Commissioning of electron cooling in CSRm

A new generation electron cooler has started operation in the heavy ion synchrotron CSRm which is used to increase the intensity of heavy ions. Transverse cooling of the ion beam after horizontal multi-turn injection allows beam accumulation at the injection energy. After optimization of the accumulation process an intensity increase in a synchrotron pulse by more than one order of magnitude has been achieved. In given accumulation time interval of 10 seconds, 108 particles have been accumulated and accelerated to the final energy. The momentum spread after accumulation and acceleration in the 10-4 range has been demonstrated in six species of ion beams. Primary measurements of accumulation process varying with electron energy, electron beam current, electron beam profile, expansion factor and injection interval have been performed. The lifetimes of ion beams in the presence of electron beams were roughly measured with the help of DCCT signal.     

HIRFL-CSR commissioning in 2006 and 2007

HIRFL-CSR, a new heavy ion cooler-storage-ring system at IMP, had been in commissioning since the beginning of 2006. In the two years of 2006 and 2007 the CSR commissioning was finished, including the stripping injection (STI), electron-cooling with hollow electron beam, C-beam stacking with the combination of STI and e-cooling, the wide energy-range synchrotron ramping from 7 MeV/u to 1000 MeV/u by changing the RF harmonic-number at mid-energy, the multiple multi-turn injection (MMI), the beam accumulation with MMI and e-cooling for heavy-ion beams of Ar, Kr and Xe, the fast extraction from CSRm and single-turn injection to CSRe, beam stacking in CSRe and the RIBs mass-spectrometer test with the isochronous mode in CSRe by using the time-of-flight method.     

高平均功率调Q准连续Nd:YAG激光器

通过选用低掺杂浓度的Nd:YAG晶体棒、热近非稳腔优化设计、双棒串接热致双折射补偿技术以及双Q开关正交放置结构，在LD抽运功率1116W时，实现调Q准连续全固态Nd:YAG激光器1064nm输出，平均功率达258W，光束质量M²～15.5，重复频率为10kHz，脉冲宽度为64ns，峰值功率达0.4GW，光光转换效率达23.1%. 关键词： Nd:YAG激光器 准连续波 激光二极管抽运 固体激光器     

逆流式回流冷凝管的研制与测试

研制了一种逆流式回流冷凝管。分别以乙醚、乙醇、蒸馏水、环己醇、乙二醇作为工作流体，以自来水作为冷却剂，测试其热交换效率。与目前通用的并流式冷凝管比较，逆流式回流冷凝管具有热交换效率高、节水、被冷却流体损失少、乳胶管不易老化等优点。     

分形与非线性科学

当自然科学刚从神学中解放出来时,可以说是大量地继承了古希腊哲学家的思想和方法。伽利略,作为近代自然科学奠基者,第一次为自然科学创立了两个法则,观察实验和量化方法。伽利略用他自己制造的望远镜观察太阳系的运行,在铁塔高处向人们演示两个铁球同     

四极透镜的三阶像差分析

用Lie代数方法推导了四极透镜的三阶像差.像差源于四极透镜场在轴向的有限分布.在一阶焦距不变的条件下,增加透镜的长度或增加透镜的孔径可以减小三阶像差     

High-power output from a compact OPCPA laser system

With a tabletop hybrid Nd:YAG-Nd:glass laser as pump source, a compact optical parametric chirpedpulse amplification(OPCPA)laser system with a peak output power of 16.7 TW and a pulse duration of120 fs has been demonstrated.Chirped pulses are amplified from 50 pJ to more than 3.1 J with an energygain of above 6×10~(10)by three LBO optical parametric amplifiers with a pump energy of 12.4 J at 532nm.After compression, a final output of 2.0-J/120-fs pulse is obtained. To the best of our knowledge,itis the highest peak output power from an OPCPA laser so far.In addition, a practical design of 1-PWlaser system based on the technique of OPCPA is also proposed.     

核能的和平利用及前景

 全面禁止核试验条约的谈判,由于印度拒绝签字而陷入僵局。经过新闻传媒的宣传,“核”又触发了人们的敏感神经。一时间使“核”问题成为了人们关注的焦点。各界舆论众说纷云,使人们对核能的和平利用产生了众多的质疑。     

两个基于苯并咪唑还原席夫碱的双核铜(Ⅱ)配合物的合成、晶体结构和电化学性质

在甲醇体系中,分别将苯并咪唑还原席夫碱HL与四氟硼酸铜和硝酸铜进行配位反应得到2个结构类似的双核铜配合物[CuL(CH_3OH)]_2(BF_4)_2(1)和[CuL(NO_3)_2]_2(2)(HL=2-(((2-(2-benzimidazyl) ethyl)aimino)methyl)phenol),并用元素分析、红外光谱、紫外-可见光谱和单晶X射线衍射对其结构进行了表征。结构分析表明:2个配合物均属于单斜晶系,P2_1/c空间群,为酚氧桥联的双核铜结构,其中每个Cu(Ⅱ)处于N_2O_3的畸变四方锥构型。配合物中的氢键将配合物1和配合物2分别连接成一维和三维网络结构。采用循环伏安法测定了双核配合物的氧化还原电位,表明2个配合物均显示2个准可逆单电子还原过程。