5-FEB-09 Check of the T962 Cryostat
                 Wire Plane Bias Voltage Connections
              -----------------------------------------


                                               Original Rev.  5-FEB-2009
                                                Current Rev.  9-FEB-2009


The connections from the SHV voltage feedthrough down to the wire
planes was tested down in the tunnel on 5-February-2009 before LAr
had been put into the cryostat.  By the time of this test most of
the plumbing had been put on the cryostat but a vacuum had not yet
been pumped on the cryostat.

The HP generator was set for a 2 Hz 10 Vpp output square wave.
Note that the output level on the generator itself is set for
5 Vpp but because it is not loaded with a 50 Ohm termination
the generator delivers 10 Vpp at its output.  At the external
readout cable all 16 signals are joined together and run through
about 8 to 10 feet of RG58 to the scope which is set to have
a 1 Meg Ohm input.  The external readout cable signal is plugged
into Ch #1 of the scope.  The HP generator is plugged into Ch #4
of the scope and plugged into one of the 4 Bias Voltage SHV
feedthrough connectors.


Scope_Pict_05

  External Readout Cable I 1:16  i.e. the Shield Plane Cable 16 signals
  shows a 710 mV 0-Pk signal with the
  Square Wave plugged into the 3:00 SHV feedthrough, i.e. New Shield.


Scope_Pict_06

  External Readout Cable I 1:16  i.e. the Shield Plane Cable 16 signals
  shows about a 25 mV 0-Pk signal with the
  Square Wave plugged into the 6:00 SHV feedthrough, i.e. Induction.


Scope_Pict_07

  External Readout Cable I 17:32  i.e. the Shield Plane Cable 8 signals
  shows about a 640 mV 0-Pk signal with the
  Square Wave plugged into the 3:00 SHV feedthrough, i.e. New Shield.


Scope_Pict_08

  External Readout Cable 9 1:16,  signal feedthrough J4,
  the middle of the Collection Plane, 16 signals
  shows about a 452 mV 0-Pk signal with the
  Square Wave plugged into the 12:00 SHV feedthrough, i.e. Collection.
  Note that I should have used a longer period square wave for this test.


Scope_Pict_09

  External Readout Cable IIII 1:16,  signal feedthrough J9,
  the middle of the Induction Plane, 16 signals
  shows about a 452 mV 0-Pk signal with the
  Square Wave plugged into the 6:00 SHV feedthrough, i.e. Induction.
  Note that I should have used a longer period square wave for this test.


Scope_Pict_10

  External Readout Cable IIII 1:16,  signal feedthrough J9,
  the middle of the Induction Plane, 16 signals
  shows about a 2.5 mV 0-Pk signal with the
  Square Wave plugged into the 3:00 SHV feedthrough, i.e. New Shield.


Scope_Pict_11

  External Readout Cable IIII 1:16,  signal feedthrough J9,
  the middle of the Induction Plane, 16 signals
  shows about a 2.0 mV 0-Pk signal with the
  Square Wave plugged into the 12:00 SHV feedthrough, i.e. Collection.



From the above test it is determined that looking at the front of the
Bias Voltage Feedthrough flange the following are the connections to
the Wire Planes.


          SHV
       Connector     Original       Current
        Location       Label       Function
       ---------    ----------    -------------
         12:00      Collection     Collection
          3:00         Spare         Shield
          6:00       Induction      Induction
          9:00         Shield     No-Connection