Multi-pixel x-ray source with tungsten-diamond transmission target

Abstract

A multi-pixel x-ray source is provided. The x-ray source includes a plurality of transmission target assemblies. The transmission target assembly includes a tungsten target and a diamond substrate. The substrate includes a first transmission surface and a second transmission surface opposite first transmission surface. The substrate further includes a first side surface and a second side surface disposed between the first and second transmission surfaces. The target covers the first transmission surface of the substrate. The transmission target assembly further includes a base. The base surrounds the first and second side surfaces of substrate, exposing a collimator surface of the second transmission surface and the target. The transmission target assembly is configured to transmit x-ray generated by the target through the target and the substrate.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . A transmission target assembly, comprising:
 a substrate, wherein the substrate comprises:
 a first transmission surface; 
 a second transmission surface opposite the first transmission surface, the second transmission surface including a collimator surface; 
 a first side surface; and 
 a second side surface, the first and second side surfaces being disposed between and connecting the first and second transmission surfaces; 
   a target covering at least a portion of the first transmission surface of the substrate;   and   a base, wherein the base surrounds the first and second side surfaces and a portion of the second transmission surface such that the collimator surface of the second transmission surface and the target are exposed.   
     
     
         3 . The transmission target assembly of  claim 2 , wherein the substrate comprises diamond. 
     
     
         4 . The transmission target assembly of  claim 2 , wherein the target comprises tungsten. 
     
     
         5 . The transmission target assembly of  claim 2 , wherein the transmission target assembly is configured to operate in a pulse mode. 
     
     
         6 . The transmission target assembly of  claim 2 , wherein the transmission target assembly is optimized by a Monte Carlo simulation. 
     
     
         7 . The transmission target assembly of  claim 6 , wherein the Monte Carlo simulation comprises a finite element thermal simulation of a temperature distribution on the transmission target assembly. 
     
     
         8 . The transmission target assembly of  claim 2 , wherein the target comprises a thickness in a range from approximately 5 μm to approximately 6 μm, and the transmission target assembly is configured to receive electronic beams having an energy in a range from approximately 60 kVp to approximately 140 kVp. 
     
     
         9 . The transmission target assembly of  claim 2 , wherein the transmission target assembly is configured to transmit x-rays through the target and through the substrate at the collimator surface of the substrate. 
     
     
         10 . The transmission target assembly of  claim 9 , wherein the base of the transmission target assembly comprising a collimator edge, the collimator edge forming a collimator and configured to guide the x-rays toward a fluence detector. 
     
     
         11 . A multi-pixel x-ray source, comprising:
 an anode including a target assembly, the target assembly comprising:
 a substrate; and 
 a target disposed on the substrate, the target comprising a plurality of focal spots, wherein the anode is configured to emit x-rays from the plurality of focal spots; and 
   a housing enclosing the anode, the housing further comprising a viewport disposed on the housing, the viewport configured to estimate a temperature of the plurality of focal spots based on a color of the plurality of focal spots.   
     
     
         12 . The multi-pixel x-ray source of  claim 11 , wherein the target assembly is a transmission target assembly. 
     
     
         13 . The multi-pixel x-ray source of  claim 11 , wherein the target assembly is a reflection target assembly. 
     
     
         14 . The multi-pixel x-ray source of  claim 13 , wherein the substrate of the target assembly comprises annealed pyrolytic graphite (APG). 
     
     
         15 . The multi-pixel x-ray source of  claim 13 , wherein the substrate of the target assembly comprises pyrolytic graphite (PG), and an a-b plane of the PG of the substrate is aligned with a cross-section of the housing. 
     
     
         16 . A multi-pixel x-ray source having a plurality of target assemblies, each target assembly comprising:
 a target comprising a plurality of tungsten layers laminated in pyrolytic graphite (PG); and   a base comprising PG, the base including a lateral surface, wherein the target is disposed on the lateral surface of the base,   wherein heat is conducted in a direction of starting from the target toward the base.   
     
     
         17 . The multi-pixel x-ray source of  claim 16 , wherein the PG comprises annealed pyrolytic graphite (APG). 
     
     
         18 . The multi-pixel x-ray source of  claim 16 , the PG including an a-b plane, wherein the a-b plane of the PG is aligned with the heat conduction direction of each target assembly. 
     
     
         19 . The multi-pixel x-ray source of  claim 18 , wherein each target assembly comprises an APG plate having its a-b plane perpendicular to a direction of its thickness, and the plurality of target assemblies are stacked together along the direction of the thickness of the APG plate. 
     
     
         20 . The multi-pixel x-ray source of  claim 16 , wherein each tungsten layer of the target is deposited in the PG by chemical vapor deposition (CVD).