3/18/2003 Crosstalk study
Notes about time calibrator runs
Last updated: 3/18/2003 1:51 PM
The plan:
Take 6 measurements:
11578 – all channels enabled
11579 – only T0P0 enabled in T0P, all other masked out in the LEDI discriminator.
11580 – all channels enabled
11581 – only T0P4 enabled in T0P,
11582 – all channels enabled
11583 – only T0P9 enabled in T0P,
11584 – all channels enabled
Run logbook comments:
Run Log Date Run Type Mag Events (seq) Totals Comments Details
11584 03/17 14:26:50 FBTIME OFF 20743(1)
T0 special, all enabled.
11583 03/17 14:23:43 FBTIME OFF 20676(1)
T0 special. Enabled only T0P9 out of all TOP. Rates T0P=T0N=640, &=0
11582 03/17 14:20:42 FBTIME OFF 19647(1)
T0Special, all enabled
11581 03/17 14:17:49 FBTIME OFF 20137(1)
T0 Special. Enabled only T0P4 in T0P, rates T0p=T0N=680, T0N&T0P=0
11580 03/17 14:14:52 FBTIME OFF 19266(1)
T0 Special. All enabled.
11579 03/17 14:12:17 FBTIME OFF 19545(1)
T0 special. Only T0P0 enable in T0P. Rates T0N=T0P=660, T0N&T0P=0 Strange.
11578 03/17 14:08:13 FBTIME OFF 29629(1)
T0 special. All channels enabled. Note T0N counts 670 T0P = 1334. TON&TOP = 670
Notes about time calibrator runs
The T0P&TON starts counting when at least 2 channels in T0P are enabled. (I checked this again 3/18 at 12:59 and T0P&TON now fires from single T0P)
The TOP is counting 2 times faster than T0N, this is true only when all 10 channels are enabled.
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11578 All |
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11579 Only T0P0 |
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11580 All |
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11581 Only T0P4 |
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11583 Only T0P9 |
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11584 All |
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Summary
1. It is confirmed that there is a significant positive time shift in (all) channels when signal is alone relative to the case when all signals on are fired.
T0P0 – pair on the edge. Shift = +38*25 ps
T0P4 – pair in the middle. Shift = +43*25 ps
T0P9 – last active pair out of 17 in the cable. Shift = +30*25 ps
2. The dependence of the shift from the pair position on the cable is not obvious.
3. The time drift between measurements was small ~ 2*25 ps.