P. King, R. Abbott

ITMY H2 Scattered Light Photodiode Readout Electronics:

Put in 4 Melles Griot adjustable transimpedance amplifiers next to BSC8 on the floor under the cable tray (gain is presently set to 20nA full scale).  The installation started with a 25 pin D-sub cable on flange number F1, subflange 3, bottom D-sub.  The cable runs through the tray for a bit, then drops down to floor level in the cable tray leading toward the Y-end.  A 25 pin D-sub to (4) BNC connector breakout cable is used to fan out the D-sub to each of the transimpedance amplifiers.  The cathode of each photodiode is on the center conductor of the BNC connector, the anode is on the outer shield.

Four BNC cables run in the tray under the beam tube over to the H2 PEM chassis.  The BNC cables were reused out of a pile of old squeezer cables, so they have the prefix SQZ on their cable label.  Here's the breakdown:

SQZ:ADC4 - Connects the channel labeled 29 on the front of the PEM chassis to PD head 1
SQZ:ADC9 - Connects the channel labeled 30 on the front of the PEM chassis to PD head 2
SQZ:ADC15 - Connects the channel labeled 31 on the front of the PEM chassis to PD head 3
SQZ:ADC16 - Connects the channel labeled 32 on the front of the PEM chassis to PD head 4

The channel numbers on the front of the PEM chassis are 1 to 32, whereas the channel names are offset in a 0 to 31 format.  Next we need to view the channels in Data Viewer (and or a scope) for h2pemIO/LVEA, channels 28, 29, 30, 31 to see how noisy things are.