Cavity tuning etc

CryogenicsCavity tuning

TunerInput couplers

6th October 2009 video meetingK.Nakanishi

Crab Cavity & Coaxial Coupler in Cryo-module

Support Rod

Jacket Type Main He vessel SUS316L

Jacket Type Sub He vessel

Coaxial Coupler (Nb)

Stub Support

Crab Cavity CellNotch Filter

Support PipeTuning Rod

RF Absorber

Extract TM010, TE111 ModeFrequency Tuning

Input Coupler

Bellows

KEKB review 2007K.Hosoyama

Main He Vessel

Sub He Vessel

Input Coupler

Stub Support

Coaxial Coupler

Beam

Cooling Water

Liq. He In

Gas He

Cooling He Gas & Cooling Water

RF Monitor Gas He

BellowsRF Absorber

RF Absorber

Cooling Water Cooling Water

Notch Filter

Flow Meter

Control Valve

Cooling Water

KEKB review 2007K.Hosoyama

Ice balls

Pretuningf 0

Expanded length

Pretuning

• The cavity must be expanded about 5mm.• Length of Support lodes should be adjusted.

Support lod

He vessel

Frequency Tuning by Main Tuner by A. Kabe

Main Tuner Position (mm) Main Tuner Position (mm)

Reso

nanc

e Fr

eque

ncy

Load

[kg]

Tuner

• In KEKB, the tuner stroke is set as 5mm (~100kHz).

• The tuner stroke is limited 10mm(200kHz) by bellows.

• The tuner speed that is limited by motor is about 1kHz/s

Tip of input couplers

prototype HER

It looks good. It’s not shiny.

LER

Some of purple stains were found.

Horizontal testing

Achieved Vkick Applied RF Power

HER 1.8MV 120 kW

LER 1.93MV 55kW

QL

Input power Observation HER(Jun/2006)

HER(Nov/2006)

LER(Dec/2006)

Prototype(Feb/2006)

RF power (1) 10kW Band width 1.59x105 1.66x1051.86x105

1.3x106

RF power (2) 20kW Decay time 1.66x105 1.34x1052.07x105

Simulation (HFSS v9.2) 1.66x105 1.0x106

Q0 values at design kick voltage were higher than 1x109.