From: Brown, RM (Bob) - PPD [bob.brown@stfc.ac.uk]
Sent: 23 November 2007 18:43
To: Kennedy, Bruce
Cc: Cockerill, David; Sproston, Martin
Subject: FW: Rate effect - standard rate ddata

Attachments: Run_29810_raw_standardRate.doc

Bruce, thanks for the plots.

 

I note several features.

 

There are frequent spikes (fast large deviations from the mean).  Is the source understood?  I note that the effect also occurs in the pedestal run, does this mean that it is probably not a VPT effect?

 

There is a clear time dependence in the response of many of the tubes.  Most notably a rapid fall at the start of the run.  Presumably this is even after the first N(?)00 events have been discarded?

 

However, there are also longer term drifts in a couple of cases.  Is this understood?

 

How do these runs fit in with the other runs.  Is the slow run before or after?  What is the time interval between runs?

 

Bob.

 


From: Kennedy, BW (Bruce)
Sent: 23 November 2007 15:34
To: Brown, RM (Bob) - PPD
Subject: Rate effect - standard rate ddata

 

Bob,

 

Here are the standard-rate plots corresponding to the reduced-rate version you already have.  The vertical stripes which you see in the plots are a PAW artefact, not a feature of the data.

 

Bruce

 

 

--
============================================
Bruce Kennedy
Particle Physics Department, Rutherford Appleton Laboratory
Phone: (0)1235 445075          Email: B.W.Kennedy@rl.ac.uk