液体闪烁体(简称“液闪”)探测器因其成本效益高而被广泛应用于中微子探测。液闪探测器利用带电粒子激发的闪烁光来测量粒子的相关信息,并通过粒子径迹推断其运动方向。对于能量较低导致径迹过短的粒子,液闪探测器探测到的闪烁光子数量...液体闪烁体(简称“液闪”)探测器因其成本效益高而被广泛应用于中微子探测。液闪探测器利用带电粒子激发的闪烁光来测量粒子的相关信息,并通过粒子径迹推断其运动方向。对于能量较低导致径迹过短的粒子,液闪探测器探测到的闪烁光子数量远超切伦科夫光子数量(约高出两到三个数量级),因此利用切伦科夫光确定粒子运动方向极为困难,相关研究多集中于低光产额的液闪实验。对于高光产额的液闪实验,如Borexino、KamLAND和江门中微子实验(JUNO),在这方面的研究较少,尤其是在深度学习的应用方面。因此,探究深度学习在此领域的潜力具有重要意义。本工作开发了一种基于卷积神经网络(Convolutional Neural Network,CNN)的深度学习模型CRCP(Cherenkov Ring Center Predictor)用于液闪探测器点粒子运动方向重建,并与基于拟合的方法进行了效果对比。研究表明深度学习算法具有较好的重建方向能力。本工作可用于江门中微子实验、萨德伯里中微子观测站(SNO+)实验和慢液闪方案的锦屏中微子实验,以提高探测器对太阳中微子相关的本底的压低能力。展开更多
微结构探测器是目前国际上气体探测器研究的热点,但普通微结构探测器的性能无法满足核保障等研究领域对能量分辨的要求。为此团队自主研制了一种高能量分辨MicroMegas探测器。通过建立测试系统对探测器进行测试,发现其性能不仅取决于探...微结构探测器是目前国际上气体探测器研究的热点,但普通微结构探测器的性能无法满足核保障等研究领域对能量分辨的要求。为此团队自主研制了一种高能量分辨MicroMegas探测器。通过建立测试系统对探测器进行测试,发现其性能不仅取决于探测器本身的制作工艺,还与系统的使用及测试方法紧密相关。为充分发挥探测器性能,需要对气体探测器性能影响的各方面因素进行测试与分析,建立数据库,优化测试系统和实验条件。在上述研究基础上,利用^(55)Fe放射源在Ar+5%iC_4H_(10)的气体下对原子能院制作的MicroMegas进行能量分辨测试,在5.9 ke V能量下获得能量分辨的平均值为11.7%,与目前国际上微结构探测器的最好水平持平。通过优化测试系统和实验条件,能够获得更加稳定的探测器性能,更容易在核保障、核物理与辐射探测领域推广。展开更多
The article contains an error regarding the electron spectra displayed in Figs.4 and 5 and the data extracted from these spectra.The measurements were made with the SESAME magnetic spectrometer,the working principle o...The article contains an error regarding the electron spectra displayed in Figs.4 and 5 and the data extracted from these spectra.The measurements were made with the SESAME magnetic spectrometer,the working principle of which is recalled in Fig.1.Specifically,a magnetic dipole is used to separate charged particles(electrons in the case of this experiment)depending on their energy,charge and mass.The deflected particles then hit an imaging plate(IP)and deposit energy in its sensitive layer.The kinetic energy of the particles can be evaluated from their impact position on the IP and their number can be inferred from the local energy deposition.展开更多
Recently H_(2)^(+)ion beam finds widespread use in many fields,and the demand of high-current H_(2)^(+)ion sources is urgent for numerous applications.However,there are currently almost no reported ion sources capable...Recently H_(2)^(+)ion beam finds widespread use in many fields,and the demand of high-current H_(2)^(+)ion sources is urgent for numerous applications.However,there are currently almost no reported ion sources capable of generating a directcurrent(DC)H_(2)^(+)beam with tens of mA current.In previous work at Peking University(PKU),H_(2)^(+)ion beams with a current of over 40 mA have been obtained in pulse mode,and a current of 16 mA was achieved in DC mode.In this paper,we report the generation of a DC H_(2)^(+)ion beam with a current of 22 mA extracted from an improved miniaturized microwave driven ion source(MMDIS).Beam analysis shows that the H_(2)^(+)fraction in the extracted beam is about 70%.The emittance of the mixed hydrogen beam is about 0.12π·mm·mrad.These results provide references for the applications of H_(2)^(+)beam and the design of H_(2)^(+)ion source.展开更多
文摘液体闪烁体(简称“液闪”)探测器因其成本效益高而被广泛应用于中微子探测。液闪探测器利用带电粒子激发的闪烁光来测量粒子的相关信息,并通过粒子径迹推断其运动方向。对于能量较低导致径迹过短的粒子,液闪探测器探测到的闪烁光子数量远超切伦科夫光子数量(约高出两到三个数量级),因此利用切伦科夫光确定粒子运动方向极为困难,相关研究多集中于低光产额的液闪实验。对于高光产额的液闪实验,如Borexino、KamLAND和江门中微子实验(JUNO),在这方面的研究较少,尤其是在深度学习的应用方面。因此,探究深度学习在此领域的潜力具有重要意义。本工作开发了一种基于卷积神经网络(Convolutional Neural Network,CNN)的深度学习模型CRCP(Cherenkov Ring Center Predictor)用于液闪探测器点粒子运动方向重建,并与基于拟合的方法进行了效果对比。研究表明深度学习算法具有较好的重建方向能力。本工作可用于江门中微子实验、萨德伯里中微子观测站(SNO+)实验和慢液闪方案的锦屏中微子实验,以提高探测器对太阳中微子相关的本底的压低能力。
文摘微结构探测器是目前国际上气体探测器研究的热点,但普通微结构探测器的性能无法满足核保障等研究领域对能量分辨的要求。为此团队自主研制了一种高能量分辨MicroMegas探测器。通过建立测试系统对探测器进行测试,发现其性能不仅取决于探测器本身的制作工艺,还与系统的使用及测试方法紧密相关。为充分发挥探测器性能,需要对气体探测器性能影响的各方面因素进行测试与分析,建立数据库,优化测试系统和实验条件。在上述研究基础上,利用^(55)Fe放射源在Ar+5%iC_4H_(10)的气体下对原子能院制作的MicroMegas进行能量分辨测试,在5.9 ke V能量下获得能量分辨的平均值为11.7%,与目前国际上微结构探测器的最好水平持平。通过优化测试系统和实验条件,能够获得更加稳定的探测器性能,更容易在核保障、核物理与辐射探测领域推广。
文摘The article contains an error regarding the electron spectra displayed in Figs.4 and 5 and the data extracted from these spectra.The measurements were made with the SESAME magnetic spectrometer,the working principle of which is recalled in Fig.1.Specifically,a magnetic dipole is used to separate charged particles(electrons in the case of this experiment)depending on their energy,charge and mass.The deflected particles then hit an imaging plate(IP)and deposit energy in its sensitive layer.The kinetic energy of the particles can be evaluated from their impact position on the IP and their number can be inferred from the local energy deposition.
基金supported by the National Natural Science Foundation of China(Grant No.11975036)support from the State Key Laboratory of Nuclear Physics and Technology at PKU.
文摘Recently H_(2)^(+)ion beam finds widespread use in many fields,and the demand of high-current H_(2)^(+)ion sources is urgent for numerous applications.However,there are currently almost no reported ion sources capable of generating a directcurrent(DC)H_(2)^(+)beam with tens of mA current.In previous work at Peking University(PKU),H_(2)^(+)ion beams with a current of over 40 mA have been obtained in pulse mode,and a current of 16 mA was achieved in DC mode.In this paper,we report the generation of a DC H_(2)^(+)ion beam with a current of 22 mA extracted from an improved miniaturized microwave driven ion source(MMDIS).Beam analysis shows that the H_(2)^(+)fraction in the extracted beam is about 70%.The emittance of the mixed hydrogen beam is about 0.12π·mm·mrad.These results provide references for the applications of H_(2)^(+)beam and the design of H_(2)^(+)ion source.
