Hi, Chris!
I could change the voltages on all those tubes, but like John said, we
might mess up the timing... from your initial plot I thought only RTOF3
was bad enough to require intervention...
On the other hand, if gains are going down, maybe putting them back
by adding about 30 volts would not create that much of a timing shift...
just let me know if you think it should be done...
Adrian
On Sun, 7 Nov 2004, Chris Crawford wrote:
> hi adrian and john,
> i was also a little concerned about ltb5 also (and ltb9?). first from
> scalers, second from the yield plot. (left tof 4 is higher -> left tof 5 is
> lower) i expect a discontinuity between tofs 3,4 but not 4,5. finally, the
> eff plot still has problems, but you can see the same discontinuity in the
> magenta curve between TOF's l4 and l5. it might not be a big problem, but if
> we could add cerenkov's of opposite sector into the singles 'trig==7'
> trigger, then we could have a constant monitor of all of the TOF
> efficiencies.
> --chris
>
> ltt ltb ltc rtt rtb rtc
>
> 0 3337, 3736, 2866, 5237, 3567, 3357
> 1 4118, 3046, 2813, 3107, 3213, 2448
> 2 2849, 2541, 2193, 3035, 2618, 2257
> 3 2307, 2444, 1793, 1188, 1786, 1107
> 4 2805, 3123, 2022, 3209, 2314, 1980
> 5 2469, 564, 561, 1767, 1369, 1137 <<<<<
> 6 1391, 2132, 1199, 1366, 2081, 1166
> 7 1885, 1479, 1099, 1509, 1267, 972 8 1391, 1800, 1039, 1671,
> 732, 695 9 1514, 369, 367, 1042, 980, 681
> 10 1607, 1636, 974, 663, 975, 548 11 2875, 3621, 1904, 1909,
> 3069, 1248
> 12 1878, 2594, 1232, 987, 2706, 854 13 1825, 1447, 867, 2141,
> 2002, 1045
> 14 2426, 1721, 665, 1436, 2684, 1056
> 15 2192, 2790, 1210, 2305, 563, 530
>
> John Calarco wrote:
>
>> Need to look at TDC offset for RTOF3 now. Adding 50V should have caused
>> the transit time in the PMTs to be reduced. By how nuch? This is a
>> change of V of dV/V ~ 50/2500 = 1/50. Transit times are ~ 30 ns. So
>> were talking 0.6 ns ... rounds off to 1 ns.
>>
>>
>>
>> On Sat, 6 Nov 2004, Electronic Log Book wrote:
>>
>>
>>> Operator: adrian
>>>
>>> Runs 12373-12382 taken. Crunching...
>>> Run 12377 is shorter (CODA crashed - rebooted ROCs remotely).
>>>
>>> RTOF3 shown in Chris' recent efficiency picture seemed to have a problem.
>>> I tracked it down, the scalers for the bottom tube were consistently
>>> lower. Other tubes seemed lower too, but an ADC study of the recent
>>> hydrogen runs showed only RTOF3 bottom to be going down continuosly.
>>> Added an extra 50 volts on that tube during run 13282 (and Aaron rebooted
>>> HVGUI right after that run, so the changes should have taken effect).
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>
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