FPGA implementation of digital constant fraction algorithm with fractional delay for optimal time resolution

Jager, M. F.; Butz, T.

doi:10.1016/j.nima.2012.01.022

Cited by 10 publications

(2 citation statements)

References 4 publications

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“…The variable delay that is necessary for different pulse shapes to obtain the best timing resolution makes its use even more difficult [13]–[14]. Although digital CFDs can be implemented inside an FPGA and can use variable delay lengths, this implementation needs a very fast analog-to-digital converter (ADC), which is power hungry and expensive [6], [15]. An LED with a low-level threshold applied to the leading edge of the signal is the simplest time pick-off method.…”

Section: Introductionmentioning

confidence: 99%

A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators

Schmall

Judenhofer

et al. 2017

IEEE Trans. Radiat. Plasma Med. Sci.

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The leading edge timing pick-off technique is the simplest timing extraction method for PET detectors. Due to the inherent time-walk of the leading edge technique, corrections should be made to improve timing resolution, especially for time-of-flight PET. Time-walk correction can be done by utilizing the relationship between the threshold crossing time and the event energy on an event by event basis. In this paper, a time-walk correction method is proposed and evaluated using timing information from two identical detectors both using leading edge discriminators. This differs from other techniques that use an external dedicated reference detector, such as a fast PMT-based detector using constant fraction techniques to pick-off timing information. In our proposed method, one detector was used as reference detector to correct the time-walk of the other detector. Time-walk in the reference detector was minimized by using events within a small energy window (508.5 – 513.5 keV). To validate this method, a coincidence detector pair was assembled using two SensL MicroFB SiPMs and two 2.5 mm × 2.5 mm × 20 mm polished LYSO crystals. Coincidence timing resolutions using different time pick-off techniques were obtained at a bias voltage of 27.5 V and a fixed temperature of 20 °C. The coincidence timing resolution without time-walk correction were 389.0 ± 12.0 ps (425 –650 keV energy window) and 670.2 ± 16.2 ps (250–750 keV energy window). The timing resolution with time-walk correction improved to 367.3 ± 0.5 ps (425 – 650 keV) and 413.7 ± 0.9 ps (250 – 750 keV). For comparison, timing resolutions were 442.8 ± 12.8 ps (425 – 650 keV) and 476.0 ± 13.0 ps (250 – 750 keV) using constant fraction techniques, and 367.3 ± 0.4 ps (425 – 650 keV) and 413.4 ± 0.9 ps (250 – 750 keV) using a reference detector based on the constant fraction technique. These results show that the proposed leading edge based time-walk correction method works well. Timing resolution obtained using this method was equivalent to that obtained using a reference detector and was better than that obtained using constant fraction discriminators.

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Section: Introductionmentioning

confidence: 99%

A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators

Schmall

Judenhofer

et al. 2017

IEEE Trans. Radiat. Plasma Med. Sci.

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“…The TDPAC set-up mounted online consisted of four LaBr 3 gamma detectors with good energy resolution (11.6% at 84.1 keV and 3.0% at 637 keV) and time resolution of 800 ps for the selected cascade. Data acquisition was performed with the digital and FPGA signal processing DIGIPAC setup [18][19][20]. The detectors were positioned in a plane perpendicular to the direction of the radioactive beam, each detector placed at ±90 • and 180 • with respect to the others, as shown in fig.…”

mentioning

confidence: 99%

The ^68m Cu/ ⁶⁸ Cu isotope as a new probe for hyperfine studies: The nuclear moments

Fenta

Pallada

Correia

et al. 2016

EPL

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The 68m Cu/ 68 Cu isotope as a new probe for hyperfine studies: The nuclear moments View the table of contents for this issue, or go to the journal homepage for more 2016 EPL 115 62002 (http://iopscience.iop. rg/0 95-5075/115/6 620 2) Ho e S arch Collec ions Jour als bout ontact us My OP cience You may also be interested in:TDPA and -MR appli ations in chemistr a d bioc emistry tti a Jancso, J ao G Co reia, Alexa der Gott erg et l. The on l ne low e p ratur n clear ori ntation faci it NICOLE T Ohtsub , S Roc ia, N J Ston t al. Recent dev lopme ts in low-tem erature nu lear orientation D Brewer Expl ring solid state ph sics pr perti s with radi acti e sotopes oris Forke -Wirth Su fa e science usi g radioact ve ions t I OLDE: fr m m tal s rf ces to 2-dimen ion l mater al

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Digital Radiation Measurement Systems

2017

Signal Processing for Radiation Detectors

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FPGA implementation of digital constant fraction algorithm with fractional delay for optimal time resolution

Cited by 10 publications

References 4 publications

A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators

A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators

The ^68m Cu/ ⁶⁸ Cu isotope as a new probe for hyperfine studies: The nuclear moments

Digital Radiation Measurement Systems

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