US 4,465,933 A · Wire chamber radiation detector with discharge control

Abstract

A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

Claims14

Dependent claims

In a wire chamber for detecting charged particles or other ionizing radiations, having first, second and third spaced apart electrodes, said first and second electrodes defining an ignition region wherein said charged particles initiate localized primary electrical discharges, said second and third electrodes defining a memory region wherein localized glow discharges are initiated by said primary discharges, and having means for detecting the spatial locations of said glow discharges within said memory region, and high voltage supply means for applying a high voltage pulse across said first and second electrodes, the improvement comprising:

discharge limiting means for restricting said primary discharges to the avalanche stage of electrical discharge progression,
said discharge limiting means including a fourth electrode situated between said first and second electrodes in spaced apart relationship to each thereof, and
means for applying a discharge control voltage pulse to said fourth electrode concurrently with application of said high voltage pulse across said first and second electrodes.

In a wire chamber for detecting and locating charged particles or the like, the combination comprising:

a high voltage electrode, a memory electrode spaced therefrom and an intermediate electrode situated between said high voltage electrode and memory electrode and spaced apart from each thereof, at least said intermediate electrode being a grid formed by a plurality of parallel conductors spaced apart to provide passages therebetween,
means for applying high voltage pulses to said high voltage electrode to initiate localized primary electrical discharges between said high voltage electrode and said intermediate electrode in response to passages of said charged particles or the like therebetween,
means for applying a relatively small voltage of longer duration to said memory electrode to initiate and maintain localized glow discharges therebetween at locations corresponding to the locations of said primary discharges,
means for reading out the spatial coordinates of said glow discharges,
a discharge control grid disposed between said high voltage electrode and said intermediate electrode in spaced relationship from each thereof, and
means for applying a control voltage pulse to said discharge control grid concurrently with application of said high voltage pulse to said high voltage electrode, said control voltage pulse being of lesser magnitude than said high voltage pulse.

3 more elements

Dependencies are inferred from the claim text.

Wire chamber radiation detector with discharge control

Life of this patent

Wire chamber radiation detector with discharge control

Life of this patent

Abstract

Claims14