L1Cal Pedestal Studies

1
L1Cal Pedestal Studies

• Sabine Lammers
• Philippe Laurens
• 26-Sep-2006

2
Test Conditions on 26-Sep-2006

• This data was collected starting around 1830,
  while the detector was closing. 
• The closing process normally takes 1 hour, but
  took closer to 4, and we think they started
  shortly after 6pm. 
• The conditions for these tests thus probably
  started closer to (C) with the iron in motion.  
• (A) CAL powered but not read out PDT A-Layer off
  (powered down) SMT off CFT on iron open
• (B) CAL powered but not read out PDT A-layer on
  SMT off CFT on iron open
• (C) CAL powered but not read out PDT A-layer on
  SMT on but not read out CFT on iron open
• (D) CAL powered but not read out PDT A-layer on
  SMT on but not read out CFT on iron closed

3
Iron Closing
Raw ADC oversampled data Average and Standard
Deviation of 4x159636 independent 1,000 point
histograms
Example HD_TT(9,19) Fairly quiet
4
Iron Closing
Raw ADC oversampled data Average and Standard
Deviation of the samples used for the 36 Live
Crossings
Example HD_TT(9,19) Fairly quiet
5
Iron Closing
Example HD_TT(9,22) High 132ns synchronous
noise Low Turn-wise synchronous noise
6
Iron Closing
Example HD_TT(9,22) High 132ns synchronous
noise Low Turn-wise synchronous noise
7
Iron Closing
Example HD_TT(9,9) High 132ns synchronous
noise High Turn-wise synchronous noise
8
Iron Closing
Example HD_TT(9,9) High 132ns synchronous
noise High Turn-wise synchronous noise
9
Iron Closing
Random Noise does not change noticably while Iron
is Closing
10
Iron Closing
Pedestal Fluctuation wrt. Live X (i.e. turn-wise
synchronous noise) increases while Iron is
Closing