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1.
In the early 1970s, the Institute of Nuclear Physics (INP) in Novosibirsk was a unique place in the world of accelerator physics. There were three operational electron-positron storage rings at the institution. All together, they covered beam operational energies from 200 MeV up to 2.2 GeV. It was not a big surprise for the developers of these state-of-the-art machines when the first users of synchrotron radiation showed up at the doorsteps of the Institute of Nuclear Physics, eager to take advantage of such unique radiation sources. And how very unique they were! Compared with several already relatively well-established operational synchrotrons around the world, such as DESY in Hamburg, NINA in Darsbury, and three synchrotrons in the Soviet Union—one at the Physical Institute in Pakhra, another at the Tomsk Polytechnical Institute, and a third at the Erevan Physical Institute—the storage ring sources provided much more stable and brighter radiation beams. Several storage rings built at that time in locations such as Japan, the US, and France were also on the verge of becoming available for synchrotron radiation users.  相似文献   

2.
A radio-frequency (RF) gun for a race-track microtron-recuperator injector driving the free-electron laser (FEL) (Budker Institute of Nuclear Physics) is being tested at a special stand. Electron bunches of the RF gun have an energy of up to 300 keV and a repetition rate of up to 90 MHz. The average electro-beam current can reach 100 mA in the continuous operation regime. The advantages of the new injector are as follows: long lifetime of the cathode for high average beam current; simple scheme of longitudinal beam bunching, which does not require an additional bunching resonator in the injector; absence of dark-current contamination of the injector beam; and comfortable RF gun operation due to the absence of a high potential of 300 kV at the cathode control circuits. In this study we describe the RF gun design, present the main characteristics of the injector with the RF gun, and give the results of testing.  相似文献   

3.
An accelerator mass spectrometer (AMS) made at the Budker Institute of Nuclear Physics (BINP), Siberian Branch, Russian Academy of Sciences, is installed in the Geochronology of the Cenozoic Era Center for Collective Use for the carbon 14 dating of samples. Distinctive features of the BINP AMS include the use of a middle energy separator of ion beams, magnesium vapor target as a stripping target, and a time-of-flight telescope with thin films for accurate ion selection. Results of experiments measuring the radiocarbon concentration in test samples with radiocarbon labels for biomedical applications are presented.  相似文献   

4.
A project of a Super Charm-Tau factory is being developed at the Budker Institute of Nuclear Physics (Siberian Branch, Russian Academy of Sciences) in Novosibirsk. The electron-positron collider to be employed will operate at c.m. energies in the range between 2 and 5 GeV at an unprecedentedly high luminosity of 1035 cm?2 s?1 with a longitudinal electron polarization at the beam-interaction point. The main objective of experiments at the Super Charm-Tau factory is to study processes involving the production and properties of charmed quarks and tau leptons. A high luminosity of this setup will make it possible to obtain a statistical data sample that will be three to four orders of magnitude vaster than that from any other experiment performed thus far. Experiments at this setup are assumed to be sensitive to effects of new physics beyond the Standard Model. Investigations to be carried out at the Super-Charm-Tau factory will supplement future experiments at Super-B factories under construction in Italy and in Japan.  相似文献   

5.
The efficiency of injection from a linear accelerator into the damping ring of the BINP injection complex has been experimentally studied. The estimations of the injection efficiency are in good agreement with the experimental results. Our method of increasing the capture efficiency can enhance the productivity of the injection complex by a factor of 1.5–2.  相似文献   

6.
P Mukherjee 《Pramana》2001,57(1):5-9
Experimental studies of nuclear excitations have been an important subject from the earliest days when the institute was established. The construction of 4 MeV proton cyclotron was mainly aimed to achieve this goal. Early experiments in nuclear spectroscopy were done with radioactive nuclei with the help of beta and gamma ray spectrometers. Small NaI(Tl) detectors were used for gamma-gamma coincidence, angular correlation and life time measurements. The excited states nuclear magnetic moments were measured in perturbed gamma-gamma angular correlation experiments. A high transmission magnetic beta ray spectrometer was used to measure internal conversion coefficients and beta-gamma coincidence studies. A large number of significant contributions were made during 1950–59 using these facilities. Proton beam in the cyclotron was made available in the late 1950’s and together with 14 MeV neutrons obtained from a C-W generator a large number of short-lived nuclei were investigated during 1960’s and 1970’s. The introduction of high resolution Ge gamma detectors and the improved electronics helped to extend the spectroscopic work which include on-line (p 7 p′γ) and (p 7 ) reaction studies. Nuclear spectroscopic studies entered a new phase in the 1980’s with the availability of 40–80 MeV alpha beam from the variable energy cyclotron at VECC, Calcutta. A number of experimental groups were formed in the institute to study nuclear level schemes with (α 7 xnγ) reactions. Initially only two unsuppressed Ge detectors were used for coincidence studies. Later in 1989 five Ge detectors with a large six segmented NaI(Tl) multiplicitysum detector system were successfully used to select various channels in (α 7 xnγ) reactions. From 1990 to date a variety of medium energy heavy ions were made available from the BARC-TIFR Pelletron and the Nuclear Science Centre Pelletron. The state of the art gamma detector arrays in these centres enabled the Saha Institute groups to undertake more sophisticated experiments. Front line nuclear spectroscopy works are now being done and new informations are obtained for a large number of nuclei over a wide mass range. Currently Saha Institute is building a multi-element gamma heavy ion neutron array detector (MEGHNAD), which will have six high efficiency clover Ge detector together with charged particle ball and other accessories. The system is expected to be usable in 2002 and will be used in experiments using high energy heavy ions from VECC.  相似文献   

7.
MANORANJAN SARKAR 《Pramana》2011,76(2):293-312
This paper covers different aspects related to X-ray fluorescence activities at Saha Institute of Nuclear Physics, Kolkata, India. In its first part, experiments on basic physical problems are illustrated and in the second part, some applications related to X-ray fluorescence are discussed.  相似文献   

8.
Leupold  O. 《Hyperfine Interactions》2002,144(1-4):21-32
Since its observation in 1985 nuclear resonant scattering of synchrotron radiation has become an excellent tool to study hyperfine interactions in solids. It combines the advantages of both local probe experiments and scattering techniques and gives valuable information on magnetic and electronic structures in case of NFS experiments. Experiments benefit from the outstanding beam quality of 3rd generation synchrotron radiation sources, as the small beam size and divergence. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

9.
What is mesoscale science? The modifier “meso” can mean different things to different communities. In many areas of science, “mesoscale” generally refers to a middle-ground domain of length, energy, or time where theories accurate at both lower and higher scales fail. In materials science, for example, mesoscale behavior often rises when quantum behavior begins to fade, collective effects become important, or statistical variation and defects appear, often at length scales larger than a few nm. However, for atmospheric scientists and ecologists, mesoscale means miles. For meterologists, mesoscale means hundreds to thousands of miles. The mesoscale arena for cosmologists is many light-years across.  相似文献   

10.
11.
The history and modern state of the development of electron-beam accelerators at the Skobeltsyn Institute of Nuclear Physics at Moscow State University and investigations with their use are considered.  相似文献   

12.
大结构深度和高深宽比是同步辐射深度光刻的突出优点.提出采用现有掩模,进行多次曝光、显影的方法,实验获得厚2.2mm的胶结构.系列研究掩模、光刻胶、基底、光谱和光强对深宽比的影响,实验获得深宽比104的胶结构.  相似文献   

13.
Physics of Atomic Nuclei - Work on the conceptual design of a dedicated fourth-generation fourth-generation Specialized Synchrotron Radiation Source (SSRS-4) is in progress at the Kurchatov...  相似文献   

14.
van Bürck  U.  Potzel  W.  Schindelmann  P.  Smirnov  G. V.  Popov  S. L.  Gerdau  E.  Shvyd'ko  Yu. V.  Rüter  H. D.  Leupold  O. 《Hyperfine Interactions》2002,141(1-4):151-155
The radiation fields reemitted in nuclear forward scattering of synchrotron radiation by a system of two single-line targets of highly different linewidths mounted downstream behind each other were analyzed by applying a stepwise energy shift to one of the targets. The results reveal a pronounced dependence of the fields on target sequence, which demonstrates the important role of radiative coupling. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

15.
The year 2016 marks the 60th anniversary of the Joint Institute for Nuclear Research (JINR) in Dubna, an international intergovernmental organization for basic research in the fields of elementary particles, atomic nuclei, and condensed matter. Highly productive advances over this long road clearly show that the international basis and diversity of research guarantees successful development (and maintenance) of fundamental science. This is especially important for experimental research. In this review, the most significant achievements are briefly described with an attempt to look into the future (seven to ten years ahead) and show the role of JINR in solution of highly important problems in elementary particle physics, which is a fundamental field of modern natural sciences. This glimpse of the future is full of justified optimism.  相似文献   

16.
Seto  M.  Kitao  S.  Kobayashi  Y.  Haruki  R.  Mitsui  T.  Yoda  Y.  Zhang  X. W.  Kishimoto  S.  Maeda  Y. 《Hyperfine Interactions》2002,141(1-4):99-108
We achieved excitation of the first excited state of 40K and confirmed both energy and lifetime. Furthermore, we observed nuclear resonant inelastic scattering by 40K in a powdered KCl sample at room temperature using a high-resolution monochromator. The time spectrum of the nuclear resonant forward scattering was measured at 50 K. Our observations of nuclear resonant inelastic and forward scattering by 40K make electronic and dynamic studies for potassium practical. The measurements of nuclear resonant scattering for the radioactive 40K nuclide will enable and lead to further studies of other radioactive nuclides. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
18.
The European Physical Journal H - This is a tutorial for the many-worlds theory by Everett, which includes some of my personal views. It has two main parts. The first main part shows the emergence...  相似文献   

19.
A compact high precision eight-axis automatism and two-axis manual soft-ray polarimeter with a multilayer has been designed, constructed, and installed in 3W1B at the Beijing Synchrotron Radiation Facility (BSRF). Four operational modes in the same device, which are double-reflection, double-transmission, front-reflection-behind-transmission and front-transmission-behind-reflection, have been realized. It can be used for the polarization analysis of synchrotron radiation. It also can be used to characterize the polarization properties of the optical elements in the soft X-ray energy range. Some experiments with Mo/Si and Cr/C multilayers have been performed by using this polarimeter with good results obtained.  相似文献   

20.
Held only weeks after the SRS had delivered its last photon beams (from September 11?12, 2008), the 2008 UK Synchrotron Radiation User Meeting was a mixture of nostalgia, news and next steps. Prof. Chris Hardacre, Chairman of the User Forum, welcomed everyone to the meeting and opened the session reserved for updates from the sources mostly used by the UK community. Dr. Tracy Turner began by showing a short video clip of the last seconds of multibunch user beam at the official SRS switch off ceremony on August 4. Highlighting several recent results to illustrate the point, she described how the SRS had been productive right up to the end with a late surge in operational reliability in both multibunch and single bunch modes. Over 400 papers have already been published this year, and many of these in high impact factor journals. She announced the imminent publication of the final Annual Report and a survey of the economic impact made by the SRS over its lifetime which had been prompted by the impending closure and which will be informative to government and other bodies in assessing the benefits that accrue from investment in large-scale facilities.  相似文献   

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