Apparatus, imaging device and method for detecting X-ray radiation

A method for detecting X-ray photons in a computer tomography scanner, comprising the following steps being performed in an electrical network:

• converting a photon into a charge pulse using a sensor,
• converting the charge pulse into an electrical signal,
• shaping the electrical signal into an electrical pulse,
• comparing the electrical pulse against a threshold using a discriminator,
• deriving an electrical trigger signal from an electrical state of an electrical path of the electrical network, wherein the electrical path is from an output of the sensor to an output of the discriminator;
• and
• performing a switching operation in the electrical path in response to the electrical trigger signal routed by a time delay element, wherein the switching operation disconnects the electrical path that has received an electrical signal caused by the photon, from the sensor after a detection of the photon is indicated by the trigger signal.

An apparatus for detecting X-ray photons in a computer tomography scanner, comprising:

• an electrical network, including:
• a sensor adapted to convert a photon into a charge pulse;
• a first preamplifier adapted to convert the charge pulse into an electrical signal;
• a first shaper adapted to convert the electrical signal into an electrical pulse;
• a first discriminator adapted to compare the electrical pulse against a threshold;
• at least a second discriminator connected in parallel to the first discriminator, wherein the first discriminator and the at least the second discriminator receive different voltage thresholds corresponding to different photon energies;
• a first counter connected to the first discriminator;
• and
• a second counter connected to the second discriminator,
• an electrical path of the electrical network from an output of the sensor to an output of the discriminator, including:
• a switching element adapted to be actuated in response to an electrical trigger signal derived from an electrical state of the electrical path, wherein the electrical trigger signal indicates that the electrical path has received an electrical signal caused by the photon, and the switching element is adapted to disconnect the sensor from the electrical path after a detection of the photon indicated by the trigger signal.