Calibration summary Nov-Dec 09

R Apsimon

10 Nov 09

• Note, the power rail on the FONT5 board wasn’t working properly and so there is no good quality information to be had from this data, no point putting up the calibration plots

P1 P2 P3

Cal 1 2.0257e-3 1.6213e-3 2.2445e-3

Cal 2 2.1321e-3 1.7727e-3 2.3436e-3

19 Nov 09

• FONT5 board sent off to UK for repairs, so using the FONT4 boards.

• P3 has a broken strip and so the data for this was unusable and therefore not shown.

3 procs on 3 BPMs single-bunch

P1 3-bunch mode

P2 3-bunch mode

Summary

P1 P2

Single-bunch 2.4739e-3 2.3805e-3

3-bunch 2.2339e-3

2.2566e-3

2.2059e-3

2.3648e-3

2.3103e-3

2.3370e-3

03 Dec 09

• Strange nominal optics this week. Due to malfunction lattice file also not saved by control system.

• Running with 3 processors on 3 BPMs in 3-bunch mode for this shift.

P1

P2

P3

Summary

P1 P2 P3

3-bunch 2.7237e-3

2.7908e-3

2.9661e-3

2.7298e-3

2.6661e-3

2.6948e-3

3.6385e-3

3.6109e-3

3.3292e-3

11 Dec 09

• Using Machine LO, but it was jumping around a lot, causing the sampling to jump.

• Still trying to analyse the data from this set, but very difficult to remove the pulses sampled off-peak. How much time is worth devoting to ana

17 Dec 09

• FONT5, 4 processors on 3 BPMs. P2x and P2y for comparison. ZV6X for y-cal, ZH4X for x-cal.

• P2x channels were not sampling on peak and are on different ADC clocks, so the calibration constant is only approximate.

Y-calibration

P1 y calibration

P2 y calibration

P3 y calibration

Haven’t yet investigated why this constant is so low.

Analysis on P2x

• Assumptions:– Sum and Diff signals gaussian within ±2.8ns– Sigma ~ 2.8ns

• Method– Add point either side of peak. This value

approx. peak value within 1 sigma, maximum error ~ ±25%

Sum of points either side of peak

Gauss fit to sum signal

Estimation of peak position

• Using the assumptions stated earlier, can estimate how far the sample is off peak.– Won’t bore you with the maths…

• On diff peak, the line is very ratty at first, this is because the quadrature component makes the apparent position of the peak change, so method not reliable in this region.

Estimated peak position

Calibration constant

• Integrating across pulse, so calibration constant should tend to 0.0026 not 0.0022 as it does if sampling the peak.

• Taking into account the estimated peak positions and my peak value estimation, this constant will be multiplied by 1.128/1.262=0.894, which will give a “theoretical” calibration constant of 0.002324

P2x calibration

This calibration is in good agreement with the “theoretical” value

Enlarged diff for P2x, bunch1

Note the top 3 positions appear to have a peak about midway between the 2 samples and the lower 3 positions’ peaks are varying due to the quad component

Enlarged sum for P2x, bunch1

Note the sum pulses are much closer to being on peak and all the pulses appear to be the same shape, implying the same peak

Bench test results

• LO at 14dBm, input: 650Mhz sine wave at 0dBm, split 2 ways with 1dB attenuation on arm into input A, no attenuation on arm into input B. Also displaying results from previous bench test

Bench test results

7dBm LO

650MHz input

14dBm LO

650MHz input

14dBm LO

700MHz input

Proc 1 Diff out 26.6mV 29.9mV 44.3mV

Sum Q 5.38mV 5.94mV 7.98mV

Sum I 5.18mV 5.94mV 8.28mV

Proc 3 Diff out 23.9mV 26.96mV 38.3mV

Sum Q 5.38mV 6.08mV 8.34mV

Sum I 5.18mV 6.00mV 8.70mV