A new Digital Pulse Processing（DPP） module has been developed, based on a domino ring sampler version 4 chip（DRS4）, with good time resolution for La Br3 detectors, and different digital timing analysis methods for...A new Digital Pulse Processing（DPP） module has been developed, based on a domino ring sampler version 4 chip（DRS4）, with good time resolution for La Br3 detectors, and different digital timing analysis methods for processing the raw detector signals are reported. The module, composed of an eight channel DRS4 chip, was used as the readout electronics and acquisition system to process the output signals from XP20D0 photomultiplier tubes（PMTs）. Two PMTs were coupled with La Br3 scintillators and placed on opposite sides of a radioactive positron22 Na source for 511 ke V γ-ray tests. By analyzing the raw data acquired by the module, the best coincidence timing resolution is about 194.7 ps（FWHM）, obtained by the digital constant fraction discrimination（d CFD） method,which is better than other digital methods and analysis methods based on conventional analog systems which have been tested. The results indicate that it is a promising approach to better localize the positron annihilation in positron emission tomography（PET） with time of flight（TOF）, as well as for scintillation timing measurement,such as in TOF-？E and TOF-E systems for particle identification, with picosecond accuracy timing measurement.Furthermore, this module is more simple and convenient than other systems.展开更多
The ranging accuracy of a pseudo-noise ranging system is mainly decided by range jitter and time delay discrimination. Many factors can affect the ranging accuracy, one of which is the chip rate. In digital signal pro...The ranging accuracy of a pseudo-noise ranging system is mainly decided by range jitter and time delay discrimination. Many factors can affect the ranging accuracy, one of which is the chip rate. In digital signal processing, the time delay discrimination and autocorrelation function of sampled ranging sequences of different chip rates are very different. An approximation simulation model is established according to an in-phase quadrature (I/Q) correlator which is used to evaluate the time delay. Simulation results of the range jitter and time delay discrimination show that the chip rate which provides a non-integer sample-to-chip rate ratio can achieve a higher ranging accuracy, and some test results validate the simulation model. In some design missions, the simulation results may help to select an optimum sample-to-chip rate ratio to satisfy the design requirement on the ranging accuracy.展开更多
基金Supported by the Science Foundation of the Chinese Academy of Sciences(210340XBO)National Natural Science Foundation of China(11305233,11205222)+2 种基金General Program of National Natural Science Foundation of China(11475234)Specific Fund of National Key Scientific Instrument and Equipment Development Project(2011YQ12009604)Joint Fund for Research Based on Large-Scale Scientific Facilities(U1532131)
文摘A new Digital Pulse Processing（DPP） module has been developed, based on a domino ring sampler version 4 chip（DRS4）, with good time resolution for La Br3 detectors, and different digital timing analysis methods for processing the raw detector signals are reported. The module, composed of an eight channel DRS4 chip, was used as the readout electronics and acquisition system to process the output signals from XP20D0 photomultiplier tubes（PMTs）. Two PMTs were coupled with La Br3 scintillators and placed on opposite sides of a radioactive positron22 Na source for 511 ke V γ-ray tests. By analyzing the raw data acquired by the module, the best coincidence timing resolution is about 194.7 ps（FWHM）, obtained by the digital constant fraction discrimination（d CFD） method,which is better than other digital methods and analysis methods based on conventional analog systems which have been tested. The results indicate that it is a promising approach to better localize the positron annihilation in positron emission tomography（PET） with time of flight（TOF）, as well as for scintillation timing measurement,such as in TOF-？E and TOF-E systems for particle identification, with picosecond accuracy timing measurement.Furthermore, this module is more simple and convenient than other systems.
基金Project supported by the National Natural Science Foundation of China (No. 60904090)the Postdoctoral Science Foundation of China (No. 20080431306)the Special Postdoctoral Science Foundation of China (No. 20081458)
文摘The ranging accuracy of a pseudo-noise ranging system is mainly decided by range jitter and time delay discrimination. Many factors can affect the ranging accuracy, one of which is the chip rate. In digital signal processing, the time delay discrimination and autocorrelation function of sampled ranging sequences of different chip rates are very different. An approximation simulation model is established according to an in-phase quadrature (I/Q) correlator which is used to evaluate the time delay. Simulation results of the range jitter and time delay discrimination show that the chip rate which provides a non-integer sample-to-chip rate ratio can achieve a higher ranging accuracy, and some test results validate the simulation model. In some design missions, the simulation results may help to select an optimum sample-to-chip rate ratio to satisfy the design requirement on the ranging accuracy.
