硅微条探测器热控制系统(Tracker thermo control system,TTCS)是阿尔法磁谱仪(Alpha magnetic spectrometer,AMS)内一个重要的子系统.其主要任务是将AMS-02内部硅微条探测器产生的热量传导到辐射板以排散到太空,并维持探测器内部温度...硅微条探测器热控制系统(Tracker thermo control system,TTCS)是阿尔法磁谱仪(Alpha magnetic spectrometer,AMS)内一个重要的子系统.其主要任务是将AMS-02内部硅微条探测器产生的热量传导到辐射板以排散到太空,并维持探测器内部温度高度稳定。为提高可靠性,TTCS运行过程监控采取了结合自保护机制的分层监控实现策略.首先介绍了TTCS系统总体架构及组成;在此基础上着重描述了TTCS监控硬件平台,并分析了分层监控策略的模型结构和功能分配,硬件实现的自保护机制(Health-guard)进一步提高了系统运行安全度,最后结合地面模拟测试平台,给出了系统运行测试结果.该监控策略已成功应用在TTCS原型件设计中.展开更多
Soil gas radon 222Rn concentration was measured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were...Soil gas radon 222Rn concentration was measured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were taken for soil gas measurements, staring from the ground surface. The results suggested that the largest concentration was 340 ± 22 Bq/m3 for 60cm depth at in Al-Tarfia point sample P3, and the smallest concentration was 26 ± 5 Bq/m3 for surface 0 cm depth at El-Bakria, point sample P5. The results obtained from this study indicate that the region has background radioactivity levels within the natural limits.展开更多
In this study, the natural radionuclides in soil and sand have been measured by using high purity germanium (HPGe) detector. While, radon exhalation rate has been measured by Alpha GUARD. The data analysis is performe...In this study, the natural radionuclides in soil and sand have been measured by using high purity germanium (HPGe) detector. While, radon exhalation rate has been measured by Alpha GUARD. The data analysis is performed to determine 226Ra, 232Th, and 40K activity concentrations in addition to 222Rn exhalation rate. The values of radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), and absorbed dose rate were ranged from 46.46 to 124.16 Bq⋅kg−1, 0.07 to 0.33 Bq⋅kg−1, 0.09 to 0.42 Bq⋅kg−1, and 13.24 to 58.37 nGy⋅h−1 respectively in all samples. The area and mass exhalation rates were increased from 9.16 ±2.83 to 16.18 ±2.83 Bq⋅m−2⋅h−1 and 1.8 ±1.34 to 11.35 ±0.98 Bq⋅kg−1⋅h−1 respectively.展开更多
文摘硅微条探测器热控制系统(Tracker thermo control system,TTCS)是阿尔法磁谱仪(Alpha magnetic spectrometer,AMS)内一个重要的子系统.其主要任务是将AMS-02内部硅微条探测器产生的热量传导到辐射板以排散到太空,并维持探测器内部温度高度稳定。为提高可靠性,TTCS运行过程监控采取了结合自保护机制的分层监控实现策略.首先介绍了TTCS系统总体架构及组成;在此基础上着重描述了TTCS监控硬件平台,并分析了分层监控策略的模型结构和功能分配,硬件实现的自保护机制(Health-guard)进一步提高了系统运行安全度,最后结合地面模拟测试平台,给出了系统运行测试结果.该监控策略已成功应用在TTCS原型件设计中.
文摘Soil gas radon 222Rn concentration was measured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were taken for soil gas measurements, staring from the ground surface. The results suggested that the largest concentration was 340 ± 22 Bq/m3 for 60cm depth at in Al-Tarfia point sample P3, and the smallest concentration was 26 ± 5 Bq/m3 for surface 0 cm depth at El-Bakria, point sample P5. The results obtained from this study indicate that the region has background radioactivity levels within the natural limits.
文摘In this study, the natural radionuclides in soil and sand have been measured by using high purity germanium (HPGe) detector. While, radon exhalation rate has been measured by Alpha GUARD. The data analysis is performed to determine 226Ra, 232Th, and 40K activity concentrations in addition to 222Rn exhalation rate. The values of radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), and absorbed dose rate were ranged from 46.46 to 124.16 Bq⋅kg−1, 0.07 to 0.33 Bq⋅kg−1, 0.09 to 0.42 Bq⋅kg−1, and 13.24 to 58.37 nGy⋅h−1 respectively in all samples. The area and mass exhalation rates were increased from 9.16 ±2.83 to 16.18 ±2.83 Bq⋅m−2⋅h−1 and 1.8 ±1.34 to 11.35 ±0.98 Bq⋅kg−1⋅h−1 respectively.
