pad plane map
There are 128 sticks in the TPC. Each stick is located perpendicular to the beam direction and there are two sticks to cover the width of the TPC. One stick enters from each side of the TPC. The picture below is the view from the top of the TPC. For analysis the quadrant is not something you should have to use. The quadtrant is just for readout and use in the DAQ. You can simply use the location to know where the data is located. The numbers on the sides show the location numbers that the sticks read from the pad plane and are reported in the data stream.
Two rows of pads are readout by one stick. The number of the pad in the data stream is set as shown in the picture below.