Quantum-counting radiation detector
A quantum-counting radiation detector in which signals of individual pixels and signals of combined pixels are evaluated in parallel processing branches and count results are combined in an appropriate manner, thereby reducing the influence of unwanted interference effects for the respective application.
1. A quantum-counting radiation detector, comprising:
an array of detector elements, each of the detector elements being configured to generate a charge quantity as a function of energy of incident radiation quanta, the array of detector elements being divided into groups of adjacent detector elements to form larger detector units;
a first processing stage, allowing a first electrical signal to be supplied for each of the groups, each of the respective first electrical signals being a function of a sum of the generated charge quantities of the respective detector elements of the group; and
a second processing stage, allowing x-ray quanta striking each respective group to be counted by evaluating the respective first electrical signals supplied, in order to obtain a respective first count result for each respective group,
the first processing stage being configured in such a manner to supply a respective second electrical signal as a function of the generated charge quantity of the respective detector element or the respective first subgroup for each respective detector element or for each respective first subgroup of detector elements, into which the groups are divided, and
the second processing stage being configured in such a manner to count the respective radiation quanta striking each respective detector element or each respective first subgroup by evaluating the respective second electrical signals supplied, in order to obtain a second count result for each respective detector element or for each respective first subgroup, and by combining the respective first and second count results to calculate respective image information or a first respective effective signal, wherein the first processing stage and the second processing stage are further configured to process said first electrical signals and said second electrical signals in parallel.
2. The radiation detector of claim 1 , wherein the first processing stage includes a facility for distributing the charge quantity generated by each respective detector element or each respective first subgroup to two separate processing branches, with the generation and evaluation of the first electrical signals taking place in one of the two processing branches and the generation and evaluation of the second electrical signals taking place in the other of the two processing branches.
3. The radiation detector of claim 2 , wherein the second processing stage is configured to combine the count results according to the following formula:
R=R s +w ( R e )* R e ,
where R s is the measured quantum flux of the respective group or the first count result and R e is the measured quantum flux of the respective detector element or the second count result and w corresponds to a weighting function.
4. The radiation detector of claim 3 , wherein the weighting function is determined from a difference between paralysis curves of the individual detector elements and groups of detector elements.
5. The radiation detector of claim 1 , wherein the first processing stage includes a facility for distributing the second electrical signals supplied for each respective detector element or each respective first subgroup to two separate processing branches, with the generation and evaluation of the first electrical signals taking place in one of the two processing branches and evaluation of the second electrical signals taking place in the other of the two processing branches.
6. The radiation detector of claim 5 , wherein the second processing stage is configured to combine the count results according to the following formula:
R=R s +w ( R e )* R e ,
where R s is the measured quantum flux of the respective group or the first count result and R e is the measured quantum flux of the respective detector element or the second count result and w corresponds to a weighting function.
7. The radiation detector of claim 6 , wherein the weighting function is determined from a difference between paralysis curves of the individual detector elements and groups of detector elements.
8. The radiation detector of claim 1 , wherein the second processing stage comprises at least one discriminator and a counting facility for each respective group and for each respective detector element or each respective first subgroup.
9. The radiation detector of claim 8 , wherein the second processing stage includes a number of discriminators for each respective group and for each respective detector element or each respective first subgroup, to allow energy-selective counting of the incident radiation quanta.
10. The radiation detector of claim 8 , wherein the second processing stage is configured to combine the count results according to the following formula:
R=R s +w ( R e )* R e ,
where R s is the measured quantum flux of the respective group or the first count result and R e is the measured quantum flux of the respective detector element or the second count result and w corresponds to a weighting function.
11. The radiation detector of claim 10 , wherein the weighting function is determined from a difference between paralysis curves of the individual detector elements and groups of detector elements.
12. The radiation detector of claim 1 , wherein the second processing stage is configured to combine the count results according to the following formula:
R=R s +w ( R e )* R e ,
where R s is the measured quantum flux of the respective group or the first count result and R e is the measured quantum Mix of the respective detector element or the second count result and w corresponds to a weighting function.
13. The radiation detector of claim 12 , wherein the weighting function is determined from a difference between paralysis curves of the individual detector elements and groups of detector elements.
14. The radiation detector of claim 1 , wherein the first processing stage is configured to supply a (k+2)th electrical signal as a function of the sum of the generated charge quantity of the detector elements of the (k+1)th subgroup for each (k+1)th subgroup of detector elements, into which the kth subgroups are divided, where k=1 . . . n, and wherein the second processing stage is configured to count the radiation quanta striking each (k+1)th subgroup by evaluating the (k+2)th electrical signals supplied, in order to obtain a (k+2)th count result for each (k+1)th subgroup, and calculates a (k+1)th effective signal in each instance by combining the kth effective signals and (k+2)th count results.
15. The radiation detector of claim 1 , wherein the radiation detector is an x-ray detector.