US LHC Accelerator Research Program

FY07 Task Sheet; rev 1

**Task Name:** Study of a Rotatable Metal Collimator for LHC **Date:** 1
July 2006

**Responsible Person(s)** (overall lead, lead at other labs)**:**

Thomas W. Markiewicz, SLAC (lead)

**Budget** (specified for each lab)**:**

SLAC \$920k

**Project Status as of date of submission:**

The major deliverable of FY05, a [draft of conceptual design
report](http://www-project.slac.stanford.edu/ilc/larp/RC1 conceptual design report Rev1.pdf)
(CDR) and the [file of associated
figures](http://www-project.slac.stanford.edu/ilc/larp/RC1 CDR figures.pdf)
for a collimator consisting of two 13.6cm diameter by 95cm long copper
cylinders which could rotate to a fresh position if damaged is can be
found at:

-   CDR:
    http://www-project.slac.stanford.edu/ilc/larp/RC1%20conceptual%20design%20report%20Rev1.pdf

-   Figures:
    http://www-project.slac.stanford.edu/ilc/larp/RC1%20CDR%20figures.pdf

**The FY06 "hard" deliverables were:**

-   To have a technical review of the design by a small committee of
    external experts

-   To finalize and release the prototype CDR document

-   To construct a first mechanical prototype of the collimator. This
    prototype, labeled "RC1" was to have tested the thermal and
    mechanical properties of the design. This work was planned to be
    done in two phases:

    -   A single jaw will be supported as specified in the CDR and an
        external electric line source of heat used to test the cooling
        system and the deflection of the jaw under heat load.

    -   The full mechanical assembly of two jaws contained within a
        vacuum vessel whose dimensions are consistent with the CERN
        Phase I adjustment system will be made. Tests of mechanical
        precision and gap setting accuracy as a function of rotation
        angle will be made.

-   To produce a written performance report RC1

Additionally, we planned to

-   Continue to explore, refine and improve the estimates of collimation
    system efficiency, energy deposition and engineering performance.

-   Acquire the engineering details and hardware necessary to convert
    RC1 into a fully beam-testable prototype collimator (RC2) in FY07.

-   Prepare samples of copper and Glidcop to be sent to the BNL
    irradiation facility (BLIP) for irradiation in the 2006 run.

**FY06 (as of this date) summary:**

**Technical Design Review** of RC1 prototype held 15 December 2005. The
reviewers were Louis Bertolini (LLNL), Alex Makarov (FNAL), and William
Turner (LBNL). In addition to the SLAC RC project staff, Ralph Assmann
of CERN and several non-involved SLAC engineers attended.

-   The charge to the committee, attendees and talks given are available
    at:<http://www-project.slac.stanford.edu/ilc/ilcdocs_interface/meetings2/editor/detail_v1.asp?meeting_id=40>

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-   Review report available at:

> <http://www-project.slac.stanford.edu/ilc/larp/ReviewersReportFINAL.pdf>

-   Main findings

    -   Engineering staff should be increased

    -   Do not begin prototype construction until following details have
        been more fully specified

        -   Flexible support

        -   Central Stop

        -   Rotation drive

    -   Investigate performance of a copper clad stainless steel jaw
        configuration

-   In response to these recommendations, we have:

-   Stopped all thermal analysis and begun the design of the parts
    mentioned. This work is continuing.

-   Analyzed the bi-metallic cylinder suggested. It's performance was
    found to be inferior to the baseline copper (or GLIDCOP) material in
    the CDR.

-   Searched for and hired a full time mechanical engineer and full time
    designer to join the existing effort. These positions began 1 April
    2006.

**Adjustments to the FY2006 Work Plan and Budget**:

Manpower issues and the serialization of the design work recommended by
the review committee resulted in a \~ six month slippage of the
schedule. As a result we returned \$430k of the FY06 budget to LARP
management and will rebudget FY07 to account for this delay.

**FY 06 Q3 Accomplishments:**

The additional manpower effort has resulted in:

-   An improved jaw design. It is hoped that the factor of 4-5
    improvement in deformation under heat load will eliminate the need
    for the flexible jaw supports and central stop.

-   An improved scheme for routing cooling coils and substantially
    reducing the torque required to rotate the jaws.

-   Copper and Glidcop samples machined to the proper shapes have been
    sent to BNL, assembled in the target holder and have been undergoing
    irradiation since the BLIP run began on May 4, 2006.

-   The first test brazes of a 15cm long jaw sample have been completed
    and cut open for analysis. Improvements to the process have been
    specified and a procedure for construction of a full length jaw
    outlined.

-   Heater controller for thermal tests ordered and DAQ components
    specified

-   Clean work area acquired for collimator testing: already equipped
    with adequate filtering and ventilation.

**Remaining FY06 Milestones**

-   Braze a 95cm long jaw according to the latest design

-   Finish equipping of test area with power, water, lifting devices and
    DAQ.

-   Completing the single jaw thermal deformation and cooling tests

-   Issue the final RC1 design report, including the jaw support,
    stopper and actuator mechanisms

**FY07 Work Plan and Hard Deliverables**

-   Fabricate two full length jaws and mount in a CERN compliant vacuum
    vessel

-   Acquire a CERN LHC Phase I collimator jaw adjustment mechanism from
    the CERN supplier (AREVA, France), mate it to the vacuum vessel and
    test mechanical alignments and positioning

-   Issue a performance report

**Other FY07 Activities**

-   Continued modeling and understanding of the interplay of energy
    deposition, collimation aperture, collimation system efficiency,
    effective collimator performance under heat-induced deformation.

-   Development of plans for RC2, the fully functional prototype that
    will be beam tested at LHC.

-   Further elucidation of calculations, and beam tests to understand
    the nature and extent of the area of jaw affected in the
    asynchronous beam abort accident case.

-   Hiring of a full time fixed term staff member or postdoc at SLAC to
    assist in these activities.

**Outyear activities and schedule**

CERN has recently announced a \~ six month delay in the LHC schedule.
This means that 1 January 2008 ship deadline of RC2 to CERN can slip
accordingly. The schedule will be adjusted targeting the beginning of
FY09 as the delivery date of RC2 to CERN.

**FY07 Manpower Summary:**

  ---------------- ----------------- ---------------- -------------------
  ME               SLAC              1.25             FTE

  Postdoc          SLAC              1.00             FTE

  Physicist        SLAC              0.25             FTE

  Designer         SLAC              1.00             FTE

                                                      
  ---------------- ----------------- ---------------- -------------------

**Statement of expected follow-on work in subsequent years** (include
"ultimate" goal and time scale for this sub-program, as well as plans
for specific work and rough budget need for next 2 years)**:**

The ultimate goal of this sub-program is a successful design for low
impedance, high efficiency LHC secondary collimators. The design will be
validated with a sufficient but small (1-3) number of prototypes and
beam tests. The design specifications and the prototypes are the primary
deliverables. The time scale is set by the desirability of testing the
prototypes with LHC beam in 2008/09. Based on the design study,
prototype performance and overall experience with the Phase I
collimation system in actual LHC running conditions, CERN will decide
whether or not to proceed with the rotating collimator design. If a
decision is made to proceed, this sub-project will provide an
engineering drawing package to CERN and will support the effort to
commission the collimators once they are manufactured and installed by
CERN.

  --------- -------------------------------------------------------------
  FY 2004   Introduction to project

  FY 2005   Calculations leading to the conceptual design of the
            rotatable collimator

  FY 2006   RC1 CDR, development of brazing procedures, set up of
            collimator test lab and single jaw thermal deformation and
            cooling tests

  FY 2007   Construction and thermal-mechanical tests of RC1

  FY 2008   Design, construction and mechanical tests of RC2

  FY 2009   Transfer of RC2 to CERN and Beam Tests of RC2; Final drawing
            package for CERN

  FY 2010   Await production & installation by CERN

  FY 2011   Commissioning support
  --------- -------------------------------------------------------------

**Glossary:**

RC: Rotatable Collimator

RC1: Prototype with horizontal jaws, made of non-exotic UHV compatible
materials

RC2: Beam-test capable prototype with exotic materials

**Outyear budget estimates**:

  --------------------- ------------ ------------ ------------ -----------
  FY                    Labor        M&S          Shop         Grand Total

  2004                               11000                     11000

  2005                  170000       20000                     190000

  2006                  170000       50000        130000       350000

  2007                  500000       255000       165000       920000

  2008                  520000       190000       325000       1035000

  2009                  520000       53000        27000        600000

  2010                  200000       21000                     221000

  2011                  300000       64000                     364000

  Grand Total           2380000      664000       647000       3691000
  --------------------- ------------ ------------ ------------ -----------