Re: congrats to successful TPC surgery

[Brendan Kiburg <kiburg@npl.uiuc.edu>]

Hi Peter,
   It really isn't clear to us what changed.  The curve started falling 
just before the beam went off around noon and did not recover when it 
came back.  It seems that no individual magnet moved very far, but it 
does seem that there was a somewhat systematic drifting on a sizeable 
fraction of magnets right around 12:00 today.
   We also observed that the muPC current seems wrong, we played with 
the cable and it didn't change.  We also read out the HV with a DMM and 
it was ~2500, it wasn't an HV change that you observed around 01:00, 24 
hours ago. 
   We could potentially go through another round of trying to tinker 
with it tomorrow and maybe just reset the beamline (with the changes 
that I haven't yet added to the macro).   Strangely, though the 
extinction is worse, the effective rate seems to be higher.

Perhaps these myseteries are coupled.
Regards,
Brendan


Peter Kammel wrote:

>and also to yesterday's beam improvements.
>
>My only question. What happened to the extinction?
>
>Do we understand that?
>
>With my best wishes
>
>Peter
>
>  
>