Alfonso Benot Morell, CERN BE-BI CLIC Module Working Group Meeting, 24 April 2013.

Update on Drive Beam BPM

Development

Alfonso 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


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



Contents


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




3. Conclusions

Contents



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


2.1 – Initial Design


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


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

3. Conclusions

Contents


Parameter name Value

l_conus [mm] 2

l_elec [mm] 36.3

l_gap [mm] 5

l_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] 13.4

r_out [mm] 14.6r_pin [mm] 0.73

r_pipe [mm] 11.5

r_sphere [mm] 0.6


2.2 – Thick electrodes


2.2 – Thick electrodes1.9 mm thickness


2.2 – Thick electrodes1.5 mm thickness



3. Conclusions

Contents


1.5mm thick electrodes + 7mm gap


2.3 – Wide Gap


l_conus [mm] 2

l_elec [mm] 10

l_gap [mm] 7

l_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] 14.1

r_pin [mm] 0.73

r_pipe [mm] 11.5

r_sphere [mm] 0.6

1.5mm thick electrodes + 7mm gap


2.3 – Wide Gap



3. Conclusions

Contents


Latest proposal


2.4 – Alternatives


l_conus [mm] 2

l_elec [mm] 10

l_gap [mm] 5.8

l_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] 14.2

r_pin [mm] 0.76r_pipe [mm] 11.5

Latest proposal



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

External 12 GHz filtering





3. Conclusions

Contents


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


3 - Conclusions

Thank you


Alfonso Benot Morell, CERN BE-BI CLIC Module Working Group Meeting, 24 April 2013.

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Transcript of Alfonso Benot Morell, CERN BE-BI CLIC Module Working Group Meeting, 24 April 2013.