SPL tuning bench: status and results

Kai/Waqas

Setup

• Resonance frequency S11/S21 Measurement

• Field Flatness Bead Pull

Displacement measurements

1 2 3 4 5Strain Gages Input Port Pick-up

Bead

  Name Pieces

 1-MX840A QuantumX: DAQ module

1

1-WI/10MM-T Mini displacemnt transduc. WI/10mm,probe

4

Sensitivity Analysis

x – under straino - released

• Elastic limits vary from cell to cell due to pre-treatments and increase which each cycle plastic deformation range reduces (at the moment f < 30 kHz for all cells)

Elastic limits

Bead Size• Trade-off between sensitivity and linear

phase error• S21 one measurements for different bead

sizes and a network analyser that gets sick

step Bead size [mm] Lin. phase error*1 7.95 8.68%2 5.72 0.04%3 6.87 5.31%4 6.2 2.90%

*Linear phase error based on a fit with arctan function and compared with linear function

Tuning Procedure• Initial state of the Cavity

• Field flatness of 22 %• Resonance Frequency: 703.106 MHz

1

Bead pull measurement Frequency Correction

• Tuning to 703.2MHz decided due to limited deformation

Tuning Procedure

1

Tuning ProcedureInitial Cell 4 compressed

Cell 1 compressed Cell 2/4 pulled

Summary

• Tuning procedure elaborated and tested• heat treatment of the Cu Cavity (reset elastic

limits)• Further tuning of the test cavity afterwards• End cells should be tuned at the end• Upgrade of tuning bench yes/no?• Maximum frequency shift per cell +-170 kHz