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Anisotropic deformation of Au nanoparticles by highly charged ion Xe21+ irradiation
No full text<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">We present a detailed study of the deformation of Au nanoparticles (NPs) caused by the irradiation of highly charged ions (HCIs). When spherical Au NPs with a diameter of 19.8 nm were irradiated by 1 MeV Xe21+ ions with a fluence of 2 x 10(14) cm(-2), their anisotropic deformation was observed by atomic force microscopy. The results show that spherical Au NPs expand perpendicular to the ion beam changing their shape to oblate ellipsoidal. The size aspect ratio (major over minor axis) of the observed deformed Au NPs is about 1.23. The deformation process is described by a viscoelastic thermal spike model. The HCI beam deformation technique provides a unique method to tailor the shape of noble metal NPs.</span
Test of IMME in fp shell via direct mass measurements of TZ = -3/2 nuclides
No full text<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">Isochronous mass spectrometry has been applied to neutron-deficient Ni-58 projectile fragments at the HIRFL-CSR facility in Lanzhou, China. Masses of four short-lived T-z = -3/2 nuclides Ti-41, Cr-45, Fe-49, and Ni-53 have been measured with a precision of 20 - 40 keV. The new mass data enabled for the first time to test the isobaric multiplet mass equation (IMME) in fp-shell nuclei. We observed that the IMME is inconsistent with the generally accepted quadratic form for the A = 53, T = 3/2 quartet. We performed full space shell model calculations and compared them with the new experimental results. The main results were published in Y.H. Zhang et al., Physical Review Letters 109 (2012). Here we give details on the experiment and data analysis as well as summarize the main findings.</span
A study of highly charged ions interacting with a plasma target at the Institute of Modern Physics
No full text<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">A new experimental area for the investigation of ion beam matter interaction and ion beam plasma interaction was completed at the Institute of Modern Physics (Lanzhou, China). We report the details of this low-energy setup and first results on ion beam matter interaction, where we measured the charge state of O5+ ions at 1 MeV passing through a hydrogen gas target. The data were compared with the Monte-Carlo simulation results for cold hydrogen gas and hydrogen plasma.</span
Observation of superheavy nuclide 271Ds based on the gas-filled separator at IMP
No full text<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">A gas-filled recoil separator was designed and built newly at Institute of Modern Physics (IMP) in Lanzhou. With the recent commissioning of the separator, the decay properties of (271)Ds were studied via the Pb-208 (Ni-64, n) reaction at a beam energy of 313.3 MeV. One alpha-decay chain for (271)Ds was established in total. The experimental result is consistent with the values reported in the literature.</span
Kr L X-ray and Au M X-ray emission for 1.5 MeV - 3.9 MeV Kr13+ ions impacting on an Au target
No full text<span style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;">Kr L X-ray and Au M X-ray emission for Kr</span><sup style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;">13+</sup><span style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;"> ions with energies of 1.5 MeV and 3.9 MeV impacting on an Au target are investigated at heavy ion research facility in Lanzhou (HIRFL). The L-shell X-ray yield per ion of Kr is measured as a function of incident energy. In addition, Kr L X-ray production cross section is extracted from the yield and compared with the result obtained from the classical binary-encounter approximation (BEA) model. Furthermore, the intensity ratio of the Au M</span><inf style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;">β3</inf><span style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;"> to M</span><inf style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;">α1</inf><span style="color: rgb(0, 0, 0); font-family: Arial, verdana, helvetica, sans-serif; line-height: 14px;"> X-ray is investigated as a function of incident energy. © 2013 Chinese Physical Society and IOP Publishing Ltd.(26 refs)</span
重离子诱变酵母培养基的优化与研究
No full text<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">利用~(12)C~(6+)离子诱变技术对面包酵母菌种进行诱变,得到一株粗蛋白含量达到55%以上的菌株,借助Minitab16.0,采用Plackett-Burman实验设计法及响应面分析法,对诱变后面包酵母菌发酵培养基的成分进行了优化,得到3个最为显著的主要影响因子:葡萄糖、酵母抽提物和硫酸镁。利用最陡爬坡实验逼近最大响应区域后,利用Box-Behnken实验设计及响应面分析法进行回归分析。通过求解回归方程,得到优化发酵的条件为,葡萄糖:11.03 g/L、酵母抽提物:6.53 g/L、硫酸镁:5.59 g/L。面包酵母生物量为4.84 g/L,相比未进行优化时的生物量提高了15%。</span><span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">A mutant bread yeast strain with high protein content of 55% was gained by use of ~(12)C~(6+) ions. The MINITAB 16.0 software, Plackett-Burman experimental design and response surface methodology were applied to optimize the culture medium for the irradiated yeast. The most important three factors which influenced the culture results were identified as glucose, magnesium sulphate and yeast extract. The path of the steepest ascent was undertaken to approach the optimal region of the three significant factors. Box-Behnken design and response surface methodology were used for the regression analysis. Finally, the optimal fermentation conditions were identified as glucose 11.03 g/L, yeast extract 6.53 g/L and magnesium sulphate 5.59 g/L by the regression analysis. It was found that the biomass of the bread yeasts reached 4.84 g/L and increased by 15% compared to original conditions.</span
强流ECR离子源引出系统研究
No full text<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">为了提高强流ECR离子源的引出束流品质,分别设计了1#和2#引出系统,利用束流引出模拟软件PBGUNS对1#和2#引出系统进行了质子束流引出与传输的模拟计算,结合实际测得的发射度数据分析引出系统,发现2#引出系统比1#引出系统引出束流品质高。对ECR离子源引出系统的电势等位线分布等参数引起的球差进行了简单数学推导及MATLAB绘图,并结合1#和2#引出系统束流相图模拟结果证明了球差会使引出束流品质有效发射度增长,通过适当加大电极孔径可改善束流聚焦情况,得到了束流光学聚焦较好的束流引出系统设计。</span><span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">To improve the quality of extracted ion beam from a high current ECR ion source, 1# and 2# extraction systems were designed and tested. The PBGUNS code was used to simulate the 1# and 2# extraction systems of proton ion beam. The emittance measurement results with the two different extraction systems were compared and analyzed with the simulation, the conclusion that more high quality beam extracted from 2# system than 1# system was got. The formula derivation of ECR ion source extraction system spherical aberration and MATLAB drawing was done by the analyzing on the distribution of extraction field equipotentials, effective emittance increasing caused by spherical aberration was proved by 1# and 2# extraction systems beam phase space simulation result, beam focusing would be improved if electrode hole size increasing appropriately and a general concept on good optics focusing of ion beam extraction system was proposed finally.</span
用于加速器驱动次临界核能系统的固体散裂靶
No full text<span style="color: rgb(69, 69, 69); font-family: Arial, Helvetica, sans-serif; line-height: 21px; text-indent: 24px;"> 本实用新型涉及一种用于加速器驱动次临界核能系统的固体散裂靶，属于核能技术领域。一种用于加速器驱动次临界核能系统的固体散裂靶，其主要特点在于：包括有在质子束流通道的内腔端头设有靶体，在靶体上设有多排冷却通孔，在多排冷却通孔的一端设有氦气入口联箱，氦气入口联箱与氦气入口联箱连接管连接；在另一端设有冷却氦气出口联箱，氦气出口联箱与氦气出口联箱连接管连接。本实用新型的优点是固体散裂靶结构容易加工制造，由于采用同一种材料，焊接比较容易，结构满足ADS系统对散裂靶提出的其他功能方面的要求。</span
End-to-end simulation of the C-ADS Injector II with a 3-D field map
No full textThe Injector II, one of the two parallel injectors of the high-current superconducting proton driver linac for the China Accelerator-Driven System (C-ADS) project, is being designed and constructed by the Institute of Modern Physics. At present, the design work for the injector is almost finished. End-to-end simulation has been carried out using the TRACK multiparticle simulation code to check the match between each acceleration section and the performance of the injector as a whole. Moreover, multiparticle simulations with all kinds of errors and misalignments have been performed to define the requirements of each device. The simulation results indicate that the lattice design is robust. In this paper, the results of end-to-end simulation and error simulation with a 3-D field map are presented