Shuichi Noguchi,SRF2007,10.7 1

New Tunersfor ILC Cavity Application

Shuichi NoguchiKEK

Shuichi Noguchi,SRF2007,10.7 2

OutlineBrief IntroductionNew Tuners for ILC ApplicationElliptical CavityPulsed OperationHigh GradientLorentz Detuning Compensation( Cavity Deformation by Maxwell Stress )

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Frequency TunerRF Accelerating Cavities usually have Tuners.They are used to tune the Cavity Resonance Frequency, in order to minimize the reflected RF power, usually.Tuning Accuracy << Resonant Band WidthThey must cover the Wide Range of the Fabrication Error.Feed-back can be used in CW operation.

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Possible Error Sources

Fast in TransientOffsetSlowSlow

Slow

Static

Speed

Small Micro-Phonics ( Vibration )

ComparableLorentz De-tuningComparableDe-tuning OffsetComparableBeam Loading ( if φ is not 0 )

ComparableDrift ( Temperature, Pressure )

Very LargeFabrication Error

Magnitude/ Bandwidth

Error Sources

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Tuning Principle : by Slater

Volume Change of ΔV Frequency Change of Δf

( )

( )∫

∫

Δ

Δ

−≈

−+=

V

V

VdHEWf

fW

VdHE

22

0

22

20

2

41

21

μεδ

με

ωω

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Normal Conducting SuperconductingStretch / Squeeze

β～１

Piston Tuners

3000N/mm

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New TunersSeveral Candidates for the ILC Cavity

RequirementStroke > 2mm, Axial Force > 6000N

It must not move the Beam Axis.Compact and Reliable

Fast Response Piezo

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1 2 3

Booster

Under TestUnder TestUnder TestUnder Test

TTFExperience

GearScrewWedgeSlide JackWorm GearWorm GearLarge ScrewBall-ScrewScrewLeverBladeBlade

ScrewCam & LeverSaclay-2ScrewLeverLeverSaclay-1Booster-3Booster-2Booster-1Tuner

Drive (Motor)Piezo

3000N/mmNeed

Force Boosters

Common Configuration of Tuners

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Drive Force

Fixed Point Acting Point

Lever

He Jacket

Bellows

Lever Arm

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Saclay -1 : Operation Principle

Design by M. Maurier and P. Leconte based of the MACSE tuner design

ΔLscrew

ΔLarmsΔLcavity

Second Lever

First Lever

Motor

Notch to absorb Span Change

Support RodScrew

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Saclay-1 on a TTF Cavity

Double Lever Tuner Stiffness~ 100 N/μm

Second LeverFirst LeverTwo Piezos

Motor & Gear Screw

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Saclay – 2 : Cam & Lever

Cam

Lever Arm

Drive Screw

Motor＆ Gear

Shaft

Shaft Support

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Saclay - 2 : Cam & Lever

EccentricShaft (Cam)

Shaft Support with Piezo

He JacketLever Arm

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Blade : Jack System

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Blade : Jack, Lever & Screw

LeverPiezo

Gear & Motor

Screw

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Blade Tuner 25 N/μm

Original DESY Revised INFN

Not Stiff, Fatigue of Blade, KS=13N/μm

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Ball Screw : Large Ball Screw

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Coaxial Ball Screw 500N/μmNeed Long Stroke Piezo, Fatigue of Blade

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Slide Jack : Roller Wedge & Screw

Caterpillar Roller Screw

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Slide Jack Tuner 290N/μm

Piezo Stack

Drive Shaft

Taper

Invar Rod

Caterpillar

Caterpillar

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Tesla-like STF Baseline Cavity Package

Pulse motor (outside)

Piezo elementReplaceable

Motor drive shaft

Titanium Jacket

2K He line Support base

Invar Rod

Slide Jack TunerNb/Ti Flange

Inside Magnetic Shield

Stiff Endplate

Fixed Coupler

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SummarySeveral Candidates for ILC ApplicationAfter Experimental Demonstration of Performances and Comparison from many Aspects, Decision will be done.Some of these Tuners can be used for other Application, with Simplified Design.