Centroid apparatus and method for sub-pixel X-ray image resolution
First Claim
1. An apparatus for detecting X-rays comprising:
- a scintillator which produces light upon being impacted by an X-ray photon, which is referred to as an X-ray photon event;
a photocathode adjacent the scintillator and which emits a plurality of photoelectrons in response to light from the scintillator;
a gas electron multiplier adjacent the scintillator to receive the plurality of photoelectrons and having a plurality of stages;
a two dimensional array of charge collection electrodes positioned to receive photoelectrons emitted by the gas electron multiplier in response to receipt of the plurality of photoelectrons from the scintillator, wherein each charge collection electrode produces an electrical signal indicating a quantity of photoelectrons which have struck that respective charge collection electrode; and
a signal processor which analyzes the electrical signals from a two dimensional matrix of a plurality of the charge collection electrodes in the two dimensional array to determine a location of the X-ray photon event.
2 Assignments
0 Petitions
Accused Products
Abstract
An apparatus for detecting X-rays comprises a scintillator which emits a plurality of photoelectrons upon being impacted by an X-ray photon. The photoelectrons are amplified in a gas electron multiplier and the resultant photoelectrons are accumulated on a two dimensional array of charge collection electrodes. Electrical signals are produced which indicate the quantity of photoelectrons which strike each charge collection electrode. A processor determines a location of the X-ray photon strike by analyzing the spatial distribution of the photoelectrons accumulated by the array of charge collection electrodes. The intensity of the X-ray photon is determined from the number of accumulated photoelectrons.
10 Citations
17 Claims
-
1. An apparatus for detecting X-rays comprising:
-
a scintillator which produces light upon being impacted by an X-ray photon, which is referred to as an X-ray photon event;
a photocathode adjacent the scintillator and which emits a plurality of photoelectrons in response to light from the scintillator;
a gas electron multiplier adjacent the scintillator to receive the plurality of photoelectrons and having a plurality of stages;
a two dimensional array of charge collection electrodes positioned to receive photoelectrons emitted by the gas electron multiplier in response to receipt of the plurality of photoelectrons from the scintillator, wherein each charge collection electrode produces an electrical signal indicating a quantity of photoelectrons which have struck that respective charge collection electrode; and
a signal processor which analyzes the electrical signals from a two dimensional matrix of a plurality of the charge collection electrodes in the two dimensional array to determine a location of the X-ray photon event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. An apparatus for detecting X-rays comprising:
-
a scintillator which produces light upon being impacted by an X-ray photon, which is referred to as an X-ray photon event;
a photocathode adjacent the scintillator and which emits a plurality of photoelectrons in response to light from the scintillator;
a gas electron multiplier adjacent the scintillator to receive the plurality of photoelectrons, the gas electron multiplier having a first stage, a second stage and a third stage wherein the first stage has substantially unity gain to minimize gas scintillated photon and ion feedback to the scintillator and the second and third stages each has a gain between 10 and 100;
a two dimensional array of charge collection electrodes positioned to receive photoelectrons emitted by the gas electron multiplier in response to receipt of the plurality of photoelectrons from the scintillator, wherein each charge collection electrode produces an electrical signal indicating a quantity of photoelectrons which have struck that respective charge collection electrode; and
a signal processor which determines a location of the X-ray photon event by deriving an intensity weighted mean of the electrical signals from a square matrix of charge collection electrodes. - View Dependent Claims (10, 11, 12)
-
-
13. A method for detecting X-rays comprising:
-
providing a scintillator which produces light upon being impacted by an X-ray photon, which impact is referred to as an X-ray photon event;
providing a photocathode which emits a plurality of photoelectrons in response to light from the scintillator;
amplifying the photoelectrons in a gas electron multiplier having a plurality of stages;
receiving, at a two dimensional array of charge collection electrodes, photoelectrons emitted from the gas electron multiplier, wherein each charge collection electrode produces an electrical signal indicating a quantity of photoelectrons which strike respective charge collection electrode; and
determining a location of the X-ray photon event in response to the electrical signals from a two dimensional matrix of a plurality of the charge collection electrodes in the two dimensional array. - View Dependent Claims (14, 15, 16, 17)
-
Specification