SPS New Wire Scanner Mechanics Review

Ray VenessBE/BI

Contents

• Introduction– Wire scanners– Requirement and concept for the new wire

scanner• Project timeline and funding• Motivation for this meeting• What BI would like from this meeting

Limitations

Reproducibility much larger as required by specification

Beam size min LHC 130, PSB 2000 um

Flexible design of wire fork Deformation of fork are not

measured Angular position measurement

outside of vacuum system Lever arm play is not measured

Speed regulation circuit Analog feedback loop difficult to

optimize Secondary particle acquisition

system Requires accurate adjustment of

working range Saturation effect of PM

Dynamic of working range small < 200

Tail measurement limited by noise

High intensity beams cause an increase of background signal

Dynamic of working range reduced

Aging of bellows18.04.2013 Wire scanner design review; B.Dehning 4

Motor

&

Position

sensor

Proposal of PhD thesisJuan Herranz 28.09.2012

Optic FiberVacuum chamber

Motor Stator

Wire

Fork

Beam

Vacuum pipe

Optic Disc in vacuum

Resolver

BearingsShaft

Rotor in vacuum

Methodology - Conceptual Design

Slide Courtesy of J.Herranz Alvarez

6

From Schematic to Design

Optic FiberVacuum chamber

Motor Stator

Wire

ForkRF screen

Optic Disc in vacuum

Resolver

Bearings

Shaft

Rotor in vacuum

Magnetic lock

The Project

• Project timeline – Dec 2012: Production of a prototype for SPS installation

launched with MME– April 2013: External design review validates design– May 2014: Installation of the prototype tank in SPS sector 517– Jan 2015: Installation of the prototype instrument in the tank– EYETS 2016: Installation of a PS Booster prototype– LS2: Installation of 18 instruments + spares in PS, PSB, SPS– LS2-LS3: Installation of 4 or 8 instruments + spares in the LHC

• Funding– Fully funded by LIU for the injectors and HL-LHC for the LHC

18.04.2013 Wire scanner design review; B.Dehning 7

Motivations for the Meeting

• Smaller beam sizes and higher intensities will make this new design specification essential for transverse profile meaurement post-LS2, so it is a key instrument for the LIU project– Existing instruments are 30+ years old and suffer from obsolescence and reliability issues– Other projects and labs are already interested in this design

• We have a prototype that has been designed, built, installed in the SPS and has been operated in the lab, however…

• Manufacture cost was high, acceptable for a prototype but not for a series of 20-40 instruments– We need to address this both in design and production engineering

• Manufacture time was long and relied heavily on CERN-specific skills, (i.e. EB welding) at a time when CERN workshops were loaded i.e. during LS1)

• Some vacuum issues were found late during acceptance testing– We need to make all the qualification tests needed and agree early on materials, treatments (and

bakeout for the LHC)• The SPS prototype design we have will not fit in the PS Booster

– There are clear benefits from having one design, with a few different components across the whole accelerator complex

What BI would like from this meeting

• A list of all the things that we think we can improve from the prototype:– Design, standardisation, materials, manufacturing

technology, ease of manufacture, alignment– … and cost!

• Discussion on the best way forward:– Communication between BI, MME and VSC– In house manufacture vs. sub-contracting– Is this a large series?