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Photon counting eliminates gain noise, where the proportionality constant between analog signal out and number of photons varies randomly. Thus, the excess noise factor of a photon-counting detector is unity, and the achievable signal-to-noise ratio for a fixed number of photons is generally higher than the same detector without photon counting ...
Ligand K-edge spectroscopy is a spectroscopic technique used to study the electronic structures of metal-ligand complexes. [7] This method measures X-ray absorption caused by the excitation of ligand 1s electrons to unfilled p orbitals ( principal quantum number n ≤ 4 {\displaystyle n\leq 4} ) and continuum states, which creates a ...
Modeling photon propagation with Monte Carlo methods is a flexible yet rigorous approach to simulate photon transport. In the method, local rules of photon transport are expressed as probability distributions which describe the step size of photon movement between sites of photon-matter interaction and the angles of deflection in a photon's trajectory when a scattering event occurs.
In the early 2010s, single-pixel imaging was exploited in fluorescence microscopy, for imaging biological samples. [7] Coupled with the technique of time-correlated single photon counting (TCSPC), the use of single-pixel imaging for compressive fluorescence lifetime imaging microscopy (FLIM) has also been explored. [ 8 ]
Shot noise is easily observable in the case of photomultipliers and avalanche photodiodes used in the Geiger mode, where individual photon detections are observed. However the same noise source is present with higher light intensities measured by any photo detector , and is directly measurable when it dominates the noise of the subsequent ...
Photon statistics is the theoretical and experimental study of the statistical distributions produced in photon counting experiments, which use photodetectors to analyze the intrinsic statistical nature of photons in a light source.
Using smaller image pixels decreases the per-pixel count rate and thus alleviates the demands on pulse resolving time at the expense of requiring more electronics. Partial energy deposition and single photons causing signals in multiple pixels poses another challenge in photon-counting CT. [2]
Dual-energy imaging, i.e. imaging at two energy levels, is a special case of spectral imaging and is still the most widely used terminology, but the terms "spectral imaging" and "spectral CT" have been coined to acknowledge the fact that photon-counting detectors have the potential for measurements at a larger number of energy levels. [2] [3]