利用快中子脉冲堆(Chinese Fast Burst ReactorⅡ,CFBR-Ⅱ)产生的快中子,采用枯草芽孢杆菌黑色变种为材料,考查了中子辐射灭菌效果及剂量、剂量率、辐照温度、照射状态等辐射灭菌影响因素。结果表明,在剂量率为7.4Gy/min时的D10值为384....利用快中子脉冲堆(Chinese Fast Burst ReactorⅡ,CFBR-Ⅱ)产生的快中子,采用枯草芽孢杆菌黑色变种为材料,考查了中子辐射灭菌效果及剂量、剂量率、辐照温度、照射状态等辐射灭菌影响因素。结果表明,在剂量率为7.4Gy/min时的D10值为384.6Gy,中子剂量与存活芽孢对数满足y=-0.0026x+10.462的函数关系;在剂量为800Gy时,剂量率与存活芽孢对数满足y=7.7414X-0.0834的函数关系;升高温度有利于中子辐射灭菌;中子辐照不同状态芽孢,其存活率为:菌片>粉末>液体。展开更多
针对核电站内高放射性、高湿热、强腐蚀的恶劣物化环境,设计制作了一种新型耐高温环氧树脂基中子屏蔽复合材料。该材料以AFG90-H环氧树脂为基体,在42 k Gy辐照环境下,其玻璃化转变温度可达262oC,弯曲强度仅下降1.63%,中子屏蔽性能明显...针对核电站内高放射性、高湿热、强腐蚀的恶劣物化环境,设计制作了一种新型耐高温环氧树脂基中子屏蔽复合材料。该材料以AFG90-H环氧树脂为基体,在42 k Gy辐照环境下,其玻璃化转变温度可达262oC,弯曲强度仅下降1.63%,中子屏蔽性能明显优于常见高密度聚乙烯(High density polyethylene,HDPE)、石蜡、6002环氧树脂(Epoxy resin,EP)等材料。加入B4C颗粒后,材料中子屏蔽性能和耐高温力学性能得到显著提升,且耐酸碱腐蚀性能保持不变。综合实验表明,该复合材料具有耐高温、耐辐射、耐酸碱腐蚀等优点,且密度小,适合作为移动式探测设备中子屏蔽防护层使用。展开更多
介绍了一种抗辐射加固型低压差线性稳压器(LDO)的电路设计,内部集成了精密基准源、误差放大器、输出调整管和上电复位时间控制等模块电路。重点介绍了采用总剂量、中子效应的器件参数变化预估方法进行仿真验证。芯片采用0.6μm Bi CMOS...介绍了一种抗辐射加固型低压差线性稳压器(LDO)的电路设计,内部集成了精密基准源、误差放大器、输出调整管和上电复位时间控制等模块电路。重点介绍了采用总剂量、中子效应的器件参数变化预估方法进行仿真验证。芯片采用0.6μm Bi CMOS工艺制造,测试验证结果表明,产品在满足使用要求的同时,具备抗电离总剂量3×10~3 Gy(Si)、抗中子注量0.6×10^(14) n·cm^(-2)的性能,适用于核辐射环境。辐射测试结果证明了设计的正确性。展开更多
Neutron radiation experiments of optocouplers at back-streaming white neutrons(back-n)in China Spallation Neutron Source(CSNS)are presented.The displacement damages induced by neutron radiation are analyzed.The perfor...Neutron radiation experiments of optocouplers at back-streaming white neutrons(back-n)in China Spallation Neutron Source(CSNS)are presented.The displacement damages induced by neutron radiation are analyzed.The performance degradations of two types of optocouplers are compared.The degradations of current transfer ratio(CTR)are analyzed,and the mechanisms induced by radiation are also demonstrated.With the increase of the accumulated fluence,the CTR is degrading linearly with neutron fluence.The radiation hardening of optocouplers can be improved when the forward current is increased.Other parameters related to CTR degradation of optocouplers are also analyzed.展开更多
Carbon ions have significant advantages in tumor therapy because of their physical and biological prop- erties. In view of the radiation protection, the safety of patients is the most important issue in therapy proces...Carbon ions have significant advantages in tumor therapy because of their physical and biological prop- erties. In view of the radiation protection, the safety of patients is the most important issue in therapy processes. Therefore, the effects of the secondary particles produced by the carbon ions in the tumor therapy should be carefully considered, especially for the neutrons. In the present work, the neutron radiation field induced by carbon ions was evaluated by using the FLUKA code. The simulated results of neutron energy spectra and neutron dose was found to be in good agreement with the experiment data. In addition, energy deposition of carbon ions and neutrons in tissue-like media was studied, it is found that the secondary neutron energy deposition is not expected to exceed 1% of the carbon ion energy deposition in a typical treatment.展开更多
文摘利用快中子脉冲堆(Chinese Fast Burst ReactorⅡ,CFBR-Ⅱ)产生的快中子,采用枯草芽孢杆菌黑色变种为材料,考查了中子辐射灭菌效果及剂量、剂量率、辐照温度、照射状态等辐射灭菌影响因素。结果表明,在剂量率为7.4Gy/min时的D10值为384.6Gy,中子剂量与存活芽孢对数满足y=-0.0026x+10.462的函数关系;在剂量为800Gy时,剂量率与存活芽孢对数满足y=7.7414X-0.0834的函数关系;升高温度有利于中子辐射灭菌;中子辐照不同状态芽孢,其存活率为:菌片>粉末>液体。
文摘针对核电站内高放射性、高湿热、强腐蚀的恶劣物化环境,设计制作了一种新型耐高温环氧树脂基中子屏蔽复合材料。该材料以AFG90-H环氧树脂为基体,在42 k Gy辐照环境下,其玻璃化转变温度可达262oC,弯曲强度仅下降1.63%,中子屏蔽性能明显优于常见高密度聚乙烯(High density polyethylene,HDPE)、石蜡、6002环氧树脂(Epoxy resin,EP)等材料。加入B4C颗粒后,材料中子屏蔽性能和耐高温力学性能得到显著提升,且耐酸碱腐蚀性能保持不变。综合实验表明,该复合材料具有耐高温、耐辐射、耐酸碱腐蚀等优点,且密度小,适合作为移动式探测设备中子屏蔽防护层使用。
文摘介绍了一种抗辐射加固型低压差线性稳压器(LDO)的电路设计,内部集成了精密基准源、误差放大器、输出调整管和上电复位时间控制等模块电路。重点介绍了采用总剂量、中子效应的器件参数变化预估方法进行仿真验证。芯片采用0.6μm Bi CMOS工艺制造,测试验证结果表明,产品在满足使用要求的同时,具备抗电离总剂量3×10~3 Gy(Si)、抗中子注量0.6×10^(14) n·cm^(-2)的性能,适用于核辐射环境。辐射测试结果证明了设计的正确性。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11875223,11805155,and 11690043)the Chinese Academy of Sciences Strategic Pilot Science and Technology Project(Grant No.XDA15015000)+1 种基金the Innovation Foundation of Radiation Application,China(Grant No.KFZC2018040201)the Foundation of State Key Laboratory of China(Grant Nos.SKLIPR1803 and 1903Z)
文摘Neutron radiation experiments of optocouplers at back-streaming white neutrons(back-n)in China Spallation Neutron Source(CSNS)are presented.The displacement damages induced by neutron radiation are analyzed.The performance degradations of two types of optocouplers are compared.The degradations of current transfer ratio(CTR)are analyzed,and the mechanisms induced by radiation are also demonstrated.With the increase of the accumulated fluence,the CTR is degrading linearly with neutron fluence.The radiation hardening of optocouplers can be improved when the forward current is increased.Other parameters related to CTR degradation of optocouplers are also analyzed.
文摘Carbon ions have significant advantages in tumor therapy because of their physical and biological prop- erties. In view of the radiation protection, the safety of patients is the most important issue in therapy processes. Therefore, the effects of the secondary particles produced by the carbon ions in the tumor therapy should be carefully considered, especially for the neutrons. In the present work, the neutron radiation field induced by carbon ions was evaluated by using the FLUKA code. The simulated results of neutron energy spectra and neutron dose was found to be in good agreement with the experiment data. In addition, energy deposition of carbon ions and neutrons in tissue-like media was studied, it is found that the secondary neutron energy deposition is not expected to exceed 1% of the carbon ion energy deposition in a typical treatment.
