Development of a resistive beam position/current monitor for the UMD electron ring

A prototype resistive beam position/current monitor has been developed for the proposed small electron ring at the University of Maryland. It consists of 32 low-inductance resistors which are uniformly distributed around a ceramic gap between two conducting pipes. The resistors are divided into four quadrants and each quadrant has a total resistance of 0.625 Ω. The beam image currents are measured in the four quadrants and the measurement leads to the information about beam position and total beam current. A bench test has been done for the prototype beam position/current monitor. The result shows that the beam position/current monitor gives an accurate total beam current with an error of 2% and satisfactory position information in both radial and azimuthal directions. The rise time of the monitor is measured to be about 1 ns