L1Cal Pedestal Studies: Tests from 21-Oct-2006

1
L1Cal Pedestal StudiesTests from 21-Oct-2006

• Sabine Lammers
• Philippe Laurens
• 31-Oct-2006

2
21-Oct-2006 Test Data

• A. Iron open, CFT SCL clocks disconnected, SMT
  off (12-Oct-2006)
• B. Iron closed, toroid off, all components on,
  nominal operating condition
• C. Relative to B Muon A-layer PDT off
• D. Relative to B Muon A and B PDT layers off
• E. Relative to B SMT off

3
Output Et data (i.e. showing Turn-wise noise)

• Reminder
• Output Et measurements display the Turn-wise
  component of synchronous noise.
• Output Et measurements are not sensitive to
  132ns synchronous noise if this noise component
  remains stable.
• Observations
• Turning off Muon Layer A B electronics did not
  significantly decrease the turn-wise noise
• Turning off SMT electronics did not eradicate but
  seemed to lower and modify the location of the
  turn-wise noise

4
Nominal
SMT off
µ AB off
µ A off
5
Nominal
Iron Closed SMT off
Iron Open SMT off
6
Pedestal landscape is sensitive

• Observations
• Turn-wise noise remains similar (i.e. the shape)
  but
• The L1Cal pedestals (i.e. the average) are
  shifted when the operating condition of other
  systems is changed.
• Anything that changes or shifts the large 132ns
  synchronous noise will change the L1Cal pedestals
  landscape

7
Nominal
SMT off
µ AB off
µ A off
8
Raw ADC data(i.e. showing 132ns noise)

• Observations for example trigger towers HD(9,9)
  and HD(9,12)
• Turning the Muon A-layer off drastically reduces
  the amount of 132ns synchronous noise but does
  not seem to reduce the Turn-wise noise.
• Turning off SMT does not reduce the 132ns
  synchronous noise and does not seem to reduce the
  Turn-wise noise for those towers.
• Four locations of Turn-wise noise

9
Nominal
SMT off
µ A off
HD(9,23)
µ AB off
10
Nominal
SMT off
µ A off
HD(9,23)
µ AB off
11
Nominal
SMT off
µ A off
HD(9,12)
µ AB off
12
Nominal
SMT off
µ A off
HD(9,12)
µ AB off
13
Raw ADC analysis over full HD coverage

• This is New Data
• Raw ADC profiling (4x159636 oversampled
  measurements) of HD Towers for full L1Cal
  coverage.
• Reminder
• Raw ADC measurements are sensitive to 132ns
  synchronous noise when looking at all 636
  samples.
• Raw ADC limited to the 36 LiveX reproduces the
  Output Et data (with factor of 2-3 from ADC-gtEt
  conversion), i.e. is sensitive to Turn-wise noise
• Observations
• Location of 132ns noise is very similar to
  location of Turn-wise noise
• but with effect being an order of magnitude
  greater.
• Seems to be multiple noise sources, and separate
  primary causes for 132ns noise vs Turn-wise
  noise, but affect the same geographic areas of
  BLS signal

14
Raw ADC (new info)
36 LiveX i.e. Turn-wise
All 636 i.e. 132ns noise
Output Et (for comparison)
15
Highest 132ns syncrhonous noise

• Observations
• Towers with worst 132ns noise
• HD(-7,23)
• HD(-7,25)
• HD(-7,26)
• HD(-7,28)

• HD(-8,9)
• HD(-8,24)
• HD(-8,26)

16
HD Towers with highest synchronous noise HD(-7,23)
17
HD Towers with highest synchronous noise HD(-7,28)
18
HD Towers with highest synchronous noise HD(-8,24)
19
New oddities

• Observations
• Some towers seem to have sample dependent noise
  variations.
• Those towers seem to be isolated cases
• Dont know what this means
• Maybe an artifact from aliasing of large
  underlying 132ns noise?
• Look at this tower(s) with a scope?

20
HD Tower with sample dependent noise
??? HD(-7,17)
21
Clipped
Huge Noise
????
????
????