Mother Board Description:
The Mother Boards receive signals from the summing boards and transfer them to
cables which carry the signals through the feedthrough to the front-end
electronics for further processing. In addition, the mother boards receive
and distribute calibration pulses to all channels through a series of
resistive networks.
Each mother board covers a region
x
= 0.2 x 0.2.
The mother boards located in the front of the module (along the inner
radii) process the information from the strips. There are seven front mother
boards in eta for each barrel in a given unit of phi
( = 0.2).
These seven boards cover the pseudo rapidity region of 0 to 1.4. In addition,
there is an eighth special front mother board to process the signals from
the barrel-end region ( = 1.4-1.475).
The mother boards in the back region (located along the outer radii of the
module) also have seven mother boards in a given phi interval, which
process the signals from the middle and back layer. Hence
a total of 15 mother boards per barrel per unit phi (Delta_Phi=0.2) are
needed. These 15 mother boards geometrically differ from each other
as the electrode connectors as Delta_z (and hence the electrode connector
spacing) increases with increasing rapidity.
- Coverage of each mother board =
x
= 0.2 x 0.2.
- Number of types of mother boards = 15 (8 front, 7 back)
- Number of boards needed per type per barrel = 32
- Number of boards needed per type for the full barrel = 64
- Total number of mother boards needed for the barrel = 960
Channels processed by each mother boards:
- Front mother boards (|| < 1.4) = 128
strip channels
- Front mother boards (|| > 1.4) = 32
strip channels
- Back mother boards (|| < 1.2)
64 middle and 32 back channels
- Back mother boards (|| > 1.2)
64 middle and 16 back channels
- Total number of channel per barrel per unit phi interval =
928 strip + 448 middle + 208 back = 1584 channels
- Total number of channels = 1584 x 32 x 2 = 101376.
Components on the mother boards include:
- A Mill-Max open ended receptacle to receive the signal from the SB.
- A 2x8 signal socket to provide connection to the signal cables.
- A 2x4 calibration socket to receive calibration pulses.
- Long Pins to connect the Mother Board to the Summing Board.
- A custom made resistive network package to distribute the calibration
pulse to all read out channels
- Termination resistors to minimize the sensitivity to the length of the
routes on the calibration pulses.
Cross talk measurements on the mother board and the effect of using
sockets .
Uniformity studies on back mother boards.
More information is available on: