● Offer the reliable system to the Asian 　　 regional facility STF.

● Improve TTF design and demonstrate in the beam line 　 for RDR / TDR.

● Establish industrial design and make the precise cost estimation in close 　　 cooperation with industries.

Purpose of STF Baseline Cavity Development

Baseline Cavity Unit

Input Coupler Port

Piezo Stack

Slide Jack

Drive Shaft

Titanium Jacket

Support Base

Invar Rod

2K He Line

Motor OutsidePiezo Replacement OK

DESY

Cavity Support　 System is weak.

Stiff Jacket Baseplate (Ti)

Thick Titanium Baseplate No Stiffener

2.8 t 3.5 t

Thick Beam Pipe

Magnetic Shield

ＳＴＦ　Ｂａｓｅｌｉｎｅ　Ｃａｖｉｔｙ

Three STF-Baseline Cavities

The #4 Cavity will be delivered in the end of April.The vertical tests for 4 cavities will be carried out till the end of July.

Results of 1st Vertical Test (4. high field)

108

109

1010

1011

0 5 10 15 20 25

#1 Baseline Cavity ; 1'st Vertical Test

Qo 1.8K

Qo 4.2KQo

Eacc [MV/m]

1.8 ~ 2.0 K

4.2 K

Eacc, max = 19.1 MV/m

Qo = 4.7 x 109, Po = 82 W

Eacc, max = 7.8 MV/m

Qo = 4.7 x 108, Po = 47 W0.0001

0.001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25

#1 Baseline Cavity ; 1'st Vertical Test

x-ray [mSv/H]

x-ra

ys

[mSv

/H]

Eacc [MV/m]

X-rays Radiation Level

Eacc,max = 19.1 MV/m, Limited by Field Emission

The 2nd vertical test will be carried out after additional surface removal by EP.

Ｉｎｐｕｔ　Ｃｏｕｐｌｅｒ　ｆｏｒ　Ｂａｓｅｌｉｎｅ　Ｃａｖｉｔｙ

Improved input coupler design for simplicity & reduced cost (no tuning)

5K cooling here80K cooling here

Beam pipe

Warm window

Door-knob conversion

Cold window

Vacuum port

TRISTAN Type Coaxial Disk Ceramic

Static Loss 5 WDynamic Loss 3 W

Static Loss 1.1 WDynamic Loss 0.2 W

Qext = 2.0 x 106

Prf = 350 kW

Components for High Power Test Stand

Input Couplers Doorknobs

Coupling Waveguides

Ｔｕｎｅｒ　ａｎｄ　Ｊａｃｋｅｔ

Guide slider

Pulse motor (outside)

Piezo element

Slide Jack

Motor drive shaft(G10)

Titanium Jacket

2K He line

Support base

Invar Rod

Slide Jack Tuner

Piezo Stack

Drive Shaft

Taper

Invar Rod

Roller

Input Coupler

Warm WindowVacuum Port

Cold Window

80K

5K

Beam Pipe

Monitor Port

Low loss 0.2W to 5KHigher Static loss 1.2W to 5KNo Tuning