对特殊核材料等进行无损检测时,快中子探测器的时间分辨率对系统的成像时间和图像质量等方面具有重要影响。提高时间分辨率的主要困难在于无法精准测量入射中子与物质相互作用深度(depth of interaction,DOI)。为了减小DOI效应对快中子...对特殊核材料等进行无损检测时,快中子探测器的时间分辨率对系统的成像时间和图像质量等方面具有重要影响。提高时间分辨率的主要困难在于无法精准测量入射中子与物质相互作用深度(depth of interaction,DOI)。为了减小DOI效应对快中子探测的影响,利用Geant4模拟软件构建了基于塑料闪烁体的双端读出快中子探测器模型,系统地研究了闪烁体厚度对探测器时间分辨率性能的影响。在此基础上,提出了平均两端定时和重建中子作用点2种提高时间分辨率的方法。研究结果表明,这2种校准方法均能降低DOI测量不准确对快中子探测产生的影响,提高快中子探测器的时间分辨率。对于厚度为100 mm的闪烁体探测器,利用重建中子作用点法对光电倍增管(photomultiplier tube,PMT)定时补偿后,探测器的时间分辨率由(1030±5)ps提高到(612±2)ps。展开更多
The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive positi...The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.展开更多
The ohmic contact interface between diamond and metal is essential for the application of diamond detectors.Surface modification can significantly affect the contact performance and eliminate the interface polarizatio...The ohmic contact interface between diamond and metal is essential for the application of diamond detectors.Surface modification can significantly affect the contact performance and eliminate the interface polarization effect.However,the radiation stability of a diamond detector is also sensitive to surface modification.In this work,the influence of surface modification technology on a diamond ohmic contact under high-energy radiation was investigated.Before radiation,the specific contact resistivities(ρc)between Ti/Pt/Au-hydrogen-terminated diamond(H-diamond)and Ti/Pt/Au-oxygenterminated diamond(O-diamond)were 2.0×10^(-4)W·cm^(2) and 4.3×10^(-3)Wcm^(2),respectively.After 10 MeV electron radiation,the ρc of Ti/Pt/Au H-diamond and Ti/Pt/Au O-diamond were 5.3×10^(-3)W·cm^(2)and 9.1×10^(-3)W·cm^(2),respectively.The rates of change of ρc of H-diamond and O-diamond after radiation were 2550%and 112%,respectively.The electron radiation promotes bond reconstruction of the diamond surface,resulting in an increase in ρc.展开更多
文摘对特殊核材料等进行无损检测时,快中子探测器的时间分辨率对系统的成像时间和图像质量等方面具有重要影响。提高时间分辨率的主要困难在于无法精准测量入射中子与物质相互作用深度(depth of interaction,DOI)。为了减小DOI效应对快中子探测的影响,利用Geant4模拟软件构建了基于塑料闪烁体的双端读出快中子探测器模型,系统地研究了闪烁体厚度对探测器时间分辨率性能的影响。在此基础上,提出了平均两端定时和重建中子作用点2种提高时间分辨率的方法。研究结果表明,这2种校准方法均能降低DOI测量不准确对快中子探测产生的影响,提高快中子探测器的时间分辨率。对于厚度为100 mm的闪烁体探测器,利用重建中子作用点法对光电倍增管(photomultiplier tube,PMT)定时补偿后,探测器的时间分辨率由(1030±5)ps提高到(612±2)ps。
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61574171,61704127,11875229,51872251,and 12027813)。
文摘The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB3608601).
文摘The ohmic contact interface between diamond and metal is essential for the application of diamond detectors.Surface modification can significantly affect the contact performance and eliminate the interface polarization effect.However,the radiation stability of a diamond detector is also sensitive to surface modification.In this work,the influence of surface modification technology on a diamond ohmic contact under high-energy radiation was investigated.Before radiation,the specific contact resistivities(ρc)between Ti/Pt/Au-hydrogen-terminated diamond(H-diamond)and Ti/Pt/Au-oxygenterminated diamond(O-diamond)were 2.0×10^(-4)W·cm^(2) and 4.3×10^(-3)Wcm^(2),respectively.After 10 MeV electron radiation,the ρc of Ti/Pt/Au H-diamond and Ti/Pt/Au O-diamond were 5.3×10^(-3)W·cm^(2)and 9.1×10^(-3)W·cm^(2),respectively.The rates of change of ρc of H-diamond and O-diamond after radiation were 2550%and 112%,respectively.The electron radiation promotes bond reconstruction of the diamond surface,resulting in an increase in ρc.
