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1.
In 2011 the collinear laser spectroscopy programme at the University of Jyväskylä Accelerator Laboratory (JYFL), Finland, will move to the new IGISOL 4 facility. With its own dedicated cyclotron, this new laboratory will offer unparalleled access to beam time for both technique development and exploitation. Production of sub-millisecond states is available, including elements of a refractory nature.  相似文献   

2.
Michigan State University’s NSCL (National Superconducting Cyclotron Laboratory) is funded by the US National Science Foundation to operate the premier rare isotope user facility in the US. Beams of rare isotopes at NSCL are produced via projectile fragmentation or fission and separated in-flight. The current NSCL facility capabilities and main research directions will be outlined. The laboratory is currently expanding its capabilities by building an efficient gas-stopping and reacceleration capability initially up to 3.2 MeV per nucleon. For the longer term future, NSCL is proposing to replace the existing superconducting cyclotrons with a high-intensity, 200 MeV per nucleon superconducting heavy-ion linac.  相似文献   

3.
井下核磁共振流体分析实验室及其应用   总被引:1,自引:1,他引:0  
井下流体分析在储层实时评价有十分重要的应用. 该文介绍了NMR流体分析实验室的发展,并以哈里伯顿的井下NMR流体分析实验室为例, 详细讨论了其关键技术,包括探头结构、磁体结构和电路结构,探讨了获取流体核磁共振特性参数的测量方法. NMR流体分析实验室可以获取流体的多种重要参数,结合NMR测井能够进行综合解释,其实时评价性能实现NMR测量的优势.  相似文献   

4.
S L Chaplot 《Pramana》2006,67(1):163-171
A national facility for neutron beam research is operated at the research reactor Dhruva at Trombay in India. The research activities involve various nanoscale structural, dynamical and magnetic investigations on materials of scientific interest and technological importance. Thermal neutron has certain special properties that enable, e.g., selective viewing of parts of an organic molecule, hydrogen or water in materials, investigations on minerals and ceramics, and microscopic and mesoscopic characterization of bulk samples. The national facility comprises of eight neutron-scattering spectrometers in the reactor hall, and another four spectrometers in the neutron-guide laboratory. In addition, a neutron radiography facility and a detector development laboratory are located at APSARA reactor. All the instruments including the detectors and electronics have been developed within BARC. A new powder diffractometer (PD-3) is being developed by UGC-DAE-CSR. The national facility is utilized in collaboration with various universities and other institutions.  相似文献   

5.
The IGISOL (Ion Guide Isotope Separator On-Line) facility at the University of Jyväskylä accelerator laboratory has been upgraded and relocated to a purpose built laboratory. The new laboratory includes a dedicated MCC30 proton/deuteron cyclotron, which in conjunction with beams from the K130 cyclotron, will greatly increase the beam time available at the facility. Full off-line commissioning of the laser spectroscopy beam-line was achieved in February 2013 and on-line commissioning with radioactive beams was achieved in May 2013. Optical hyperfine resonance spectra were obtained for previously studied radioactive molybdenum isotopes and used to investigate our long term stability, efficiency and ability to successfully reproduce previous results from IGISOL III. A preliminary spectrum for the previously unmeasurable $^{107}$ Mo was collected, displaying the improved capabilities of the new facility. Both data-sets show that the laser-line is ready for future experiments. The IGISOL IV beams are cleaner and have a higher radioactive content compared to similar experiments at IGISOL III.  相似文献   

6.
核磁共振(NMR)波谱是研究有机分子结构的重要工具之一,其设备昂贵、仪器数量有限、科研机时安排紧凑、教学实验机时有限;若学生的NMR理论和实验基础较为薄弱,则易发生误操作损坏设备或降低设备性能;另外,NMR实验涉及流程较多、教学耗时较长.因此,针对学生的NMR实验教学难以广泛开展.为将虚拟技术更好地用于辅助NMR实验教学,本文基于数值模拟仿真技术,开发了具备真实NMR波谱仪基本功能的仿真NMR波谱仪——VMRS1.0软件.VMRS1.0软件可实现真实NMR实验须进行的调谐匹配、匀场、锁场、射频脉冲调节、原始数据采集等操作步骤,以及快速傅里叶变换、相位校正、自动寻峰、积分、测距、化学位移校正等基本数据处理功能;除简单的1D 1H和13C NMR波谱采集和数据处理外,还可模拟去偶、DEPT、HSQC等相对复杂的实验;另外,该软件可自行虚拟编辑1H或13C NMR实验样品.VMRS1.0软件摆脱硬件条件的限制,实现了与真实NMR实验类似的教学效果,可以让学生通过反复操作调试,更充分地掌握NMR基本原理和实验技能,再配合在真实NMR谱仪上的少量实际操作,可达到更加令人满意的实验教学效果.  相似文献   

7.
An experimental laboratory setup combining various gamma spectrometers and neutron generators that is intended for operating at the experimental nuclear-planetology facility deployed at the Joint Institute for Nuclear Research (Dubna, Russia) in order to perform physical calibrations of active gamma and neutron spectrometers is described.  相似文献   

8.
详细介绍了我们在386微机上建立的二维NMR数据处理与分析系统,该系统采用菜单驱动方式,具有良好的用户界面,可进行标准的常规二维NMR数据处理与分析,数据处理结果可由标准设备输出或者以文件方式存储以便其它应用软件处理,该系统的建立可使通用微计算机成为有效的核磁共振数据处理站。  相似文献   

9.
An escape-suppressed, composite high-purity germanium detector of the Clover type has been installed at the Laboratory for Underground Nuclear Astrophysics (LUNA) facility, deep underground in the Gran Sasso Laboratory, Italy. The laboratory $ \gamma$ -ray background of the Clover detector has been studied underground at LUNA and, for comparison, also in an overground laboratory. Spectra have been recorded both for the single segments and for the virtual detector formed by online addition of all four segments. The effect of the escape suppression shield has been studied as well. Despite their generally higher intrinsic background, escape-suppressed detectors are found to be well suited for underground nuclear-astrophysics studies. As an example for the advantage of using a composite detector deep underground, the weak ground-state branching of the E p = 223 keV resonance in the 24Mg(p, $ \gamma$ )25Al reaction is determined with improved precision.  相似文献   

10.
Physics with ultra-relativistic heavy ions at three different accelerators SPS at CERN and AGS and RHIC at BNL is reviewed. The physics discussed ranges from global event characteristics through direct photon production, proton-proton correlation studies to Quark Gluon Plasma (QGP) phase trasition signatures via dileptonic, photonic and hadronic signals.Invited lecture given at the International School-Workshop Relativistic Heavy-Ion Physics, Prague (Czech Republic), 19–23 September 1994.Managed by Martin Marietta Energy Systems, Inc., under contract DE-AC05-84OR21400 with the U.S. Department of Energy.In conclusion, I have indicated that the RHIC project is well underway, and that the two major experiments planned for the facility, PHENIX and STAR, are being implemented with broad capabilities to address future exciting physics issues. A strong argument can be made that European groups should join the RHIC effort even with the advent of the LHC project at CERN. Aside from covering different energy regions, the two projects are shifted in time by over five years relative to each other, and RHIC is a machine dedicated to nucleus-nucleus studies, while the LHC will be available only on a limited basis.  相似文献   

11.
The relativistic heavy ion collider (RHIC) is a proposed facility at Brookhaven National Laboratory for very high energy collisions of nuclear beams. The project has had a substantial amount of R and D effort and is ready to begin construction within the next year of two, as funding permits. We describe the parameters of the machine, discuss the current status of development work on the project, and describe the requirements for experiments at such a facility.  相似文献   

12.
There are several nuclear physics laboratories in North America that have on-going research using energetic and stopped radioactive beams. These include the large ISOL-type programs ISAC at TRIUMF and HRIBF at Oak Ridge and the in-flight fragmentation program at the NSCL of Michigan State University. There are also smaller, more specialized, programs using a variety of techniques at the 88-inch cyclotron of Berkeley, ATLAS at Argonne, the Cyclotron Institute of Texas A&M University, the Nuclear Structure Laboratory at Notre Dame University, and the Nuclear Structure Laboratory at SUNY/Stony Brook. There are also three projects on the horizon in North America for new capabilities in both the near term and more distant future. The intensities of the in-flight fragment beams at the NSCL will be increased dramatically very soon as the Coupled Cyclotron Project will be completed and commissioned for research by mid-2001. A new project, ISAC-II, has been approved in Canada. For the longer term, the United States is considering construction of a major new facility, the Rare Isotope Accelerator (RIA), which would have a very high-intensity heavy-ion driver linac. The RIA facility is proposed to utilize both ISOL and in-flight production mechanisms. Received: 1 May 2001 / Accepted: 4 December 2001  相似文献   

13.
The story of ISABELLE, a colliding-beam accelerator conceived in 1971, officially approved in 1978, partially constructed, and terminated in 1983, is an important episode in the history of post-World War II science in the United States.The events surrounding its planning, construction, and termination reveal much about the ambitions, strategies, and tensions of American high-energy physicists, their collaborations and rivalries, and the difficulties of funding and constructing a large scientific facility in the age of Big Science. In this article, the first of two parts, I cover the period up to the beginning of construction in 1978. I place ISABELLE in the context of the early history of colliders, outline the physics goals that motivated the machine, and describe the research and motivations behind its innovative but ultimately problematic superconducting magnet design. I cover the key technological and administrative steps that the laboratory took to get the project underway and steer it past several review committees. I also treat some of the conflicts within the laboratory, and between Brookhaven and other laboratories, especially Fermilab, that hampered the project. Robert P. Crease is a Professor in the Department of Philosophy of Stony Brook University in Stony Brook, New York, and historian at Brookhaven National Laboratory.  相似文献   

14.
Abstract

The calibration procedures needed for use of dispersive Raman spectrometers have been reviewed. Like other high‐precision spectrometers incorporating moving gratings, Raman spectrometers are subject to problems with wavenumber scale accuracy. Commercially available Raman spectrometers of types DILOR‐HORIBA LabRam and RENISHAW System 1000 have been examined for wavenumber scale stability, linearity, and reproducibility. For reliable use of the wavenumber data, daily calibration is a necessity. A procedure to examine the linearity of such mechanical drive systems is presented. A new finding was that the examined spectrometers give wavenumber calibration errors that were quite reproducible from day to day at a given temperature in the laboratory but depended markedly on the selected setting of the gratings. Knowledge of this linearity problem is essential for obtaining a reliable calibration. The most correct calibration was obtained by the use of certain “golden” settings of the sinus drive at a constant temperature of the laboratory. In this way, the examined spectrometers could be used with better precision, without daily calibration, provided the temperature of the room was constant or corrected for. A procedure for correction of these errors by the software is suggested.  相似文献   

15.
Since its discovery in 1946, NMR has become a valuable tool in physics, chemistry, biology, and medicine. With the invention of NMR logging tools that take the medical MRI or laboratory NMR equipment and turn it inside-out, the application of sophisticated laboratory techniques to determine formation properties in situ is now available. The capability has opened a new era in formation evaluation just as the introduction of NMR has revolutionized the other scientific areas.  相似文献   

16.
The LUNA (Laboratory Underground for Nuclear Astrophysics) facility has been designed to study nuclear reactions of astrophysical interest. It is located deep underground in the Gran Sasso National Laboratory, Italy. Two electrostatic accelerators, with 50 and 400 kV maximum voltage, in combination with solid and gas target setups allowed to measure the total cross-sections of the radiative-capture reactions ^2H2H(p, )^3He3Heand ^14N14N(p, )^15O15Owithin their relevant Gamow peaks. We report on the gamma background in the Gran Sasso laboratory measured by germanium and bismuth germanate detectors, with and without an incident proton beam. A method to localize the sources of beam-induced background using the Doppler shift of emitted gamma rays is presented. The feasibility of radiative-capture studies at energies of astrophysical interest is discussed for several experimental scenarios.  相似文献   

17.
Magnetic spectrometers of charged nuclear reaction products, properly matched with an accelerator beam line, have become a very effective setup for the performance of precise nuclear experiments involving ultrasensitive accelerator-based mass spectrometry and investigation of rare events, as well as experiments with radioactive nuclear beams. The procedure for increasing the efficiency and resolution of the available magnetic spectrometer at the Flerov Laboratory of Nuclear Reactions by a few orders of magnitude by means of its matching with the beam line is described.  相似文献   

18.
贝加尔(Baikal)装置是当今世界上在建的最大的脉冲功率驱动热核聚变和高能量密度研究装置,从最初建造贝加尔装置概念的提出,其技术路线和主要参数经历了一系列的发展和演变过程。综合介绍了贝加尔装置概念设计提出的历史背景、发展演变过程和目前的研究进展,描述了贝加尔装置的主体性能和技术路线,着重分析了装置主要部件的结构和性能参数。  相似文献   

19.
We examine the roles of vision and leadership in creating and directing Fermi National Accelerator Laboratory from the late 1960s through the 1980s. The story divides into two administrations having different problems and accomplishments, that of Robert R. Wilson from 1967-1978, which saw the transformation from cornfield to frontier physics facility, and that of Leon M. Lederman from 1979-1989, in which the laboratory evolved into one of the world's major high-energy facilities. Lederman's pragmatic vision of a user-based experimental community helped him to convert the pioneering facility that Wilson had built frugally into a laboratory with a stable scientific, cultural, and funding environment.  相似文献   

20.
High-resolution 13C spectra of solid polymers are often acquired with cross polarization with magic angle spinning (CP/MAS) to take advantage of the abunda ntly available protons in the polymer chains. The sequence for transferring mag netization from 1H to13C using Hartmann-Hahn spin locking in the rotating frame is now a standard in commercial solidstate NMR spectrometers.  相似文献   

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