Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Part III ILC BCD Cavity

Maximum Use of Potential Performance Maximum Use of each Cavity Performance Maximum Availability

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Problems of Cavityfor ILC Application

Large Scatter of Maximum Gradient Large Dynamic Lorentz Detuning Long MTBF for Critical Components > 20 years --- < 5 % ／ year

Maximum Use of Potential Performance Maximum Use of each Cavity Performance Maximum Availability

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Common Numbers are necessary Number of Spare Cryomodules < 30 How many modules can we replace in a schedul

ed shutdown ? MTBF / Life Time ? How many critical component in a cryomodule ? Number of cavities to be repaired in a year < ? How is the lowest gradient we have to operate ? Distribution of the Max. Gradient Where do we set the threshold gradient ?

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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ILC BCD Cavity Parameters　 ILC BCD Cavity I=10mA, 1.5msec. X 5Hz ACD

　 　 Idea Problem Comments 　Material Niobium Bulk Well Established 　 Nb/Cu Clad, Single Crystal

Frequency 1.3GHz 　 　 Lower Frequency

Operating Temperature 2 k 　 　 　Number of Cell 9 　 　 >9, Super Structure

Gradient 31.5 MV/m 　 Performance Scatter 35 MV/m

Duty 1.5 msec. X 5 Hz Pulse Operation Dynamic Lorentz Detuning 　Cell Shape Elliptical 　 　 Low loss

Iris Aperture 70 mm 　 　 Smaller Aperture

Wall Thickness 2.8 mm 　 Need Stiffener 　　 　 　 　 　　 　 　 　 　

Input Coupler Double Window Coaxial Tunable Coupling Complex Many Candidates

HOM Coupler 　 High Pass + λ/ ４ Filter Compact 　Jacket 　 　 Not Stiff 　Tuner 　 　 Not Stiff Many Candidates

Magnetic Shield Outside of Jacket High Temperature Treatment 　 Inside of Jacket

　 　 　 　 　Vacuum Seal Al Alloy Hexagon 　 　 　

　 　 　 　 　　 　 　 　 　

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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DESY

Cavity Support 　 System is weak.

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Scatter of Maximum Gradient

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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First Test Before Installation

After Installation

Gradient Distribution

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Lorentz ( Maxwell ) Detuning

S

22

kk0

kmode

k

KBA

aa

accacc

l

EldfdE

FFdld

ldfdfff

Ｋｊａｃｋｅｔ

Ｋ tuner

Ｋ cavityF FＦｚＦｒ

　 　 TESLA Blade

STF Slide Jack

STF Ball Screw

A Hz/(MeV/m)2 0.5 0.5 1.2

B N/(MeV/m)2 0.047 0.047 0.051

df/dl Hz/μm 320 320 370dF/dl N/μm 3 3 1.8KS N/μm 13 80 60

Kjacket N/μm 26 96 58Ktuner N/μm 26 500 1700

Δf (30MV/m) Hz 1490 620 1360Fine Tuning

Stroke μm 3.7 1 2.9

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Mechanical Oscillation Modes

Multi-cell Mode (I)f = 87 Hz

Multi-cell Mode (II)f = 169 Hz

Tuner Mode f = 294 Hz

Single-cell Modef = 3.91 kHz

９７２MH Cavity

Tuner

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Stiff Jacket Baseplate (Ti)

Thick Titanium Baseplate No Stiffener

2.8 t 3.5 t

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Dynamic Lorentz DetuningResults at TTF 　

Pkly < 10 % → 　 Detuning angle < 12 deg. , f < 46Hz

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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TTF Lever Arm Tuner

Top Heavy

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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TTF Blade Tuner

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Slide Jack Tuner

Piezo Stack

Drive Shaft

Taper

Invar Rod

Roller

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Tuner and Jacket

Input Coupler Port

Piezo Stack

Slide Jack

Drive ShaftTitanium Jacket

Support Base

Invar Rod

2K He Line

Motor OutsidePiezo Replacement OK

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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A prototype coaxial ball screw tuner

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Input Coupler

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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TTF-3 Coupler

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Input Coupler for Baseline Cavity

5K cooling here80K cooling here

Beam pipeWarm window

Door-knob conversion

Cold window

Vacuum port

TRISTAN Type Coaxial Disk Ceramic

80 K 5 K 2 KStatic Loss 5 W 1.1 W 0.05 WDynamic Loss 3 W 0.2 W 0.03 W

Qext = 2.0 x 106

Prf = 350 kW

An improved input coupler design for simplicity with no tuning mechanism.

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Components for High Power Test Stand

Input Couplers Doorknobs

Coupling Waveguides

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Coupler Opening

Piezo can be replaced

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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HOM Coupler

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Gradient Control

U(t)V(t)ωV(t)dtd

Qω)

QQj(1V(t)

dtd 2

oL

o

o

L2

2

)tan(exp)(exp)~~(~~ tT

jTtVVVV

FFdod

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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jt

Tj

TtQ

QRPV

FFog expcostanexpexp1

12 2

jQ

QRIjQ

QRPV obog expcos

11exp

12 2

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Input Power Error

Coupling Error

Tuning Error

Phase Error

Cavity Voltage Error & Gain Reduction

Beam Phase

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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Item Device Pros Cons CostPower Variable

DividerPower Efficient Can be equipped after

Necessary for other Cavities

Second Divider

Can be equipped after

Space, Not Power Efficient

Qin

Tunable Coupler

ComplicatedCan not be equipped afterwards

3-Stube Tuner

Can be equipped after Performance Measurement

3-Motors Most Expensive

Phase Shifter

Can be equipped after Performance Measurement

Hayama ILC Lecture, 2006.5.23, Shuichi Noguchi

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　 Rough Cost 　 　 　 　 　 　 　　 　 　 30% 50% 70% 100% 　 　　 　 　 　 　 　 　 　 　

Control Replace by Fix WG 　 　 Need U-Part

　 Replace by Tunable WG Manual 　 　

　 Replace by Tunable WG

Remote 　 　

　 　 　 　 　 　 　 　 　Power Add Second

Divider Fix 　 Need Space

　 　 Manual 　 　　 　 Remot

e 　 　　 Replace Divider Fix *** 　 　　 　 Manual *** 　 　　 　 Remot

e *** 　 　　 　 　 　 　 　 　 　 　

Coupling Add 3-Stub Tuner Fix 　 Need Space

　 　 Manual 　 All from the beginning

　 　 Remote 　 　

　 　 　 　 　 　 　 　 　　 Tunable Coupler Manual *** *** *** 　 　　 All from the

beginningRemot

e *** *** ***