielding to stay within the specified limits should be outlined. The tuning mechanism for the cavity should be presented with mechanical simulations conforming to the static and dynamic tuning requirements along with its interface to the cryostat.
        Speaker: Tom Jones (STFC)
        Slides
      • 12:05 PM
        Discussion 10m
    • 12:15 PM 2:00 PM
      Lunch 1h 45m
    • 2:00 PM 3:45 PM
      Cryostat Design II, Couplers & Cryogenics
      Convener: Sergey Belomestnykh
      • 2:00 PM
        Power Coupler Interfaces & RF System 30m
        The power coupling schemes for the three cavities are reviewed for the nominal and maximum power flow and suitable common platform vacuum to air interface is proposed. The interfaces to the RF source and the cryostat is also presented with general layout of the powering system for the SPS tests and initial concepts for the final LHC system.
        Speaker: Eric Montesinos (CERN)
        Slides
      • 2:30 PM
        HOM Couplers & Damping 30m
        The designs of the HOM couplers to be used on the three cavities is reviewed along with their transmission properties. A common platform high pass filter for HOM damping is proposed with the aim of prototyping the coupler and filter stages for warm cavity tests to meet the impedance budget. HOM coupler layout and preliminary heat load estimates are given to compare the complexity of the integration into a cryostat.
        Speaker: Zenghai Li (SLAC)
        Slides
      • 3:00 PM
        Cryogenic Circuit & Heat Loads 30m
        2K operation of the SPS BA4 cryogenic system for a crab cavity test in horizontal configuration with two adjacent cavities in a single cryostat. Helium availability, pressure, cryo circuits, safety valves, protection, overall installation effort,cost, time line, maximum heat loads and the impact on the overall SPS/LHC during regular operation is described. Aspects of cryogenic testing in the SM18 test facility and a conceptual design of the final LHC system is outlined.
        Speaker: Krzysztof Brodzinski (CERN)
        Slides
      • 3:30 PM
        Cryostat II, Discussion 15m
    • 3:45 PM 4:00 PM
      Coffee 15m
    • 4:00 PM 5:50 PM
      Cryostat Design III, Cryostats Concepts & Ancilliary Equipment

      Guidelines to session on cryomodules.
      1. Final crab cavity system requirements Interfaces to the LHC accelerator system, cryogenic system, and tunnel infrastructure Thermal conditions, cavity temperature, intercept temperatures, heat loads Cavity arrangement, supporting structure and possibility for alignment, beam-beam spacing and allowance for two beams, how many cavities per cryostat? Constraints from vertical and horizontal crabbing schemes RF coupler and HOM/LOM configurations and constraints Tuner configurations and constraints Instrumentation requirements Cryostat, piping, and helium vessel safety, code compliance requirements

      1. Given the final system requirements above, what features are most important to test in the prototype? How may the prototype differ from the final design? Possible topics: Cavity support structure, same as final design? Arrangement of multiple cavities. Same total number of cavities? Provisions in the prototype for one beam only? Cryostat vacuum vessel differences RF couplers and HOM/LOM configuration and orientation through the cryostat Special instrumentation not in the final cryostat Cryogenic connections, interfaces to infrastructure may differ from final design.
      Conveners: Tommy Peterson (Fermilab), Vittorio Parma (CERN)
      • 4:00 PM
        SPS BA4 Boundary Conditions 30m
        The role of the CERN working group in place to discuss all aspects of infrastructure and technical coordination for crab cavity tests in the SPS and LHC. Its mandate to identify and resolve constraints and issues associated crab cavities in the SPS and develop the constraints and design requirements. Draft functional specifications for an installation of a two cavity cryostat in the SPS BA4 region and associated consequences for the present experimental program. Some issues related to planning is also described.
        Speaker: Alick Macpherson (CERN)
        Slides
      • 4:30 PM
        Cryostat Concept, BNL Quarter Wave 15m
        A proposal of the conceptual design of the cryostat for the BNL quarter deflecting cavity should be outlined with general considerations on mechanical, thermal and integration aspects. The concept should foresee a two cavity prototype cryomodule for the SPS tests which can later be adapted towards a final LHC system with their respective constraints.
        Speakers: John Skaritka (BNL), Sergey Belomestnykh (Brookhaven National Laboratory)
        Slides
      • 4:45 PM
        Cryostat Concept, UK 4Rod Cavity 15m
        A proposal of the conceptual design of a cryostat for the UK 4rod deflecting cavity should be outlined with general considerations on mechanical, thermal and integration aspects. The concept should foresee a two cavity prototype cryomodule for the SPS tests which can later be adapted towards a final LHC system with their respective constraints.
        Speaker: Mr Shrikant Pattalwar (CCLRC, Daresbury Laboratory)
        Slides
      • 5:00 PM
        Cryostat Concept, ODU-SLAC RF Dipole 15m
        A proposal of the conceptual design of the cryostat for the ODU-SLAC RF dipole deflecting cavity should be outlined with general considerations on mechanical, thermal and integration aspects. The concept should foresee a two cavity prototype cryomodule for the SPS tests which can later be adapted towards a final LHC system with their respective constraints.
        Speaker: Dmitry Gorelov (Niowave Inc.)
        Slides
      • 5:15 PM
        Cryostat III, Discussion 30m
    • 7:30 PM 9:30 PM
      Meeting Dinner 2h

      Venue to be announced shortly

  • Friday, December 14
    • 9:00 AM 10:20 AM
      Cavity Cryostat Testing & Integration in SM18
      Convener: Allan Rowe (FNAL)
      • 9:00 AM
        Cavity Treatment (BCP, Heat Treatment & HPR) 20m
        A present state of the art cavity treatment and its application to the crab cavity designs should be discussed.The CERN facilities for cavity chemistry, heat treatment and HPR systems should be reviewed. Future prospects to reach the improved performance and stability should be outlined.
        Speaker: Sergio Calatroni (CERN)
        Slides
      • 9:20 AM
        SM18 Vertical/Horizontal Test Setup 20m
        The SM18 vertical and horizontal test stands for RF testing of cavities is presented. RF power system setup and cryogenic availability for testing is reviewed. The present status and future plans for the overall SM18 SRF infrastructure including the clean rooms, assembly procedures and HPR treatments of high performance cavities is reviewed.
        Speaker: Mathieu Therasse
        Slides
      • 9:40 AM
        SPX Cryomodule Concept & Status 20m
        Speakers: John Mammosser (Jefferson Lab), Dr Robert Rimmer (Jefferson Lab)
        Slides
      • 10:00 AM
        Discussion: Cavity Testing & Assembly 20m
    • 10:20 AM 10:40 AM
      Coffee 20m
    • 10:40 AM 12:30 PM
      Discussion I: Fabrication, Schedule, SM18 Testing & Integration
      Convener: Dr Erk Jensen (CERN)
      • 10:40 AM
        Overall Planning & HiLumi Meeting Highlights 30m
        Outline of the crab cavity work package within the HL-LHC upgrade including thedistribution of R&D tasks, time line for R&D and construction, cost estimate over the duration of the project, and man power estimates.
        Speaker: Dr Erk Jensen (CERN)
        Slides
      • 11:10 AM
        Helium Vessel/Tuner Fabrication & Challenges 30m
        Fabrication of the different types of Helium vessels and tuner systems, their advantage and disadvantages should be reviewed. Challenges in the design choice and fabrication steps along with feasibility of a two cavity cryostat within the specified scheduled should be reviewed and mitigation should be discussed.
        Speaker: Ofelia Capatina (CERN)
        Slides
      • 11:40 AM
        Cryostat Fabrication & Challenges 30m
        Fabrication of the different types of cryostat and their advantage and disadvantages should be reviewed. Challenges in the design choice, fabrication steps, integration along with feasibility of a two cavity cryostat within the specified scheduled should be reviewed and mitigation should be discussed.
        Speaker: Tommy Peterson (Fermilab)
        Slides
      • 12:10 PM
        Wrap Up Discussions, Recommendation & Final Comments 20m