Charge-changing cross section(σcc)measurements via the transmission method have recently seen significant progress with the aim of determining the charge radii of exotic nuclei.In this work,we report a newσcc measur...Charge-changing cross section(σcc)measurements via the transmission method have recently seen significant progress with the aim of determining the charge radii of exotic nuclei.In this work,we report a newσcc measurement of 304(9)MeV/nucleon^(28)Si on carbon at the second Radioactive Ion Beam Line in Lanzhou(RIBLL2)and describe the data analysis procedure in detail.This procedure is essential for evaluating the systematic uncertainty in the transmission method.The determinedσcc of 1125(11)mb is found to be consistent with the existing data at similar energies.The present work will serve as a reference forσcc determinations at RIBLL2.展开更多
太阳极轨射电望远镜(SPORT)是一颗从事太阳活动研究的卫星。重离子探测仪是其中的高能粒子探测仪的关键组成部分。鉴于重离子探测仪对多种类离子(2≤Z≤26)的鉴别和大范围能段(8～300 Me V/u)的测量需求,中国科学院近代物理研究所设计...太阳极轨射电望远镜(SPORT)是一颗从事太阳活动研究的卫星。重离子探测仪是其中的高能粒子探测仪的关键组成部分。鉴于重离子探测仪对多种类离子(2≤Z≤26)的鉴别和大范围能段(8～300 Me V/u)的测量需求,中国科学院近代物理研究所设计并研制了一套Si-Cs I(Tl)望远镜探测系统样机,这套望远镜系统由1个Si探测器、1个入射面为正六边形的CsI(Tl)晶体及其专用电子学系统构成。利用兰州重离子加速器冷却储存环系统(HIRFL-CSR)提供的高品质束流对这套望远镜探测系统样机进行了在束测试,完成了种类为2≤Z≤18的重离子直接测量与鉴别,利用直接测量的重离子,进行外推得到,最高测量要求的300MeV/u Fe离子也在设计要求的范围内。实验结果显示这套望远镜探测器样机满足空间中对大范围能段重离子探测的设计需求,该套方案为SPORT计划中的重离子探测仪的设计及建造奠定了很好的技术基础。展开更多
Plastic scintillation detectors for Time-of-Flight（TOF） measurements are almost essential for event-byevent identification of relativistic rare isotopes. In this work, a pair of plastic scintillation detectors of di...Plastic scintillation detectors for Time-of-Flight（TOF） measurements are almost essential for event-byevent identification of relativistic rare isotopes. In this work, a pair of plastic scintillation detectors of dimensions50×50×3^t mm^3and 80×100×3^t mm^3have been set up at the External Target Facility（ETF）, Institute of Modern Physics（IMP）. Their time, energy and position responses are measured with the^（18）O primary beam at 400 Me V/nucleon. After off-line corrections for walk effect and position, the time resolutions of the two detectors are determined to be 27 ps（σ） and 36 ps（σ）, respectively. Both detectors have nearly the same energy resolution of3.1%（σ） and position resolution of about 3.4 mm（σ）. The detectors have been used successfully in nuclear reaction cross section measurements, and will be be employed for upgrading the RIBLL2 beam line at IMP as well as for the high energy branch at HIAF.展开更多
A knockout reaction induced by ^6He at 61.2 MeV/u was carried out at the HIRFL-RIBLL ra- dioactive beam line. The α core fragments at forward angles were detected in coincidence with the recoiled protons at large ang...A knockout reaction induced by ^6He at 61.2 MeV/u was carried out at the HIRFL-RIBLL ra- dioactive beam line. The α core fragments at forward angles were detected in coincidence with the recoiled protons at large angles. From this coincident measurement the valence nucleon knockout mechanism and the core knockout mechanism can be separated according to the polar angle correlation between the core fragments and the recoiled protons. It is demonstrated that, when reconstructing the resonant state of a weakly bound nucleus, the contamination resulting from the core knockout mechanism should be eliminated in order to obtain the correct structure information.展开更多
文摘描述了为兰州重离子加速器冷却储存环(HIRFL-CSR)外靶实验系统硅微条阵列探测器而设计的前端电子学模块。该模块采用专用ASIC芯片,可以处理96路能量信号。对前端电子学模块的性能进行了测试,结果表明,该模块在0.1～0.7 V范围内的积分非线性好于0.3%;其电子学分辨好于0.45%,最大串扰小于10%;通道一致性测试结果好于1.3%;在室温下连续工作24 h后,零点峰位最大漂移为1.48 m V。
基金Supported by the National Natural Science Foundation of China(U1832211,11961141004,11922501,11475014,11905260)the Western Light Project of Chinese Academy of Sciencesthe Natural Science Foundation of Anhui Province,China(2008085MA17)。
文摘Charge-changing cross section(σcc)measurements via the transmission method have recently seen significant progress with the aim of determining the charge radii of exotic nuclei.In this work,we report a newσcc measurement of 304(9)MeV/nucleon^(28)Si on carbon at the second Radioactive Ion Beam Line in Lanzhou(RIBLL2)and describe the data analysis procedure in detail.This procedure is essential for evaluating the systematic uncertainty in the transmission method.The determinedσcc of 1125(11)mb is found to be consistent with the existing data at similar energies.The present work will serve as a reference forσcc determinations at RIBLL2.
文摘太阳极轨射电望远镜(SPORT)是一颗从事太阳活动研究的卫星。重离子探测仪是其中的高能粒子探测仪的关键组成部分。鉴于重离子探测仪对多种类离子(2≤Z≤26)的鉴别和大范围能段(8～300 Me V/u)的测量需求,中国科学院近代物理研究所设计并研制了一套Si-Cs I(Tl)望远镜探测系统样机,这套望远镜系统由1个Si探测器、1个入射面为正六边形的CsI(Tl)晶体及其专用电子学系统构成。利用兰州重离子加速器冷却储存环系统(HIRFL-CSR)提供的高品质束流对这套望远镜探测系统样机进行了在束测试,完成了种类为2≤Z≤18的重离子直接测量与鉴别,利用直接测量的重离子,进行外推得到,最高测量要求的300MeV/u Fe离子也在设计要求的范围内。实验结果显示这套望远镜探测器样机满足空间中对大范围能段重离子探测的设计需求,该套方案为SPORT计划中的重离子探测仪的设计及建造奠定了很好的技术基础。
基金Supported by National Natural Science Foundation of China(11475014,11235002)National Key Research and Development Program(2016YFA0400500)
文摘Plastic scintillation detectors for Time-of-Flight（TOF） measurements are almost essential for event-byevent identification of relativistic rare isotopes. In this work, a pair of plastic scintillation detectors of dimensions50×50×3^t mm^3and 80×100×3^t mm^3have been set up at the External Target Facility（ETF）, Institute of Modern Physics（IMP）. Their time, energy and position responses are measured with the^（18）O primary beam at 400 Me V/nucleon. After off-line corrections for walk effect and position, the time resolutions of the two detectors are determined to be 27 ps（σ） and 36 ps（σ）, respectively. Both detectors have nearly the same energy resolution of3.1%（σ） and position resolution of about 3.4 mm（σ）. The detectors have been used successfully in nuclear reaction cross section measurements, and will be be employed for upgrading the RIBLL2 beam line at IMP as well as for the high energy branch at HIAF.
基金Supported by National Basic Research Program (973 Program) of China (2007CB815002)National Natural ScienceFoundation of China (11035001,10775003,10827505,J0730316)
文摘A knockout reaction induced by ^6He at 61.2 MeV/u was carried out at the HIRFL-RIBLL ra- dioactive beam line. The α core fragments at forward angles were detected in coincidence with the recoiled protons at large angles. From this coincident measurement the valence nucleon knockout mechanism and the core knockout mechanism can be separated according to the polar angle correlation between the core fragments and the recoiled protons. It is demonstrated that, when reconstructing the resonant state of a weakly bound nucleus, the contamination resulting from the core knockout mechanism should be eliminated in order to obtain the correct structure information.
