Update on Drive Beam BPM

DevelopmentAlfonso Benot Morell, CERN BE-BI

CLIC Module Working Group Meeting, 24 April 2013

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

Stripline BPM prototype terminated in short-circuit (with SiC damper) installed in TBL (CLEX)• In the proximity of the last PETS• Influence of ~130 MW 12 GHz RF non-local signal?• Low-Frequency operating readout electronics (<50

MHz)• May need external 12 GHz notch-filtering solutions

A 50Ω-terminated stripline BPM prototype has been designed (with SiC damper)• Initial design improves 12 GHz filtering effect• SiC dampens HOMs but also HF components• Manufacturability issues• Electrode-Feedthrough transition• SiC Ring Thickness

CLIC Module Working Group, 24 April 2013

1- Status

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

Contents

CLIC Module Working Group Meeting, 24 April 2013

Intended use of 3rd null in frequency response as 12 GHz notch filter (>40 dB fall needed)

L_elec = 37.5 mm (nominal)

2-50Ω-Terminated Stripline BPM Prototype

CLIC Module Working Group, 24 April 2013

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

CLIC Module Working Group, 24 April 2013

2.1 – Initial Design

Parameter name Valuel_conus [mm] 2l_elec [mm] 36.3l_gap [mm] 5l_pin [mm] 8l_pipe [mm] 10l_sic [mm] 2.75

phi2 [°] 10r_blend [mm] 0.4r_conus [mm] 2.5r_elec [mm] 12.5r_out [mm] 13.54r_pin [mm] 0.73r_pipe [mm] 11.5

r_sphere [mm] 0.6

CLIC Module Working Group, 24 April 2013

2.1 – Initial Design

CLIC Module Working Group, 24 April 2013

2.1 – Initial Design

CLIC Module Working Group, 24 April 2013

2.1 – Initial Design Manufacturability issues

◦ Additional SiC ring +1.80mm 4.25mm total SiC thickness◦ Transition Electrode-Feedthrough Small spheres left on beam

side of pipe 3rd lobe degraded

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wide gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

Parameter name Valuel_conus [mm] 2l_elec [mm] 36.3l_gap [mm] 5l_pin [mm] 8l_pipe [mm] 10l_sic [mm] 2.75

phi2 [°] 10r_blend [mm] 0.4r_conus [mm] 2.5

r_elec [mm] 13.4r_out [mm] 14.6

r_pin [mm] 0.73r_pipe [mm] 11.5

r_sphere [mm] 0.6

CLIC Module Working Group, 24 April 2013

2.2 – Thick electrodes

CLIC Module Working Group, 24 April 2013

2.2 – Thick electrodes1.9 mm thickness

CLIC Module Working Group, 24 April 2013

2.2 – Thick electrodes1.5 mm thickness

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

1.5mm thick electrodes + 7mm gap

CLIC Module Working Group, 24 April 2013

2.3 – Wide Gap

Parameter name Value

l_conus [mm] 2

l_elec [mm] 10

l_gap [mm] 7l_pin [mm] 8

l_pipe [mm] 10

l_sic [mm] 2.75

phi2 [°] 10

r_blend [mm] 0.4

r_conus [mm] 2.5

r_elec [mm] 13

r_out [mm] 14.1r_pin [mm] 0.73

r_pipe [mm] 11.5

r_sphere [mm] 0.6

1.5mm thick electrodes + 7mm gap

CLIC Module Working Group, 24 April 2013

2.3 – Wide Gap

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

Latest proposal

CLIC Module Working Group, 24 April 2013

2.4 – Alternatives

Parameter name Value

l_conus [mm] 2

l_elec [mm] 10

l_gap [mm] 5.8l_pin [mm] 8

l_pipe [mm] 10

l_sic [mm] 2.75

phi2 [°] 10

r_blend [mm] 0.4

r_conus [mm] 2.5

r_elec [mm] 12.5

r_out [mm] 13.54

r_out_sic [mm] 14.2r_pin [mm] 0.76

r_pipe [mm] 11.5

Latest proposal

CLIC Module Working Group, 24 April 2013

2.4 – Alternatives

Change electrode shape• Circular end rectangular (blended edges)• Tapering

External 12 GHz filtering

CLIC Module Working Group, 24 April 2013

2.4 – Alternatives

1. Status2. 50Ω Terminated Stripline BPM

2.1 Initial Design2.2 Thick Electrodes2.3 Wider gap2.4 Alternatives

3. Conclusions

Contents

CLIC Module Working Group Meeting, 24 April 2013

Frequency response Extremely sensitive to SiC

Parameters to vary:• L_gap• L_sic• L_elec ?

Search for manufacturable (L_gap,L_sic) to have >40 dB fall after 3rd lobe (12 GHz)

Further simulation needed

CLIC Module Working Group, 24 April 2013

3 - Conclusions

Thank you

CLIC Module Working Group, 24 April 2013