Position sensitive detector providing position information with enhanced

Abstract

A position sensitive detector has one or more wedge-and-wedge anode units, each of which has four electrodes on a planar surface arranged in a plurality of sets of four wedge-shaped electrode elements each, with the sets extending across the anode unit. Two of the electrode elements become progressively wider from set to set from one side of the anode unit to the other, while the other two electrode elements become progressively narrower. The respective electrode elements in each set are electrically connected together to complete the four electrodes. The charge measured on each of the four electrodes can be utilized to determine the X and Y coordinates of an event which results in a charge cloud impacting the anode, with redundant information available from the four electrodes. The coordinates calculated using charge information from any three of the electrodes can be compared with information calculated from the charge measured from the fourth electrode and two of the other electrodes, and the two sets of calculations can be compared. If each set of calculations does not yield the same result, two or more events have occurred simultaneously at different positions, and the measured data can be rejected to avoid erroneous data. The electrodes of large arrays of such anode units can be readily connected together to cover a large detector area with a minimal number of data output lines required, and with the capability of determining the position of simultaneous events by taking advantage of the redundant information available from each anode unit.