Calibration Performance
Use the links on the left to see detailed calibration performance plots (where avaliable).
Summary
Intra-Channel Calibration
The resolution of the intra-channel calibration has been estimated by measuring the period of the reference clock (which is present in channel 9), the resolution of the calibration is taken as the RMS of the distribution. It should be noted that in the below table no attempt has been made to decouple the spread due to actual changes in the clock period, or those that come from the measurement method used. As such, these numbers should be taken as upper bounds on the resolution of the calibrations.
| Calibration Name | Type | Resolution |
|---|---|---|
| kVoltageTime | None | 460 ps |
| kVT*RG* | Integral | 146 ps |
| kVT*JW* | Differenital | 81 ps |
Intra-SURF Calibration
No performance data as of yet (although see talks from Jiwoo and Andres, and probably others).
Inter-SURF Calibration
This has also been estimated using the clock channel data, and as such it is hard to draw firm conclusions. However, the fit method appears to perform marginally better with seemingly narrower SURF to SURF timing distributions that are more closely clustered around zero. Until this test is repeated using external data, all conclusions can only be preliminary. The following table comes from the analysing the 2nd positive transition of the clock waveform.
| Calibration Name | RMS of Mean | Mean of RMS |
|---|---|---|
| kVTFullJWPlusFastClockZero | 196 ps | 111 ps |
| kVTFullJWPlusClockZero | 107 ps | 100 ps |
The RMS of Mean column is intended as an estimator on systematic error (i.e this is an estimate of the fixed offset not taken out, or induced, by the calibration), the Mean of RMS is intended as an estimator of statistical error (i.e the event to event stability of the calibration).
Cable Length
No performance data as of yet, the most complicated calibration to check. One could imagine a mis-calibration of the cable lengths producing a systematic change in the reconstructed angle.
Copyright © 2006 Ryan Nichol, (last modified 07 Jun 2007)