Position sensitive solid-state photomultipliers, systems and methods

Abstract

An integrated silicon solid state photomultiplier (SSPM) device includes a pixel unit including an array of more than 2×2 p-n photodiodes on a common substrate, a signal division network electrically connected to each photodiode, where the signal division network includes four output connections, a signal output measurement unit, a processing unit configured to identify the photodiode generating a signal or a center of mass of photodiodes generating a signal, and a global receiving unit.

1 . An integrated silicon solid state photomultiplier (SSPM) device operable in a Geiger mode, the device comprising:
 a pixel unit including an array of more than 2×2 p-n micro-pixels on a common substrate;   a signal division network electrically coupled to each micro-pixel, the signal division network including four output connections each for providing an output signal;   a signal output measurement unit configured to measure the output signal from each output connection;   a processing unit configured to process the output signals so as to identify the micro-pixel generating a signal or a center of mass of micro-pixels generating a signal, and   a global signal receiving unit comprising a preamplifier electrically coupled in series with a capacitor, wherein the capacitor is electrically coupled to the micro-pixels.   
     
     
         2 . The device of  claim 1 , wherein the signal division network further includes a quenching circuit comprising at least one of a resistive network, a capacitive network, and an inductive network, the quenching circuit being configured to terminate Geiger discharges from the micro-pixels. 
     
     
         3 . The device of  claim 1 , wherein the signal division network further includes a two-dimensional array of elements. 
     
     
         4 . The device of  claim 1 , wherein the signal division network further includes two linear arrays of elements. 
     
     
         5 . The device of  claim 1 , wherein the global signal receiving unit is configured to obtain a global signal from a common electrode. 
     
     
         6 . The device of  claim 5 , wherein the global signal is obtained by summing four position information signals. 
     
     
         7 - 10 . (canceled) 
     
     
         11 . The device of  claim 1 , wherein the signal output measurement unit includes a resistive element and a preamplifier electrically coupled to each of the four output connections. 
     
     
         12 . A radiation detection system comprising:
 an integrated silicon solid state photomultiplier (SSPM) device configured for operation in a Geiger mode, the SSPM device including:   a pixel unit including an array of more than 2×2 p-n Geiger photodiodes (GPDs) on a common substrate,   a signal division network electrically coupled to each GPD, the signal division network including four output connections each for providing an output signal,   means for measuring the output signal from each output connection;   means for processing the output signals so as to identify the GPD generating a signal or a center of mass of GPDs generating a signal, and   means for obtaining a global signal; and   a scintillator optically coupled to the SSPM device.   
     
     
         13 . The system of  claim 12  wherein the scintillator comprises individual elements matched to the geometry of the integrated silicon SSPM. 
     
     
         14 . The system of  claim 12  wherein the scintillator comprises a pixilated microcolumnar scintillator. 
     
     
         15 . The system of  claim 12  wherein the scintillator comprises a substantially continuous scintillator. 
     
     
         16 . A radiation detection system comprising:
 an array of integrated silicon SSPM devices operable in a Geiger mode,   wherein each SSPM device comprises a plurality of pixel units, each pixel unit comprising an array of more than 2×2 p-n GPDs on a common substrate,   wherein the array of integrated SSPM devices comprises an assembly of single pixels.   
     
     
         17 . A combined PET/MRI imaging system, comprising:
 a main magnet for use in MRI imaging;   an RF coil disposed in the main magnet for use in MRI imaging; and   a PET scanner disposed between the main magnet and the RF coil for use in PET imaging, the PET scanner comprising the integrated silicon solid state photomultiplier device of  claim 1 .   
     
     
         18 . A method for detecting radiation, the method comprising:
 providing a system including a pixel unit having an array of more than 2×2 p-n micro-pixels on a common substrate, wherein the system is operably coupled to a scintillator;   providing an output signal to each of four output connections, wherein each output signal is generated based on signals generated from the micro-pixels;   measuring the output signal from each output connection;   
       processing the output signals so as to identify the micro-pixel generating a signal or a center of mass of micro-pixels generating a signal;
 obtaining a global signal from a common electrode by summing four position information signals, wherein the position information signals are based on the output signals; and 
 outputting the global signal to reconstruct an image for display. 
 
     
     
         19 . The method of  claim 18 , further comprising terminating Geiger discharges from the micro-pixels.