There are 4 quadrupole magnets http://en.wikipedia.org/wiki/Quadrupole_magnet located on our accelerator.

These magnets and their control power supplies have been upgraded to computer control from the original potentiometer control.

Each quadrupole magnet has 2 power supplies designated QuadA and QuadB with independent current adjustments.

A sample computer control window is shown below.

Ideally, the A and B currents should be equal to focus a symetric beam entering the quadrupole on its center axis.

The computer control window displays a graph window with QuadA current indicated on the X-Axis and the QuadB current indicated on the Y-Axis.

The diagonal line is the locus of points A = B for reference.

The QuadA and QuadB currents are adjusted by moving the bullseye cross hair graphic. The bullseye is initially adjustible in the “Grab” mode.

The “Grab” mode allows you to set the mouse pointer over the bullseye and while depressing the left mouse button, drag the bullseye to another set of A and B current values.