Up to now, the wave union method can achieve the best timing performance in FPGA-based TDC designs. However, it should be guaranteed in such a structure that the non-thermometer code to binary code （NTH2B） encoding ...Up to now, the wave union method can achieve the best timing performance in FPGA-based TDC designs. However, it should be guaranteed in such a structure that the non-thermometer code to binary code （NTH2B） encoding process should be finished within just one system clock cycle. So the implementation of the NTH2B encoder is quite challenging considering the high speed requirement. Besides, the high resolution wave union TDC also demands that the encoder convert an ultra-wide input code to a binary code. We present a fast improved fat tree encoder （IFTE） to fulfill such requirements, in which bubble error suppression is also integrated. With this encoder scheme, a wave union TDC with 7.7 ps RMS and 3.8 ps effective bin size was implemented in an FPGA from Xilinx Virtex 5 family. An encoding time of 8.33 ns was achieved for a 276-bit non-thermometer code to a 9-bit binary code conversion. We conducted a series of tests on the oscillating period of the wave union launcher, as well as the overall performance of the TDC; test results indicate that the IFTE works well. In fact, in the implementation of this encoder, no manual routing or special constraints were required; therefore, this IFTE structure could also be further applied in other delay-chain-based FPGA TDCs.展开更多
The requirement of a large number of electronic channels poses a big challenge to the further applications of Micro-pattern Gas Detectors （MPGDs）. By using the redundancy that at least two neighboring strips record ...The requirement of a large number of electronic channels poses a big challenge to the further applications of Micro-pattern Gas Detectors （MPGDs）. By using the redundancy that at least two neighboring strips record the signal of a particle, a novel method of encoded multiplexing readout for MPGDs is presented in this paper. The method offers a feasible and easily-extensible way of encoding and decoding, and can significantly reduce the number of readout channels. A verification test was carried out on a 5 cm×5 cm Thick Gas Electron Multiplier （THGEM） detector using a 8 keV Cu X-ray source with 100um slit, where 166 strips were read out by 21 encoded readout channels. The test results show good linearity in its position response, and the spatial resolution root-mean-square （RMS） of the test system is about 260um. This method has potential to build large area detectors and can be easily adapted to other detectors similar to MPGDs.展开更多
针对水利水电行业的特点,阐述了BIM技术(Building Information Modeling)的应用价值。实施BIM技术,将体现可视化、多专业协同、标准化、精细化优势,可以优化设计流程,保证设计深度、提高设计效率、强化设计质量。通过4D模拟,提前规划施...针对水利水电行业的特点,阐述了BIM技术(Building Information Modeling)的应用价值。实施BIM技术,将体现可视化、多专业协同、标准化、精细化优势,可以优化设计流程,保证设计深度、提高设计效率、强化设计质量。通过4D模拟,提前规划施工场地,精心安排施工计划,控制节点工期;可以更好控制投资,监控项目进展、分析反馈数据。通过BIM技术,实现信息共享,对于提高行业整体效率和管理水平具有重要意义。展开更多
基金Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-N27)National Natural Science Foundation of China (11222552)Fundamental Research Funds for Central Universities (WK2030040015)
文摘Up to now, the wave union method can achieve the best timing performance in FPGA-based TDC designs. However, it should be guaranteed in such a structure that the non-thermometer code to binary code （NTH2B） encoding process should be finished within just one system clock cycle. So the implementation of the NTH2B encoder is quite challenging considering the high speed requirement. Besides, the high resolution wave union TDC also demands that the encoder convert an ultra-wide input code to a binary code. We present a fast improved fat tree encoder （IFTE） to fulfill such requirements, in which bubble error suppression is also integrated. With this encoder scheme, a wave union TDC with 7.7 ps RMS and 3.8 ps effective bin size was implemented in an FPGA from Xilinx Virtex 5 family. An encoding time of 8.33 ns was achieved for a 276-bit non-thermometer code to a 9-bit binary code conversion. We conducted a series of tests on the oscillating period of the wave union launcher, as well as the overall performance of the TDC; test results indicate that the IFTE works well. In fact, in the implementation of this encoder, no manual routing or special constraints were required; therefore, this IFTE structure could also be further applied in other delay-chain-based FPGA TDCs.
基金Supported by National Natural Science Foundation of China(11222552,11265003)
文摘The requirement of a large number of electronic channels poses a big challenge to the further applications of Micro-pattern Gas Detectors （MPGDs）. By using the redundancy that at least two neighboring strips record the signal of a particle, a novel method of encoded multiplexing readout for MPGDs is presented in this paper. The method offers a feasible and easily-extensible way of encoding and decoding, and can significantly reduce the number of readout channels. A verification test was carried out on a 5 cm×5 cm Thick Gas Electron Multiplier （THGEM） detector using a 8 keV Cu X-ray source with 100um slit, where 166 strips were read out by 21 encoded readout channels. The test results show good linearity in its position response, and the spatial resolution root-mean-square （RMS） of the test system is about 260um. This method has potential to build large area detectors and can be easily adapted to other detectors similar to MPGDs.
文摘针对水利水电行业的特点,阐述了BIM技术(Building Information Modeling)的应用价值。实施BIM技术,将体现可视化、多专业协同、标准化、精细化优势,可以优化设计流程,保证设计深度、提高设计效率、强化设计质量。通过4D模拟,提前规划施工场地,精心安排施工计划,控制节点工期;可以更好控制投资,监控项目进展、分析反馈数据。通过BIM技术,实现信息共享,对于提高行业整体效率和管理水平具有重要意义。
