• Digital coincidence acquisition applied to portable β liquid scintillation counting device

    分类: 核科学技术 >> 核探测技术与核电子学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》

    摘要: A digital coincidence acquisition system applied to a portable liquid scintillation counting device is developed. The system which simplifies the device design consists of a digitizer card of Agilent U1066A DC438, a discriminator and a host computer. The anode analog pulses from two photomultiplier tubes are captured by the system, which adopts the sequence acquisition storage mode. By choosing proper threshold for each channel, coincidence time window of 30 ns, and comparing the pulse amplitudes from two channels, the portable scintillation counting device can be used to detect particles. For the unquenched standard 3H sample, the results show that the detection efficiency is (58.50.1)% and the background is (86.70.7) cpm. Meanwhile, 3H spectrum is obtained.

  • Simulation of a soft-gamma-ray polarimeter on board a microsatellite

    分类: 物理学 >> 核物理学 提交时间: 2023-09-11

    摘要: Gamma-ray polarimetry is a new and prospective tool for studying various extreme high-energy celestial objects and is of great significance for the development of astrophysics. With the rapid development of microsatellite technology, the advantages in space exploration are becoming increasingly apparent. Therefore, in this paper, we conducted a simulation study on a soft gamma-ray polarimeter for a microsatellite in space. Here, we proposed a unique design structure for the polarimeter based on the microsatellite design concept and the Compton scattering principle. And then, the detailed Monte Carlo simulations using mono-energetic gamma-ray linear polarization sources and the Crab-like sources in the energy range of 0.1-10 MeV with full consideration of the orbital background were performed. The simulation results show that the polarimeter can exhibit excellent polarization detection performance. The modulation factor is 0.800.01, and the polarization angles are accurate within an error of 0.2 at 200 keV for on-axis incidence. For the Crab-like sources for on-axis incidence, the polarization degrees are consistent with the set values within the error tolerance, the modulation factor is 0.760.01, and the minimum detectable polarization reaches 2.4% at 3 for an observation time of 106 seconds. In addition, the polarimeter has recoil electron tracking, imaging, and powerful background suppression at a large field of view (2 sr). The polarimeter designed can meet the requirements of a space-soft gamma-ray polarization detector very well and has a bright research prospect.