shuichi noguchihayama ilc lecture, 2006.5.231 part iii ilc bcd cavity maximum use of potential...

Shuichi Noguchi Hayama ILC Lecture, 2006.5.23 1

Part III ILC BCD Cavity

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


Common Ｉｍａｇｅ is necessary

How many Spare Cryomodules ? How many modules can we replace in a

scheduled 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 ?


DESY


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 Nb Endplate + Ti Cylinder High Temperature Treatment Not Stiff Ti Thick Endplate

Tuner 　　 Stiffness, Reliability Many Candidates

Magnetic Shield Outside of Jacket High Temperature Treatment 　 Inside of Jacket

　　　　　

Vacuum Seal Al Alloy Hexagon 　　　

　　　　　

　　　　　


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


Scatter of Maximum Gradient


First Test Before Installation

After Installation

Gradient Distribution


Lorentz ( Maxwell ) Detuning

S

22

kk0

kmode

k

K

BA

a

a

accacc

l

E

ld

fdE

FFd

ld

ld

fdf

ff

Ｋｊａｃ

ｋｅｔ

Ｋ tuner

Ｋ cavityF FＦｚ

Ｆｒ

　　 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 320 320 370

dF/dl N/μm 3 3 1.8

KS N/μm 13 80 60

Kjacket N/μm 26 96 58

Ktuner N/μm 26 500 1700

Δf (30MV/m) Hz 1490 620 1360

Fine Tuning Stroke

μm 3.7 1 2.9


Mechanical Oscillation Modes

Multi-cell Mode (I)f = 87 Hz 1/9 Mode

Multi-cell Mode (II)f = 169 Hz 2/9 Mode

Tuner Mode f = 294 Hz

Single-cell Modef = 3.91 kHz

９７２MH Cavity

Tuner


Dynamic Lorentz DetuningResults at TTF 　

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


Stiff Jacket Baseplate (Ti)

Thick Titanium Baseplate No Stiffener

2.8 t 3.5 t


TTF Lever Arm Tuner

Top Heavy


TTF Blade Tuner


A prototype coaxial ball screw tuner


Slide Jack Tuner

Piezo Stack

Drive Shaft

Taper

Invar Rod

Roller


Tuner and Jacket

Input Coupler Port

Piezo Stack

Slide Jack

Drive Shaft

Titanium Jacket

Support Base

Invar Rod

2K He Line

Motor OutsidePiezo Replacement OK


Input Coupler

Double Window to prevent Catastrophe due to Window B

reak To close the cavity in the clean room Tuneability ?


TTF-3 Coupler


Input Coupler for Baseline Cavity

5K cooling here80K cooling here

Beam pipe

Warm 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.


Components for High Power Test Stand

Input Couplers Doorknobs

Coupling Waveguides


Coupler Opening

Piezo can be replaced


HOM Coupler


Gradient Control

U(t)V(t)ωV(t)dt

d

Q

ω)

Q

Qj(1V(t)

dt

d 2o

L

o

o

L2

2

)tan

(exp)(exp)~~

(~~

tT

jT

tVVVV

FFdod

0

0

0

2tan,2

LL

F QQ

T


jtT

jT

tQ

Q

RIV

FFbb expcos

tanexpexp1

1

10

jQQ

RIjQ

Q

RPV obogCW expcos

1

1exp

12 2

jt

Tj

T

tQ

Q

RPV

FFogg expcos

tanexpexp1

12 2

t

VC

Vb

Vg

Vf

VCW


Coupling Dependence of Vacc

10.0

15.0

20.0

25.0

30.0

35.0

Vc

[MV

]

Time

Vf Vcw

800900

10001200

1500

2000

2800320040004800

sec.449

.sec490

kW313

deg.0,,

4000

2667

mA10I

MV30

8

Numbers Reference

0

b

910X

e

F

g

b

C

o

T

T

P

V

Q


10.0

15.0

20.0

25.0

30.0

35.0

Vc

[MV

]

Time

Vf Vcw

0.5

0.6

0.7

0.8

0.9

Pg

0.951.01.051.10

10.0

15.0

20.0

25.0

30.0

35.0

Vc

[MV

]

Time

Vf Vcw

-70o

-65o

-60o

-55o

-50o

-45o

-40o

-35o-30o

-15o

0o

Detuning Angle


Input Power Error

Coupling Error

Tuning Error

Phase Error

Cavity Voltage Error & Gain Reduction

Beam Phase


Item Device Pros Cons Cost

Power Variable Divider

Power Efficient

Can be equipped after

Necessary for other Cavities

Second Divider

Can be equipped after

Space, Not Power Efficient

Qin

Tunable Coupler

Complicated

Can 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


　 Rough Cost 　　　　　　　

　　　 30% 50% 70% 100% 　　

　　　　　　　　　

Control

Replace by Fix WG 　　 Need U-Part

　 Replace by Tunable WG

Manual 　　

　 Replace by Tunable WG

Remote

　　

　　　　　　　　　

PowerAdd Second

Divider Fix 　 Need Space

　　 Manual 　　

　　 Remote

　　

　 Replace Divider Fix *** 　　

　　 Manual *** 　　

　　 Remote

*** 　　

　　　　　　　　　

Coupling Add 3-Stub Tuner Fix 　 Need Space

　　 Manual 　 All from the beginning

　　 Remote

　　

　　　　　　　　　

　 Tunable Coupler Manual *** *** *** 　　

　 All from the beginning

Remote

*** *** *** 　　

shuichi noguchihayama ilc lecture, 2006.5.231 part iii ilc bcd cavity maximum use of potential...

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