This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we ...This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils （Au, Sc, Ti, Ni, and plates） which have been irradiated in the central position of the reactor core （setting number 203） at a reactor power level （64.57±2.91 watts）. The activation foils were counted by solid-state detector HPGe （high pure germanium detector） （gamma spectrometry）. The experimental data of nuclear reaction rates （saturated activity per target nucleus） and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP （spectrum analysis neutron detection code-version Budapest University） code： a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, （2.41 ± 0.01） × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in （3.85 ± 0.14） × 10^9 n·cm^-2·s^-1 for neutron flux, （1.09 ±0.02） × 10^9n·cm^-2·s^-1 for intermediate neutron flux and （3.41 ± 0.02） × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.展开更多
Time reversal mirror （TRM） can use the physical characteristics of the underwater acoustic （UWA） channel to focus on the desired user in multi-user UWA communication. The active average sound intensity （AASI） de...Time reversal mirror （TRM） can use the physical characteristics of the underwater acoustic （UWA） channel to focus on the desired user in multi-user UWA communication. The active average sound intensity （AASI） detector can estimate all azimuths of users with the same frequency band at the same time in order to achieve directional communication by vector combination. Space-division multiple access （SDMA） based on TRM combined with the AASI detector is proposed in this paper, which can make the capacity of the code division multiple access （CDMA） UWA system significantly increase. The simulation and lake test results show that the 7-user UWA multi-user system can achieve low bit error communication.展开更多
文摘This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils （Au, Sc, Ti, Ni, and plates） which have been irradiated in the central position of the reactor core （setting number 203） at a reactor power level （64.57±2.91 watts）. The activation foils were counted by solid-state detector HPGe （high pure germanium detector） （gamma spectrometry）. The experimental data of nuclear reaction rates （saturated activity per target nucleus） and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP （spectrum analysis neutron detection code-version Budapest University） code： a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, （2.41 ± 0.01） × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in （3.85 ± 0.14） × 10^9 n·cm^-2·s^-1 for neutron flux, （1.09 ±0.02） × 10^9n·cm^-2·s^-1 for intermediate neutron flux and （3.41 ± 0.02） × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.
基金supported by the National Natural Science Foundation of China(6147113751179034)+3 种基金the Ships Pre-research Support Technology Fund(13J3.1.5)the Natural Science Foundation of Heilongjiang Province(F201109)the Innovation Talents of Science and the Technology Research Projects of Harbin(2013RFQXJ101)the National Defense Basic Technology Research(JSJC2013604C012)
文摘Time reversal mirror （TRM） can use the physical characteristics of the underwater acoustic （UWA） channel to focus on the desired user in multi-user UWA communication. The active average sound intensity （AASI） detector can estimate all azimuths of users with the same frequency band at the same time in order to achieve directional communication by vector combination. Space-division multiple access （SDMA） based on TRM combined with the AASI detector is proposed in this paper, which can make the capacity of the code division multiple access （CDMA） UWA system significantly increase. The simulation and lake test results show that the 7-user UWA multi-user system can achieve low bit error communication.
