IPBPM issues (Limitation of resolution) Siwon Jang (KNU)

Contents The status of IPBPM resolution measurements –IPBPM calibration measurements with Y-port signals –IPBPM resolution measurements with Y-port signals –The limitation of resolution with Y-port signals The IPBPM measurements issues –Static signal and BPF –Ref. cavity BPM resonant frequency matching –IQ phase tuning –Honda electronics gain

Calibration run of IPBPM We performed calibration run under the 0dB to 30dB. –The used optics was 100 x 1000 beta optics, which optics has 1um level jitter for IPA, IPB, IPC. –The QDOFF was set to A of IP waist. –The used method was integration method from #54 to #80 sample numbers. –Also I’ and Q’ does not normalized by Ref_Y signal to compare with Honda san’s paper method. The Calibration factor was calculated by (All the signal was integrated), I’ = ( I*CosX + Q*SinX ) [counts], Q’ = ( Q*CosX - I*SinX ) [counts] Calibration factor = ( Δ I’ [coounts] )/( Δ Mover position [um]) All the I and Q signal were taken mean subtract calculation. 3

Calibration run of IPBPM

IPBPM A calibration The integrated calibration factor from 30dB to 0dB shows good ratio to around times for every 10B attenuation case. The fitting line was extrapolated from 30dB calibration fact or. 5

IPBPMs calibration The integrated calibration factor from 30dB to 0dB shows good ratio to around times for every 10B attenuation case. 6

Resolution calculation: 0dB We performed resolution run under the 0dB –The used optics was 100 x 1000 beta optics, which optics has 1um level jitter for IPA, IPB, IPC. –The QDOFF was set to A of IP waist. –The used method was integration method from #54 to #80 sample numbers. –Also I’ and Q’ does not normalized by Ref_Y signal to compare with Honda san’s paper method. The Calibration factor was calculated by (All the signal was integrated), I’ = ( I*CosX + Q*SinX ) [counts], Q’ = ( Q*CosX - I*SinX ) [counts] Calibration factor = ( Δ I’ [coounts] )/( Δ Mover position [um]) All the I and Q signal were taken mean subtract calculation. Predicted position was calculated as follow equation, –Predicted position of IPA-YI’ = a1*IPB-YI’+ a2*IPB-YQ’+a3*IPC-YI’+ a4*IPC-YQ’+ a5*Ref-Y –Residual of IPA-YI’ = Measured IPA-YI’ – Predicted IPA-YI’ 7

20dB calibration 1220 owl shift

0dB calibration 1220 owl shift

IPBPM resolution Study The calibration factor of IPA with 0dB was counts/um. The ADC counts was multiplied 2.5 times for 5V range. 10

IPBPM-A resolution 11 RMS of residual for IPA resolution calculation (RMS = counts) : RMS/(Calibration factor)= counts/( counts/um)= nm Geometrical factor x RMS/cal = nm Measured chage/norm charge x Geo X RMS/cal = nm

IPBPM-B resolution 12 RMS of residual for IPA resolution calculation (RMS = counts) : RMS/(Calibration factor)= counts/( counts/um)= nm Geometrical factor x RMS/cal = nm Measured chage/norm charge x Geo X RMS/cal = nm

IPBPM-C resolution 13 RMS of residual for IPC resolution calculation (RMS = counts) : RMS/(Calibration factor)= counts/( counts/um)= nm Geometrical factor x RMS/cal = nm Measured chage/norm charge x Geo X RMS/cal = nm

Beam orbit re-construction 14 The data set was taken under the 0dB attenuation. [mm]

The comparison with old IPBPM The High-Q IPBPM was achieved 8.72 nm with 0.6 x 1.6nC, which corresponds to 5.94nm with nominal beam charge. Also the measured residual counts was wi th full BPM output ports. If only used Y-port data then the residual counts changed to counts, which c orresponds to 27.37nm with 0.6 x 1.6nC. Also this value corresponds to 16.43nm w ith nominal beam charge. Therefore, the Low-Q IP-BPM also have a possibility that the resolution can be redu ced with full channel calculation. The current BPM resolution has limit around 20nm with Y-port so that we expect if we used full channel signals of IPBPM then we can get more good position resolution with IPBPM.

The IPBPM measurements issues Static signal and BPF Static signal with 0dBElimination of static signal By using BPF with 0dB Delay

The IPBPM measurements issues Ref. cavity BPM resonant frequency matching Time-dependence of θ IQ

The IPBPM measurements issues Ref. cavity BPM resonant frequency matching Tuner range: 3~10.5mm, Frequency range: 6.386GHz to 6.441GHz (f 0 : 6.426GHz) We will make table the resonant Frequency due to tuner depth.

The IPBPM measurements issues IQ phase tuning Figure by N. Blaskovic IPA(Y) Before the phase matching IQ angle has no time dependency After the phase matching IQ angle has time dependency

The IPBPM measurements issues Honda electronics gain

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