CCD探测器的相对探测效率标定

探测器的探测效率是表征探测器性能的一个重要参数,需对其进行标定。本次试验使用复旦大学EBIT设备,以其配有的高纯锗探测器为标准,对低能X射线望远镜的CCD探测器进行探测效率的相对标定,得到在6.7、8.3、9.1、9.7、10.4、11.9和13.3 keV七个能量点CCD探测器相对于高纯锗探测器的探测效率。其讨论使用的标定方法对今后的探测效率标定工作具有意义。     

~(238)Pu低能光子源衰变γ能谱识别

利用同轴P型高纯锗探测器,对X荧光分析的~(238)Pu低能光子源进行γ能谱分析,并对~(233)Pa、~(224)Ra、~(212)Pb、~(212)Bi及~(208)Tl的特征γ射线进行分析,确定上述核素的来源。其中,~(233)Pa是生产~(238)Pu的原料237 Np的衰变产物,~(224)Ra、~(212)Pb、~(212)Bi及~(208)Tl均为生产~(238)Pu的副产物~(236)Pu的衰变子核。能量为350、440、844、1 014、1 130、1 266、1 368、1 454keV的γ射线是α粒子轰击源封装材料引起原子核库伦激发或γ射线照射周边环境引起核激发产生。进行效率刻度后,使用γ能谱法计算各放射性核素的活度,并根据放射性平衡计算各放射性核素的质量。通过对~(238)Pu源γ能谱的分析,建立计算放射性同位素活度与质量的方法。     

放射源152Eu的能谱识别及和峰特性分析

使用低本底高纯锗（HPGe）探测器测量放射源¹⁵²Eu的γ能谱，识别能谱中出现的所有峰，分辨出干扰峰，并对和峰的特性进行分析，结合计数率随距离变化曲线以及通过分辨率比较和峰与特征峰的差异，为和峰的辨别提供判据。在和峰效应引起的全能峰计数率减少的情况下，修正各全能峰计数率，计算放射源中¹⁵²Eu杂质含量，结果显示，与修正前差异较明显，表明在能谱分析尤其是考查全能峰强度数据时，需要进行符合相加修正。     

Magnetic Dipole Band in 113In

High spin states in the odd-A nucleus 113In have been investigated using the re-action 110Pd(7Li,4n) at a beam energy of 50 MeV. A new positive parity dipole band with the configuration of π(g9/2)-1ν(h11/2)2ν(g7/2)2 is established. The effective interaction V(θ) values of this band have been successfully described by a semiclassical geometric model based on shear mechanism, which show that the dipole band has the characteristics of magnetic rotation. In addition the collective rotational angular momentum for this band is extracted. The results show that the core contribution increases gradually with the increase of the rotation frequency.     

Yrast Band in 122I and Band Termination

High spin states of the odd-odd nucleus 122 I have been investigated via the fusion-evaporation reaction 116 Cd(11B, 5n) at a beam energy of 68 MeV. The yrast band is extended up to Iπ=(29+). The band termination at Iπ=(22+) reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface (TRS) calculations. In addition, the Iπ=(29+) state is assigned to the [πh11/2(πg7/2)2]23/2-[(νh11/2)3(νd5/2)2]35/2-configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.     

High-k Structures in (124)～Cs

High spin states in the odd-odd nucleus 124 Cs have been investigated through the fusion-evaporation reaction 116 Sn(11 B,3n) 124 Cs with a beam energy of 45 MeV.A new rotational band is established and assigned as the high-k configuration of πg 9/2 [404]9/2 +νh 11/2 [523]7/2.Some structures linking to this band have also been observed.According to the results of the excitation energy systematics,the lowest level of this band is assigned as 9,and the 8 isomer bandhead has not been observed.Another isomer with a half life of 6.3 s has also been observed with its new decay paths established.Its excitation energy is raised by 79 keV,but its I π is not changed.     

放射源~(152)Eu的能谱识别及和峰特性分析

使用低本底高纯锗(HPGe)探测器测量放射源~(152)Eu的γ能谱,识别能谱中出现的所有峰,分辨出干扰峰,并对和峰的特性进行分析,结合计数率随距离变化曲线以及通过分辨率比较和峰与特征峰的差异,为和峰的辨别提供判据。在和峰效应引起的全能峰计数率减少的情况下,修正各全能峰计数率,计算放射源中~(154)Eu杂质含量,结果显示,与修正前差异较明显,表明在能谱分析尤其是考查全能峰强度数据时,需要进行符合相加修正。