Assuming we fix the camac or trigger file issues in the D-tunnel, we still
have time this shift to finish a forward set up and prepare for the last
set-up R4-R7. Tomorrow the hall will be open and we will need all the time
until 7.45 am.
some (general) comments to chi's email:
> Also, it is hard to determine CC efficiency without a pre dertermined cut
> to select electrons. Simply require TOF ADC top + bottum < 5000 wil raise the
> calculated CC efficiency. For instance for box0 from 61% to 68%, and for
> box1, due to the increased presence of protons, it is from 50% to 70%.
> Maybe using e-p coincident trigger would be better on this matter.
It is electrons and not protons that fire the cerenkov!! Also, there are
no elastic protons more forward than TOF #6. I am confused: the cut <5000
is on the TDC (right ??) and it actually selects those events for which the
paddle TDC is a self-timed peak. For those events, presumably, a particle
went through a paddle scint after hitting the start counter, so they come
from the target.
But maybe you are ahead of me, I never used ADC cuts. Also, with low
statistics, what is the statistical significance of these results ?
> The Run plan ask the next run to start RC0. So I stopped run 2365 even
> though there is not enough statistics. At about 6:40, Cerenkov HV are
> raised by 10%. Run 2366 started with this setting.
The run plan asks for about 1000-2000 events in each paddle with some
sensible flexibility: if you have problem with a counter, and do
not/cannot know how to solve it quickly, we can't wait for eternity.
If you have already 900 events, but its a good time to change configuration,
then change configuration as the next shift may not know how to.
Now we know that for the forward 4 a few hrs are ok (1/2 shift) and for
TOF's 4-7 at least a shift. Which I thinks fits nicely with the factor 3
reduction in cross section we discussed.
> Again, it is hard to determine the LC1 efficiency without a clear tag of
> electron. It is hard to say if the new HV is better and I am running out
> of time.
>
> Chi
>
>
>
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