We present a design for an adaptive gain phase-locked loop （PLL） that features fast acquisition,low jitter,and wide tuning range. A dual-edge-triggered phase frequency detector （PFD） and a self-regulated voltage c...We present a design for an adaptive gain phase-locked loop （PLL） that features fast acquisition,low jitter,and wide tuning range. A dual-edge-triggered phase frequency detector （PFD） and a self-regulated voltage controlled oscillator （VCO） are employed in this design to realize the aforementioned properties. Measured results show that the experimental chip, implemented in a standard 0.5μm 5V CMOS logic process, has an acquisition time of about 150ns at 37% frequency variation and an output RMS jitter of 39ps at 640MHz.（dual-edge-triggered phase frequency detector）展开更多
The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the refle...The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the reflectometer.We present a simple method, using cubic spline interpolation to resample the spectrum with a high resolution,to extend the measurable transparent film thickness. A large measuring range up to 385 m in optical thickness is achieved with the commonly used system. The numerical calculation and experimental results demonstrate that using the FFT method combined with cubic spline interpolation resampling in reflectrometry, a simple,easy-to-operate, economic measuring system can be achieved with high measuring accuracy and replicability.展开更多
Objective A three-dimensional position-sensitive fast neutron spectrometer is designed to measure fast neutron spectrum over 10 MeV.Methods The detector consists of a 16×16 mutually perpendicular plastic scintill...Objective A three-dimensional position-sensitive fast neutron spectrometer is designed to measure fast neutron spectrum over 10 MeV.Methods The detector consists of a 16×16 mutually perpendicular plastic scintillation fiber array coupled to 2×2 Hamamatsu H8500C position-sensitive photomultiplier tubes by optical fibers.The fiber array is fabricated with 0.5 mm×3 mm fibers and 3-mm square fibers.Results Due to the combined application of different sizes of fibers,the detector can broaden energy dynamic range and meanwhile have good detection efficiency.The method of the combined application of different sizes of plastic fibers in the array may provide a solution to measure wider energy range of solar neutrons.Conclusion In this paper,we used FLUKA to simulate the performance of the detector model and report the results of experimental studies with neutrons from a pulsed D-T neutron.展开更多
文摘We present a design for an adaptive gain phase-locked loop （PLL） that features fast acquisition,low jitter,and wide tuning range. A dual-edge-triggered phase frequency detector （PFD） and a self-regulated voltage controlled oscillator （VCO） are employed in this design to realize the aforementioned properties. Measured results show that the experimental chip, implemented in a standard 0.5μm 5V CMOS logic process, has an acquisition time of about 150ns at 37% frequency variation and an output RMS jitter of 39ps at 640MHz.（dual-edge-triggered phase frequency detector）
基金Supported by the National Natural Science Foundation of China under Grant No 11604115the Educational Commission of Jiangsu Province of China under Grant No 17KJA460004the Huaian Science and Technology Funds under Grant No HAC201701
文摘The reflectometry is a common method used to measure the thickness of thin films. Using a conventional method,its measurable range is limited due to the low resolution of the current spectrometer embedded in the reflectometer.We present a simple method, using cubic spline interpolation to resample the spectrum with a high resolution,to extend the measurable transparent film thickness. A large measuring range up to 385 m in optical thickness is achieved with the commonly used system. The numerical calculation and experimental results demonstrate that using the FFT method combined with cubic spline interpolation resampling in reflectrometry, a simple,easy-to-operate, economic measuring system can be achieved with high measuring accuracy and replicability.
文摘Objective A three-dimensional position-sensitive fast neutron spectrometer is designed to measure fast neutron spectrum over 10 MeV.Methods The detector consists of a 16×16 mutually perpendicular plastic scintillation fiber array coupled to 2×2 Hamamatsu H8500C position-sensitive photomultiplier tubes by optical fibers.The fiber array is fabricated with 0.5 mm×3 mm fibers and 3-mm square fibers.Results Due to the combined application of different sizes of fibers,the detector can broaden energy dynamic range and meanwhile have good detection efficiency.The method of the combined application of different sizes of plastic fibers in the array may provide a solution to measure wider energy range of solar neutrons.Conclusion In this paper,we used FLUKA to simulate the performance of the detector model and report the results of experimental studies with neutrons from a pulsed D-T neutron.
