964 resultados para FRS-ESR FACILITY


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介绍了Super-FRS超导二极磁铁的磁场优化和端部削斜方案,采用OPERA软件对活极头进行削斜计算,得出合理的活极头尺寸,使各场下的积分均匀度在要求范围内达到了±2×10-4。最后将计算的积分场均匀度与磁场测量的结果进行比较,结果吻合得较好,验证了这种端部活极头优化计算方法的正确性。

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Some superconducting magnets research at IMP (Institute of Modern Physics, CAS, Lanzhou) will be described in this paper. Firstly, a superconducting electron cyclotron resonance ion source (SECRAL) was successfully built to produce intense beams of highly charged heavy ions for Heavy Ion Research Facility in Lanzhou (HIRFL). An innovation design of SECRAL is that the three axial solenoid coils are located inside of a sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. Some excellent results of ion beam intensity have been produced and SECRAL has been put into operation to provide highly charged ion beams for HIRFL since May 2007. Secondly, a super-ferric dipole prototype of FAIR Super-FRS is being built by FCG (FAIR China Group) in cooperation with GSI. Its superconducting coils and cryostat is made and tested in the Institute of Plasma Physics (IPP, Hefei), and it more 50 tons laminated yoke was made in IMP. This super-ferric dipole static magnetic field was measured in IMP, it reach to the design requirement, ramping field and other tests will be done in the future. Thirdly, a 3 T superconducting homogenous magnetic field solenoid with a 70 mm warm bore has been developed to calibrate Hall sensor, some testing results is reported. And a penning trap system called LPT (Lanzhou Penning Trap) is now being developed for precise mass measurements.

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The FAIR China Group (FCG), consisting of the Institute of Modern Physics (IMP Lanzhou), the Institute of Plasma Physics (ASIPP, Hefei) and the Institute of Electric Engineering (IEE, Beijing) developed and manufactured in cooperation with GSI, Germany a prototype of a superferric dipole for the Super-Fragment-Separator of the FAIR-project [1]. The dipole magnets of the separator will have a deflection radius of 12.5 m, a field up to 1.6 T, a gap of at least 170 mm and an effective length of more than 2 meters to bend ion beams with a rigidity from 2 T . m up to 20 T . m. The magnets operate at DC mode. These requirements led to a superferric design with a yoke weight of more than 50 tons and a maximum stored energy of more than 400 kJ. The principles of yoke, coil and cryostat construction will be presented. We will also show first results of tests and measurements realized at ASIPP and at IMP.

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中国签订了为德国FAIR国际大科学工程加工SUPER-FRS/CR超导二极磁铁样机的合作备忘录。该超导二极磁铁属于常温铁芯、低温线圈的超导磁铁,该磁铁的磁场强度0.15~1.6T,偏转角度15°,偏转半径8125mm,磁场精度要求±1×10-4,磁铁总重量约50吨。磁铁铁芯采用0.5mm的硅钢片叠压成型,由中科院近代物理研究(IMP)所计算、设计制造,线圈采用4.2K液氦浸泡式超导线圈,由合肥等离子体所设计制造(IPP)。 超导磁体的力学性能分析一直是超导磁体的基础问题。本文利用有限元分析方法,借助有限分析工具ANSYS、ADINA、OPERA等,分析了超导磁体的电磁场,着重模拟计算了SUPER-FRS/CR超导二极磁铁的电磁力作用;模拟了降温过程,计算了杜瓦、线圈热应力的作用;并对SUPER-FRS/CR超导线圈进行地震载荷作用的模拟。对以上不同的受力作用所遵循的不同的机械设计准则,进行不同的分析,最后计算结果证明设计的结构是安全、可靠的。由于超导线圈的结构复杂,导致在线圈拐角的地方应力有些集中,但是并不影响结构的可靠性。 本文还介绍了超导实验线圈的一些工艺设计,例如超导线圈的绕制,低温材料的选择,电流引线的设计工艺,以及VPI工艺。并对实验磁体进行了一系列的低温性能测试,例如短样测试、降温实验等,获得了一些重要的低温实验参数。这些参数将为以后超导磁体的研制提供宝贵的依据

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本文工作分为两个部分:第一部分是设计德国重离子研究中心(GSI)的一段新的次级束流线;第二部分计算了在建的R工已LLZ对裂变反应碎片的传输分离,同时为提高分离本领对RIBLLZ进行了优化计算和设计。FRS是德国重离子研究中心(GSI)的次级束流线。其分支FRS-CAVEB的终端是川JAD工N的实验终端,这条线的束流品质不理想(传输率只有0.1%),因此GSI拟将AI'AD州设备(原在CAVEB)移到CAVEC中,形成FRS一CAVEC束流线,又称FRS-R3Bcave。本文对FRS-CoveC进行了束流光学设计和计算,同时模拟了FRS-CAVEC对弹核碎裂反应的传输分离。新束线按计算结果安装了一个二极磁铁和3个四极磁铁,并通过了实验测试,测试结果表明:(1)系统具有良好的消色散特性,即系统在FRS出口和实验终端处达到了消色差。(2)系统的传输率基本符合理论计算值,相对CAVEB分支传输率提高了一个量级以上。当不放任何阻止物质在束流线上时,Ar主束传输率可以达到100%;当放置3mm厚的Sdntillator探测器在S2,S8,CaveC处时,主束传输率基本和理论计算值相近(640k-计算值,610k-实验值)。对比FRS-C八VEB的实验传输率(0.1%),可知通过改进,FRS-C八VEC的传输率将得到极大的改善。RIBLLZ是连接CSR两环之间的次级束流线。现有的RIBLLZ束流线设计的比较紧凑,立体角接收度大,使得所有粒子都可通过系统,可以作为零度质谱仪,尤其是可以将裂变产生的奇异核素注入到实验环进行质量测量。本文模拟了弹核碎片和裂变反应产生的次级束在现有的RIBLLZ上的传输情况。计算表明,现有的RIBLLZ对通过u裂变产生的大量较重奇异核素,具有很高的传输率。另一方面,现有的RIB七LZ在散焦面只有两个四极磁铁,为达到系统的消色差及较大的分辨率会使得Y方向的束流控制困难。基于此,对现有的R咸喝锻蓄尔\一些改进计算。还理论计算比较了两个系统对裂变反应的传输分离情况。玺认算试知飞(1)优化后的RIBLLZ系统对束流在Y方向的控制将更灵活。(2)对裂变反应产物的传输,除了作为零度质谱仪外还可以作为单一核素的分离器。(3浑税盯确集磁系统的传输率对降能器厚度敏感度降低,对于u裂变反应产生的132sn的传输率,当降能器厚度从19/cmZ变化到39/clnu时,传输率下降20%,而未优化的RIBLLZ系统的传输率将下降90%。

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报道了电子自旋磁共振谱仪与IBMPC微型机联用,建立了所需要的硬件系统,包括接口和放大器,研制了分辨率为12位的AD/DA转换器,达到同步采样控制,并实现了X-Y记录仪,示波器,绘图仪与打印机的输出,同时系统软件配有信号采样、信号累加、信号平滑、谱线加减、测量g因子及A值,ESR谱的一、二次积分等一系列数据处理程序,还具有谱线模拟、线形分析等一些应用软件,对于谱的定量和解析极为方便,大大提高了谱仪的功能.

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Two types of macromolecular free radicals similar to CH2CONH(C) over dotHCH(2) similar to (a) and similar to CH2(C) over dot = O (b) trapped in irradiated polyamide-1010 (PA1010) and PA1010 filled with neodymium oxide (Nd2O3) were characterized by an ESR approach. It is found that (a) is prevailingly trapped in the fold surface of the lamellae and (b) in the amorphous phase. This result suggests that trapped radicals mainly exist in the non-crystalline phases. The effect of the fold surface area of the lamellae on the behavior of the trapped radicals is discussed in this paper. Whether for the specimens with similar crystallinities, but different crystallite sizes, or for those with the same concentration of neodymium oxide, but different crystallinities, radical (a) exists dominantly in the specimen with a larger fold surface area of the lamellae. Under certain circumstances, radical (a) can transform into radical (b), obviously for a specimen with a larger fold surface area of the lamellae. It means that the fold surface area of the lamellae plays an important role in the transformation of radical (a) to (b). (C) 1997 Elsevier Science Ltd.

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Water-soluble polyhydroxylated fullerene derivatives (fullerenol) were synthesized, and their scavenging ability for (OH)-O-.-radical was studied by the combination of ESR spectroscopy and spin-trapping technique with phenyl-t-butyl-nitrone. It was found that fullerenols showed an excellent efficiency in eliminating (OH)-O-. free radicals generated by UV photolysis of H2O2. At an applied fullerenol concentration of 0, 3 mg/mL in the final solution, a radical scavenging efficiency of approximate 95% was achieved, revealing the potential use of these compounds as novel potent free radical scavengers in biological systems.

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The synthesis for lanthanofullerenes was studied by activating the La2O3 containing graphite rod in situ and back-burning the carbide-rich cathode deposite, La@C-2n are efficiently extracted in high temperature toluene, among them, La@C-74 as a new species is added into the soluble lanthanofullerenes, The toluene extraction is first characterized by desorption electron impact (DEI) mass spectrometry, The ESR spectrum of the extraction at room temperature is also discussed.

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采用对掺入La_2O_3的石墨棒原位活化并结合交换电极回放方法制备了产率较高的金属富勒烯,并用甲苯高温热提取的方法有效地提取出La@C_(2n),其中La@C_(74)为可溶性金属富勒烯增加了新成员.同时,首次采用解吸电子轰击质谱对提取物进行了表征,讨论了提取物的ESR谱.

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富勒醇清除·OH自由基的ESR研究祝严师,孙大勇,刘桂珍,刘子阳,詹瑞云,刘淑莹(中国科学院长春应用化学研究所应用谱学开放实验室,长春,130022)关键词C_(60),富勒醇,OH自由基,自旋捕捉,ESR生物体内的许多现象均涉及到自由基反应,现已发?..

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本文通过对不同条件下的Co(W_2O_7)_6~(10-)和CuW_(12)O_(40)~(6-)掺杂聚吡膜ESR谱线的分析并以相同条件下NO_3~-掺杂聚吡咯膜作为参照,表明杂聚阴离子不仅起着中和电性的作用,而且与聚吡咯分子链相作用形成某种加合物,它影响聚吡咯的电结构,这种加合物在过正或过负的电位下均不稳定.首次发现在CuW_(12)O_(40)~(6-)掺杂的干态聚吡咯膜具有Dysonian线型,表明膜中其它电结构的存在.

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ESR和自旅捕捉技术用于研究活体动物犬心肌缺血再灌产生的自由基,PBN从冠状静脉血液中捕捉到了OH自由基,直接地证实了缺血再灌细胞膜损伤的活性氧自由基作用机制;实验还看到一种甾体皂甙药物具有保护心肌细胞.防止自由基损伤的功能.

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本文通过WAXD,DSC方法讨论成核剂(Nd2O3)对PA1010的聚集态结构的影响。用ESR研究辐照不同聚集态结构PA1010体系的俘陷自由基行为。结果表明:俘陷自由基—CH2CONHCHCH2—主要存在于结晶表面,结晶的表面积越大,俘陷自由基—CH2CONHCHCH2—的含量越高,在一定条件下,如升温,常温放置一段时间,转化为俘陷自由基—CH2C=O的量也越大;俘陷自由基-CH2C=O主要存在于非晶区