高电离态原子光谱测量

简要介绍了兰州重离子加速器上的高电离态原子光谱实验测量和取得的部分实验结果.The excitation spectra and level lifetimes of highly charged atoms for heavier elements of Ne, S and Ar have been measured by using the beam foil method on the heavy ion accelerator in Lanzhou. Emission spectra in the wavelength region of 25-400  was studied. On the whole, the agreement between our experimental results and other experiments is fairly good.     

类铍硫n=2的某些能级寿命的实验研究

主要报导用束箔技术对天体等离子体中重要元素硫的高电离态原子n =2的某些能级寿命的实验测量.实验数据用CANDY程序分析 ,并与理论计算结果和其它的实验结果作了比较. Lifetime measurement has been carried out for some low lying n=2 levels in the four electron ions S ⅩIII by using the beam-foil technique at National Laboratory of Heavy Ion Accelerator, Lanzhoiu, China. Spectra of highly ionized sulfur obtained at an energy of 2.5 MeV/nucleon have been studied in the 190-530  wavelength range. Experimental decay curves are analysized by the CANDY program, and compared with theoretical calculations and experimental measureaments.     

Implementation and verification of different ECC mitigation designs for BRAMs in flash-based FPGAs

Embedded RAM blocks(BRAMs) in field programmable gate arrays(FPGAs) are susceptible to single event effects(SEEs) induced by environmental factors such as cosmic rays, heavy ions, alpha particles and so on. As technology scales, the issue will be more serious. In order to tackle this issue, two different error correcting codes(ECCs), the shortened Hamming codes and shortened BCH codes, are investigated in this paper. The concrete design methods of the codes are presented. Also, the codes are both implemented in flash-based FPGAs. Finally, the synthesis report and simulation results are presented in the paper. Moreover, heavy-ion experiments are performed,and the experimental results indicate that the error cross-section of the device using the shortened Hamming codes can be reduced by two orders of magnitude compared with the device without mitigation, and no errors are discovered in the experiments for the device using the shortened BCH codes.     

高离化态镍的光谱

在中国原子能研究院串列加速器上利用束箔技术研究了120-400 ? 镍的高离化态镍光谱.验Ni XIII to XX研究中得到的谱线大多数属于Ni XIII 到 XX的跃迁,18条谱线是测量到的.     

Angular dependence of multiple-bit upset response in static random access memories under heavy ion irradiation

Experimental evidence is presented relevant to the angular dependences of multiple-bit upset (MBU) rates and patterns in static random access memories (SRAMs) under heavy ion irradiation. The single event upset (SEU) cross sections under tilted ion strikes are overestimated by 23.9% 84.6%, compared with under normally incident ion with the equivalent linear energy transfer (LET) value of ～ 41 MeV/(mg/cm 2 ), which can be partially explained by the fact that the MBU rate for tilted ions of 30 is 8.5%-9.8% higher than for normally incident ions. While at a lower LET of ～ 9.5 MeV/(mg/cm 2 ), no clear discrepancy is observed. Moreover, since the ion trajectories at normal and tilted incidences are different, the predominant double-bit upset (DBU) patterns measured are different in both conditions. Those differences depend on the LET values of heavy ions and devices under test. Thus, effective LET method should be used carefully in ground-based testing of single event effects (SEE) sensitivity, especially in MBU-sensitive devices.     

Development of front-end readout electronics for silicon strip detectors

Front-end readout electronics have been developed for silicon strip detectors at our institute. In this system an Application Specific Integrated Circuit (ASIC) ATHED is used to realize multi-channel energy and time measurements. The slow control of ASIC chips is achieved by parallel port and the timing control signals of ASIC chips are implemented with the CPLD. The data acquisition is carried out with a PXI-DAQ card. The software has a user-friendly GUI developed with LabWindows/CVI in the Windows XP operating system. The test results show that the energy resolution is about 1.14% for alpha at 5.48 MeV and the maximum channel crosstalk of the system is 4.60%. The performance of the system is very reliable and is suitable for nuclear physics experiments.     

用于粒子探测器的CMOS FET采样保持电路的设计与仿真(英文)

介绍了一个峰保持电路。该电路适用于silicon strip,Si(Li),CdZn Te and CsI等探测器,实现采样-保持功能。已成功进行了基于CMOSFET的采样-保持电路的设计和仿真,通过使用Proteus的PSPICE仿真器和BSIMV3.3模型参数完成了电路性能的仿真。同时,实现了采样时间可在60ns到4.44s范围内进行选择,该电路具有较好的线性。     

谱仪放大器参数对脉冲形状分析法鉴别轻带电粒子的影响

我们利用脉冲形状分析法,通过CsI(T1)闪烁体加光二极管读出探测器对~(12)C(46.7MeV/u)+~(58)Ni反应中出射的轻带电粒子进行了鉴别。实验中发现放大器成形时间常数的选取对轻带电粒子鉴别的结果有明显影响。本文基于信号转移函数的Laplace变换方法,对这个问题进行了计算和分析,成功地解释了所遇到的实验现象。     

天体等离子体中铝发射谱线的研究

结合天体等离子体中铝发射谱和某些能级寿命的测量,对束箔光谱技术可为天体物理学研究提供重要信息和重要性进行了简述     

谱仪放大器参数对脉冲形状分析法鉴别轻带电粒子的影响

我们利用脉冲形状分析法,通过CsI(T1)闪烁体加光二极管读出探测器对¹²C(46.7/MeV/u)+⁵⁸Ni反应中出射的轻带电粒子进行了鉴别.实验中发现放大器成形时间常数的选取对轻带电粒子鉴别的结果有明显影响.本文基于信号转移函数的Laplace变换方法,对这个问题进行了计算和分析,成功地解释了所遇到的实验现象.