Appendix F: Detector Mathematics—Pileup
At most storage rings, there are so many buckets filled that the time between buckets
is short compared to the processing time of the detection system. The photons can
therefore be considered to arrive at random times. Any system that counts photons
therefore has to consider what happens when two photons arrive at nearly the same
time. There is a finite time called the “deadtime” during which a second photon
cannot be properly processed. There are two kinds of deadtime (Fig. F.1):
[1] Nonextending or nonparalyzable
[2] Extending or paralyzable
Fig. F.1 Comparison of
nonextending and extending
deadtime responses
© Springer Nature Switzerland AG 2020
S. P. Cramer, X-Ray Spectroscopy with Synchrotron Radiation, Biological and Medical
Physics, Biomedical Engineering, https://doi.org/10.1007/978-3-030-28551-7
329
At most storage rings, there are so many buckets filled that the time between buckets
is short compared to the processing time of the detection system. The photons can
therefore be considered to arrive at random times. Any system that counts photons
therefore has to consider what happens when two photons arrive at nearly the same
time. There is a finite time called the “deadtime” during which a second photon
cannot be properly processed. There are two kinds of deadtime (Fig. F.1):
[1] Nonextending or nonparalyzable
[2] Extending or paralyzable
Fig. F.1 Comparison of
nonextending and extending
deadtime responses
© Springer Nature Switzerland AG 2020
S. P. Cramer, X-Ray Spectroscopy with Synchrotron Radiation, Biological and Medical
Physics, Biomedical Engineering, https://doi.org/10.1007/978-3-030-28551-7
329