Modifications of AFE boards

1
Modifications of AFE boards

• Removing of unused channels from readout
• green modifications, added resistor to unused
  channels this is how we started but we decided
  to abandon
• blue modifications, removed capacitor from unused
  channels
• Modifications for 53 MHz readout
• red modifications

2
Green ModificationsIncreased Spread Of Pedestals

• Run 182282, lights off, 4-Oct-03
• Run 180808, 1-September-03, last before Shutdown

3
Green ModificationsIncreased Spread Of Pedestals

• Run 182282, lights off, 4-Oct-03
• Run 180808, 1-September-03, last before Shutdown

4
Green ModificationsIncreased Spread Of Pedestals

• Run 182282, lights off, 4-Oct-03
• Run 180808, 1-September-03, last before Shutdown

5
Green ModificationsIncreased Spread Of Pedestals

• Run 182282, lights off, 4-Oct-03
• Run 180808, 1-September-03, last before Shutdown

6
Green ModificationsIncreased Spread Of Pedestals

• Reason was found for this
• Green modifications cause unused channels to fire
  discriminators continuously
• Paul Rubinov re-programmed 2 boards so that
  unused channels discriminators show up in data
  for first 4 MCMs. Board 7A4 is a board with green
  modifications, B0 is a board with blue
  modifications.
• Marvin warned us that chips firing continuously
  can have shorter lifetime.
• We decided to abandon green modifications.

7
Blue Modifications, board 8A2Increased RMS Of
Pedestals

• Run 182174 3-Oct-03, crate 0x50
• Run 182044 1-Oct-03 for boards 9A, crate 0x50
• Run 180808 1-Sep-03, last before Shutdown

8
Blue Modifications, board 9A3Increased RMS Of
Pedestals

• Run 182174 3-Oct-03
• Run 182044 1-Oct-03 for boards 9A
• Run 180808 1-Sep-03, last before Shutdown

9
Blue Modifications, board 8A0Unchanged RMS Of
Pedestals

• Run 182174 3-Oct-03, crate 0x50
• Run 182044 1-Oct-03 for boards 9A, crate 0x50
• Run 180808 1-Sep-03, last before Shutdown

10
Blue Modifications, board 8B7Improved RMS Of
Pedestals

• Run 182174 3-Oct-03, crate 0x50
• Run 182044 1-Oct-03 for boards 9A, crate 0x50
• Run 180808 1-Sep-03, last before Shutdown

11
Blue (Red) Modifications, crate 0x50Increased
RMS Of Pedestals

• Run 182174 3-Oct-03, crate 0x50
• Run 182044 1-Oct-03 for boards 9A, crate 0x50
• Run 180808 1-Sep-03, last before Shutdown
• 40 of boards have increased RMS (17-1)/41
• RMS of blue board RMS of unmodified board

12
Unmodified Boards in crate 0x51 RMS of pedestals
not changed

• Run 181920 29-Sep-03 - Run 180808 1-Sep-03, last
  before Shutdown

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Why Blue (Red) modified boards have larger RMS?

• Light Leaks
• Handling of Boards
• Blue modifications

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Blue (Red) Modifications, crate 0x50Increased
RMS Of Pedestals

• Run 182252 4-Oct-03
• Run 180808 1-Sep-03
• Lights off
• 25 of boards have increased RMS (9-1)/32
• RMS of blue board RMS before modifications

15
Green modified boards changed back (red left on)

• Run 182369 7-Oct-03 Run 180808 1-Sep-03
• RMS of board RMS before modifications

16
Green modified boards changed back (red left on)

• Run 182369

17
Green modified boards changed back (red left on)