Vertical displacement event（VDE） is a big challenge to the existing tokamak equipment and that being designed. As a Chinese next-step tokamak, the Chinese Fusion Engineering Test Reactor（CFETR） has to pay attentio...Vertical displacement event（VDE） is a big challenge to the existing tokamak equipment and that being designed. As a Chinese next-step tokamak, the Chinese Fusion Engineering Test Reactor（CFETR） has to pay attention to the VDE study with full-fledged numerical codes during its conceptual design. The tokamak simulation code（TSC） is a free boundary time-dependent axisymmetric tokamak simulation code developed in PPPL, which advances the MHD equations describing the evolution of the plasma in a rectangular domain. The electromagnetic interactions between the surrounding conductor circuits and the plasma are solved self-consistently. The TokSys code is a generic modeling and simulation environment developed in GA. Its RZIP model treats the plasma as a fixed spatial distribution of currents which couple with the surrounding conductors through circuit equations. Both codes have been individually used for the VDE study on many tokamak devices, such as JT-60U, EAST, NSTX, DIII-D, and ITER. Considering the model differences, benchmark work is needed to answer whether they reproduce each other＇s results correctly. In this paper, the TSC and TokSys codes are used for analyzing the CFETR vertical instability passive and active controls design simultaneously. It is shown that with the same inputs, the results from these two codes conform with each other.展开更多
Single event upsets(SEUs) induced by heavy ions were observed in 65 nm SRAMs to quantitatively evaluate the applicability and effectiveness of single-bit error correcting code(ECC) utilizing Hamming Code.The results s...Single event upsets(SEUs) induced by heavy ions were observed in 65 nm SRAMs to quantitatively evaluate the applicability and effectiveness of single-bit error correcting code(ECC) utilizing Hamming Code.The results show that the ECC did improve the performance dramatically,with the SEU cross sections of SRAMs with ECC being at the order of 10^(-11) cm^2/bit,two orders of magnitude higher than that without ECC(at the order of 10^(-9) cm^2/bit).Also,ineffectiveness of ECC module,including 1-,2- and 3-bits errors in single word(not Multiple Bit Upsets),was detected.The ECC modules in SRAMs utilizing(12,8) Hamming code would lose work when 2-bits upset accumulates in one codeword.Finally,the probabilities of failure modes involving 1-,2- and 3-bits errors,were calcaulated at 39.39%,37.88%and 22.73%,respectively,which agree well with the experimental results.展开更多
胚胎电子细胞的基因循环存储模块在辐射空间容易受到单粒子翻转(SEU)影响,由于缺乏有效的自检手段,严重制约了胚胎电子阵列在深空等辐射环境中的应用。本文设计了一种新型的具有SEU自修复能力的触发器单元,并结合汉明纠错码,设计了一种...胚胎电子细胞的基因循环存储模块在辐射空间容易受到单粒子翻转(SEU)影响,由于缺乏有效的自检手段,严重制约了胚胎电子阵列在深空等辐射环境中的应用。本文设计了一种新型的具有SEU自修复能力的触发器单元,并结合汉明纠错码,设计了一种新型的具有SEU自检和自修复能力的基因循环存储模块,可以在维持胚胎电子细胞阵列正常工作的情况下,实时有效的检测并修复1 bit SEU。以2 bit进位加法器为例,通过仿真实验,验证了胚胎电子细胞的SEU自检和自修复能力。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11305216,11305209,and 11375191)the National Magnetic Confinement Fusion Research Program of China(Grant Nos.2014GB103000 and 2014GB110003)External Cooperation Program of BIC,Chinese Academy of Sciences(Grant No.GJHZ201303)
文摘Vertical displacement event（VDE） is a big challenge to the existing tokamak equipment and that being designed. As a Chinese next-step tokamak, the Chinese Fusion Engineering Test Reactor（CFETR） has to pay attention to the VDE study with full-fledged numerical codes during its conceptual design. The tokamak simulation code（TSC） is a free boundary time-dependent axisymmetric tokamak simulation code developed in PPPL, which advances the MHD equations describing the evolution of the plasma in a rectangular domain. The electromagnetic interactions between the surrounding conductor circuits and the plasma are solved self-consistently. The TokSys code is a generic modeling and simulation environment developed in GA. Its RZIP model treats the plasma as a fixed spatial distribution of currents which couple with the surrounding conductors through circuit equations. Both codes have been individually used for the VDE study on many tokamak devices, such as JT-60U, EAST, NSTX, DIII-D, and ITER. Considering the model differences, benchmark work is needed to answer whether they reproduce each other＇s results correctly. In this paper, the TSC and TokSys codes are used for analyzing the CFETR vertical instability passive and active controls design simultaneously. It is shown that with the same inputs, the results from these two codes conform with each other.
基金Supported by the National Natural Science Foundation of China(Nos.11079045 and 11179003)the Important Direction Project of the CAS Knowledge Innovation Program(No.KJCX2-YW-N27)
文摘Single event upsets(SEUs) induced by heavy ions were observed in 65 nm SRAMs to quantitatively evaluate the applicability and effectiveness of single-bit error correcting code(ECC) utilizing Hamming Code.The results show that the ECC did improve the performance dramatically,with the SEU cross sections of SRAMs with ECC being at the order of 10^(-11) cm^2/bit,two orders of magnitude higher than that without ECC(at the order of 10^(-9) cm^2/bit).Also,ineffectiveness of ECC module,including 1-,2- and 3-bits errors in single word(not Multiple Bit Upsets),was detected.The ECC modules in SRAMs utilizing(12,8) Hamming code would lose work when 2-bits upset accumulates in one codeword.Finally,the probabilities of failure modes involving 1-,2- and 3-bits errors,were calcaulated at 39.39%,37.88%and 22.73%,respectively,which agree well with the experimental results.
文摘胚胎电子细胞的基因循环存储模块在辐射空间容易受到单粒子翻转(SEU)影响,由于缺乏有效的自检手段,严重制约了胚胎电子阵列在深空等辐射环境中的应用。本文设计了一种新型的具有SEU自修复能力的触发器单元,并结合汉明纠错码,设计了一种新型的具有SEU自检和自修复能力的基因循环存储模块,可以在维持胚胎电子细胞阵列正常工作的情况下,实时有效的检测并修复1 bit SEU。以2 bit进位加法器为例,通过仿真实验,验证了胚胎电子细胞的SEU自检和自修复能力。
