Superconducting Wigglers

In low- and medium-energy storage rings for synchrotron radiation (SR) production, it is necessary to use high-performance insertion devices (IDs) in order to meet the increasing demand for high X-ray flux to perform life science and material science, since the maximum beam energy and beam current cannot be changed in storage rings without major rebuilds of the accelerator systems.     

Synchrotron radiation in Novosibirsk: The first 13 years

We describe the development of activity at the Siberian Center for Synchrotron and Terahertz Radiation at Budker Institute of Nuclear Physics (BINP), SB RAS, since 1974, when the history of experiments with synchrotron radiation (SR) in the world was just beginning–there were no dedicated sources of radiation and works can be carried out at several nuclear centers in the world. BINP made a significant contribution to the development of synchrotron radiation sources, and SB RAS institutes did their part for development of SR application to problems of chemistry, catalysis, biology, geology and materials science. The experiments were made at VEPP-3/VEPP-4 installation.     

Synthesis and structure study of ordered arrays of ZnSe nanodots

A novel approach is presented for synthesis of ZnSe nanodot arrays by physical vapor deposition on porous aluminum oxide templates with ordered channels. The structure of nanodots was studied by scanning electron microscopy and EXAFS spectroscopy. Data were obtained for the sizes of nanodots in the array and local atomic structure parameters, i.e., the interatomic distances and coordination numbers, in comparison with the data for the ZnSe film synthesized on a smooth surface of nonporous Al₂O₃.     

On the theory of chirped optical solitons in fiber lines with varying dispersion

We study a soliton solution of a path-averaged (in the spectral domain) propagation equation governing the transmission of a chirped breather pulse in the fiber lines with dispersion compensation. We demonstrate that the averaged Hamiltonian model correctly describes features of the chirped soliton observed in numerical simulations and experiments. We show that the Hamiltonian is bounded from below if the average dispersion is anomalous 〈 d〉>0); that, together with the condition H _sol<0, indicates stability of dispersion-managed solitons in this region. Pis’ma Zh. éksp. Teor. Fiz. 68, No. 11, 791–795 (10 December 1998) Published in English in the original Russian journal. Edited by Steve Torstveit.     

A multipole superconducting wiggler for Canadian light source

A contract for multipole superconducting wiggler design and fabrication between The University of Saskatchewan and Budker Institute of Nuclear Physics was signed in October 2003. A wiggler with the photons energy range 4 to 40 keV, the maximum field 1.9 T, and the period length as small as possible was required for the micro-XAFS beamline. In 2004 the 2 T 63-pole superconducting wiggler with the average period length 34 mm was fabricated in BINP. To eliminate the undulator-type spectrum, the periodicity of the wiggler was broken. A new approach to the cryostat design enabled long-time (up to 6 months) machine operation without liquid helium refilling (LHe consumption <0.03 l/h). After successful tests the wiggler was installed on the Canadian Light Source (CLS) storage ring with the energy 2.9 GeV in January 2005. The main parameters of the magnet and the cryogenic systems, as well as magnet measurements data, cryogenic system test data, and experimental results during machine operation on the CLS storage ring are presented.     

Measurement of the electron-atom collision integral in low-temperature helium plasma

An expression is obtained for the electron-atom collision integral for axisymmetric low-temperature plasmas. The Legendre components of the collision integral are determined experimentally by the probe method. Comparison of the measured Legendre components with their theoretical values shows that, depending on the plasma conditions, the collisional regime or a regime of dominant collective interactions is established in the system. Zh. Tekh. Fiz. 67, 19–24 (April 1997)     

Experimental study and mathematical modelling of heat transfer processes in heat accumulating media

Experimental results on reversing non-stationary heat transfer are presented for filtration of an air flow through an immobile heat accumulating medium consisting of lead (D = 2.0, 3.5, and 4.5 mm) and glass (D = 3.2 mm) balls. The studied device imitated the cyclic modes of heat regeneration in the ventilation system for domestic and office rooms. Dependency between the time of flow switching and Re number was measured. The mathematical model describing heat transfer between a gas flow and an immobile layer of balls was developed. Good correspondence between the experimental data and calculation results is observed for high Reynolds numbers. For low Re numbers the effect of heat losses is considerable, and experimental time of flow switching is shorter than the calculation one. The work was financially supported by the President of the Russian Federation (Grant No. NSh 6526.2006.3), Russian Foundation for Basic Research (Grant No. 06-08-00982), Foundation “Global energy” and Program “Energy saving of SB RAS”.