分类： 物理学 >> 核物理学 提交时间： 2024-03-09
Xin-Tong Du
Xiao-Bao Wei
Shao-Bo Ma
Li-Na Sheng
Xue-Heng Zhang
Shi-Tao Wang
Kai-Long Wang
Chun-Wang Ma
Hool-Jin Ong
Zhi-Yu Sun
Shu-Wen Tang
Yu-Hong Yu
摘要： The study of nuclide production and its properties in the N=126 neutron-rich region is the frontier and hot topic in nuclear physics and astrophysics research. The upcoming High energy FRagment Separator (HFRS) at the High Intensity heavy-ion Accelerator Facility (HIAF), an in-flight separator at relativistic energies, is characterized by high beam intensity, large ion-optical acceptance, high magnetic rigidity, and high momentum resolution power. It provides an opportunity for the study of the production and properties of neutron-rich nuclei around N=126. In this paper, an experimental scheme is proposed to produce the neutron-rich nuclei around N=126 and simultaneously measure their mass and lifetime based on the HFRS separator, and the feasibility of this scheme is evaluated by the simulations. The results show that under the high resolution optical mode many new neutron-rich nuclei approaching the r-process abundance peak around A=195 can be produced for the first time, and many nuclei with unknown mass and lifetime can be produced with high statistics. Using the time-of-flight corrected by the measured dispersive position and the energy loss information, the cocktails produced from the 208Pb fragmentation can be unambiguously identified. Moreover, the masses of some neutron-rich nuclei in the vicinity of N=126 can be measured with high precision using the time-of-flight magnetic rigidity technique. This indicates that the HIAF-HFRS facility has potential for the production and property research of neutron-rich nuclei around N=126, which is of great significance for expanding chart of nuclides, developing nuclear theories, and understanding the origin of heavy elements in the universe.
分类： 核科学技术 >> 核科学与技术 提交时间： 2023-11-06
Yang, Mingyu
Qian, Yi
Pu, Tianlei
Lu, Weijian
Sun, Zhikun
Zhao, Hongyun
Zhang, Jiarui
Liu, Zhengqiang
摘要： HFRS (HIAF FRagment separator (HFRS) will be the radioactive secondary beam separation line on High-Intensity heavy-ion Accelerator Facility (HIAF) in China. Several TPC detectors, with high count rates, are planned for particle identification and beam monitoring at HFRS. This paper presents an event-driven internal memory and synchronous readout (EDIMS) prototype ASIC chip. The aim is to provide HFRS-TPC with high-precision time and charge measurements with high count rates and a large dynamic range. The first prototype EDIMS chip integrated 16 channels and is fabricated using a 0.18-um CMOS process. Each channel consists of a charge-sensitive amplifier, fast shaper, slow shaper, peak detect-and-hold circuit, discriminator with time-walk compensation, analog memory, and FIFO. The token ring is used for clock-synchronous readout. The chip is taped and tested.
分类： 物理学 >> 核物理学 提交时间： 2023-09-11
摘要： 本工作制作了一套由快发光塑料闪烁体耦合快光电倍增管组成的塑料闪烁体飞行时间探测器的样机，通过皮秒脉冲激光测试了探测器的时间性能，旨在为将来的 HIAF-HFRS 飞行时间探测器作预研。对于两种不同尺寸的塑闪探测器，通过改变激光的光斑大小、频率、光强和位置等各项参数来模拟真实束流的情况，并使用 CAEN-DT5742 数字化仪以及 Mesytec-MCFD16+MTDC32 电子学系统进行了系统的测试。使用聚焦激光照射在塑闪中心位置时，小尺寸 (7 cm7 cm) 塑闪探测器的 ToF 分辨最好可达 8 ps；小-大 (26 cm10 cm) 塑闪探测器的 TOF 分辨最好可达到 12 ps。在改变激光各项参数后，得到的响应时间分辨为 1016 ps 和 1946 ps。测试结果表明，所得到的 ToF 分辨满足 HFRS 束线的时间分辨性能要求，为飞行时间探测器的优化奠定了基础。
分类： 物理学 >> 核物理学 分类： 核科学技术 >> 核探测技术与核电子学 提交时间： 2024-02-27
摘要： 正在建设中的强流重离子加速器装置 HIAF 配备了一条先进的放射性束流线 HFRS，建成后将为中国 高能放射性核束物理研究提供新的机遇。HFRS 的特点是流强极高 (初级束流强度 1 × 1011 ppp)，这对用于粒 子鉴别的能损探测器提出了非常高的计数率要求。传统的能损探测器对信号处理一般依次采用电荷灵敏前放、 主放、ADC 的技术路线。该方案存在电子学响应速度较慢、灵活性较差、难以处理高计数率下信号堆积严重 等问题。我们对此提出一种新的适用于高计数率的能损探测器方案：以耐辐照的多次取样电离室为能损探测 器，优化结构和读出方式提高探测器响应速度，使用快电荷灵敏前放对能损探测器信号初步放大后、直接用 波形数字化仪采集波形再进行后续数字算法处理。并利用放射源和束流对该方案进行了验证测试。利用 3 组 分 𝛼 源测试时，对采集的波形使用数字成形算法处理，能量分辨率（FWHM）可达 1.31%。在 RIBLL2 提供 300 MeV/u 的 56Fe 束流测试中，采用时间常数 𝜏f = 2 𝜇𝑠 的快电荷灵敏前放在计数率接近 1 MHz 时仍未发生明显堆积。
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