Plasma panel based ionizing-photon radiation detector

Abstract

A plasma panel based ionizing-photon radiation detector includes an input and output substrate with gamma-ray to free-electron conversion occurring primarily on the input plate and a sealed discharge gas between the substrates. X-electrodes and Y-electrodes are formed on the two substrates and configured to form a plurality of pixels. Impedances are coupled to the X and Y electrodes and a power supply is coupled to the X-electrodes. Discharge event detectors coupled to impedances detect discharge events on the Y electrodes and at the pixel locations, which leads to the detection of ionizing-photon radiation.

1 . An ionizing-photon radiation detector comprising:
 a first substrate;   a second substrate generally parallel to said first substrate and forming a gap with said first substrate;   a gas contained within said gap;   at least one first electrode coupled to said first substrate;   at least one second electrode coupled to said second substrate;   at least one third electrode coupled to said second substrate;   a second impedance coupled to said second electrode;   a third impedance coupled to said third electrode;   a power supply coupled to said first electrode;   a first discharge event detector coupled to said second impedance; and   a second discharge event detector coupled to said third impedance.   
   
   
       2 . The ionizing-photon radiation detector of  claim 1 , wherein said second electrode and said third electrode are paired in close proximity to define at least one pixel. 
   
   
       3 . The ionizing-photon radiation detector of  claim 2 , wherein said first electrode is an X-electrode, said second electrode is a Yc (column)-electrode, and said third electrode is a Yr (row)-electrode. 
   
   
       4 . The ionizing-photon radiation detector of  claim 1 , further comprising:
 at least one first driver coupled to said second electrode; and   at least one second driver coupled to said third electrode.   
   
   
       5 . The ionizing-photon radiation detector of  claim 1 , further comprising:
 time-stamp circuitry coupled to said first discharge event detector and said second discharge event detector that time-stamps discharge events detected by said first discharge event detector and said second discharge event detector.   
   
   
       6 . The ionizing-photon radiation detector of  claim 5 , further comprising:
 discharge event data storage coupled to said time-stamp circuitry for storing coupled discharge events detected by said first discharge event detector and said second discharge event detector that occur at generally the same time.   
   
   
       7 . The ionizing-photon radiation detector of  claim 6 , further comprising:
 sensitivity control coupled to said discharge event data storage for providing feedback information to said power supply and said first and second discharge event detectors.   
   
   
       8 . The ionizing-photon radiation detector of  claim 3 , further comprising a gamma-ray to free-electron emitter layer coupled to said first substrate and defining said X-electrode as an emitter source electrode. 
   
   
       9 . The ionizing-photon radiation detector of  claim 1 , further comprising:
 a hermetic seal coupling said first substrate to said second substrate; and   peripheral edge spacers to define said gap.   
   
   
       10 . The ionizing-photon radiation detector of  claim 1 , further comprising a dielectric layer between said second electrode and said third electrode. 
   
   
       11 . The ionizing-photon radiation detector of  claim 1 , further comprising a first impedance coupled to said first electrode. 
   
   
       12 . An ionizing-photon radiation detector comprising:
 a first substrate;   a second substrate generally parallel to said first substrate and forming a gap with the first substrate;   a gas filling said gap;   an emitter source electrode coupled to said first substrate;   a current directional first and second electrode coupled to said second substrate and defining a pixel centroid;   a first driver, a first current limit impedance and a first pulse detector coupled to said first electrode;   a second driver, a second current limit impedance and a second pulse detector coupled to said second electrode.   
   
   
       13 . The ionizing-photon radiation detector of  claim 12 , further comprising:
 a power supply, an third driver and a third current limit impedance coupled to said emitter source electrode.   
   
   
       14 . The ionizing-photon radiation detector of  claim 13 , wherein said emitter source electrode is an X-electrode, said first electrode is a Yc (column)-electrode, and said second electrode is a Yr (row)-electrode. 
   
   
       15 . The ionizing-photon radiation detector of  claim 13 , further comprising:
 time-stamp circuitry coupled to said first pulse detector and said second pulse detector that time-stamps discharge events detected by said first pulse detector and said second pulse detector.   
   
   
       16 . The ionizing-photon radiation detector of  claim 15 , further comprising:
 discharge event data storage coupled to said time-stamp circuitry for storing coupled discharge events detected by said first pulse detector and said second pulse detector that occur at generally the same time.   
   
   
       17 . The ionizing-photon radiation detector of  claim 16 , further comprising:
 sensitivity control coupled to said discharge event data storage for providing feedback information to said power supply and said first and second pulse detectors.   
   
   
       18 . The ionizing-photon radiation detector of  claim 12 , further comprising:
 a hermetic seal coupling said first substrate to said second substrate; and   peripheral edge spacers that define said gap.   
   
   
       19 . The ionizing-photon radiation detector of  claim 12 , further comprising a dielectric layer between said second electrode and said third electrode. 
   
   
       20 . A method of detecting ionizing-radiation comprising:
 receiving gamma-ray radiation at a first substrate of a plasma panel, said plasma panel having a second substrate;   creating at least one free-electron within said first substrate in response to the received gamma-ray radiation, said creating resulting in an eminence of an electron out of said first substrate and into a gas contained within a gap between said first and second substrates;   causing a gas discharge event at a pixel site of the plasma panel; and   sensing said event at a first pulse detector coupled to a second electrode and at a second pulse detector coupled to a third electrode, wherein said second and third electrodes are coupled to said second substrate of the plasma panel.