摘要 |
<p>Zero-Bias Gridded Gun A gun for a linear-beam electron tube has a control grid for modulating the beam current which consists of an array of conductive web elements whose spacing from each other is much larger than their spacing from the concave emissive surface of the cathode. It was found that when this condition is met, the grid can be operated at cathode potential while beam current is being drawn without distorting the electric accelerating field enough to ruin the focusing of the beam. Thus, when the grid is used to pulse the beam current on and off, it can have zero bias in the "on" condition, whereby the pulse modulator can be greatly simplified.</p> |