Hi Maurik,
Below is some information, addressing each point. Hope it helps. We are
close to requiring the new TDC calibrations as input to other programs to obtain
other constants.
Cheers, Elton.
>
> Hello TOF folks,
>
>
> I am looking at the data for the TDC calibrations: runs 3550 and 5546.
> It's not quite clear to me what is going on in that data, so it is a
> little difficult to write a program to interpret it.
>
> I observe:
>
> 1) The first few hundred events don't have any TDC values in them.
> (Is that because the delta-t isn't long enough for the stop to come
> after the start ?)
reply: The start time always comes before the stop. However, there is an enable
time on the TDC and there is a period during which no valid data is returned.
During at least part of this period, the TDC will return a time of zero. That is,
data will not be sparcified, but there is no valid information. (Do you see this?)
>
> 2) After that the data exhibits a pattern in the channels:
> Slot 17: 0 1 4 8 12 16 20 24 28 32 36 40 41 44 etc.
> Slot 16: 0 4 8 12 16 20 24 28 32 36 40 44 etc.
>
> Notice the channels 1 and 41 appearing for Slot 17.
> Was this a mis-wiring ?
> Should my code warn the user and keep going ? Ignore those channels ?
reply: You are correct, channels 1 and 41 should not fire. If all correct channels
fire, it probably was not a miswiring. Probably, the discriminator mask(s) were
not inhibiting the pulse during that time. I suggest your code warn the user and
continue, perhaps indicating the frequency of firing. This could be an indicator
of the problem. While we should attempt to correct for this situation, this is
probably a benign problem, as it should not affect the resulting constants.
>
> 3) What is the pulse pattern ?
> I observe that each channel jumps in value by about 40 every 50 events.
> Am I correct in that you are pulsing 50 times, and then increase
> the delta-t by 2 ns ?
> How can I know ahead of time ?
reply: The pattern is determined by a file (currently in
~clasrun/auger/pulser.dat). Current settings are: 50 events/step/pattern, 200
steps, 4 patterns; steps every 2 ns; pattern every fourth channel.
>
> Thank you much for any reply,
>
> Maurik
>
>
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