The Pickoff Card

The VXI Pickoff Card

The large 50-conductor grey cables run between the Slope Box on each detector to the Pickoff cards in the VXI crates.

The VXI Pickoff Card receives the single-ended signals for the Ge Center, Ge Sides, and BGO segments from the Slope Box. The VXI pickoff converts these to differential signal format before sending them to the digitizer.

VXI Pickoff Card Features

There are three gain range options (jumper selectable from the bottom of the pickoff card) for the Ge Center: 2, 5, 10 MeV

There is a fixed Preamp Reset Clamp that drives the Ge Center back to baseline after a preamp reset. This sometimes has known oscillation problems (ringing) that can hinder resolution.

There is an analog output on the VXI board. This LEMO output is shaped similar to a NIM Spectroscopy Amplifier, it is NOT what gets sent to the digitizer.