In this article, a method for measuring the magnetic fields of wigglers and undulators based on a wire with a pulsed current as a high-speed alternative to Hall measurements is considered. An experimental setup for measurements is described. Correcting algorithms of the initial data are applied in order to eliminate the influence of wire dispersion and electronics noise. The obtained results and further work are discussed.

The CBM detector will research compressed baryon matter on the FAIR facility, GSI, Darmstadt. The superconducting dipole magnet of this detector provides vertical magnetic field with field integral ∼ 1 T*m along a beam length of 1 m. The warm bore distance between the dipole coils is 1.44 m. Maximal magnetic field on the superconducting winding is 3.6 T. The stored energy of the magnet is ∼ 5 MJ. The superconducting coils having 1.34 m of inner diameter will be made of NbTi wire having Cu/SC ratio of 7/1. The SC wire cross-section bare size is 2.02 mm × 3.25 mm. This wire of 30 km of total length in 6 pieces was manufactured by extrusion monolith technique. The iron yoke having 139 t weight is a part of the CBM magnet. It was manufactured and assembled. The SC coils were designed according the indirect cooling principle. The superconducting winding is embedded in copper case and will be cooled by 4.5 K helium going through the copper tube attached to the copper case. Two dummy coils were manufactured and tested to choose the epoxy impregnation procedure. The cooling helium will circulate between the cryostat containing 150 l of LHe and two coils in thermosyphone regime in single loop. The vapor quality at the outlet of the thermosyphone loop is ∼ 10%. The each coil is affected by 3 MN axial force towards the nearest iron yoke. The single cylinder GFRP support strut was designed to withstand this force to have the safety factor > 4 with respect to the ultimate strength and buckling. The GFRP material was chosen and tested.

A superconducting undulator created at the Budker Institute of Nuclear Physics with a period of 15.6 mm and a field of 1.2 T is tested in own undulator cryostat based on indirect cooling with zero helium consumption. The main characteristics and design features of the magnetic and cryogenic systems of this insertion device are presented. Results from measuring the magnetic field are presented. Features of the operation of a cryogenic system in different modes are discussed.

The main devices for generating synchrotron radiation at the SKIF synchrotron light facility under construction will be superconducting wigglers and undulators created at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences. This report presents the rationale for the choice of operating parameters, the main characteristics and design features of these devices, and their current development status.

The authors describe a way of tuning the magnetic field of a superconducting undulator with neutral poles developed at the Budker Institute of Nuclear Physics, along with a mathematical apparatus for calculating additional power currents for tuning a magnetic field. The field and orbit inside the undulator are tuned by primary undulator windings arranged into separate groups and powered by additional currents. The tuning circuit is tested, and theoretical and experimental data on the measured magnetic field and calculated phase errors are compared. Spectra of synchrotron irradiation before and after tuning are calculated with the SPECTRA software.

At the FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) accelerator complex under construction, one of the key experiments is the PANDA experiment. The main field of the PANDA spectrometer is provided by a superconducting solenoid. The energy of the magnetic field stored in a superconducting solenoid reaches 22 MJ at an operating current of 5100 A. In the case of the transition of the superconducting cable used for the solenoid winding into a resistive state, the safe extraction of stored energy is required to protect the magnet. The energy extraction system proposed by the authors provides energy dissipation inside the external dump resistor, and not in the section of the superconducting cable that has passed into resistive state, while preventing its damage. The most critical elements of the energy extraction system are the current breaker, with the help of which the dump resistor is introduced into the power circuit of the superconducting solenoid, and the dump resistor itself. A modernized three-phase circuit breaker was chosen as current breaker. A unique design of the energy extraction system including dump resistor with a low parasitic inductance has been developed.

Recent discoveries in nonlinear optical properties of nanoparticle colloids make actual the challenge to lower the energy threshold of phase conjugation and move it into the domain of shorter pulse widths. A novel effect of the stimulated Rayleigh-Mie scattering (SRMS) in two-photon absorbing nanocolloids is considered as a promising answer to this challenge. We report the results of experimental and theoretical study of the two-photon-assisted SRMS in Ag and ZnO nanocolloids in the nanosecond-to-picosecond pulse width domain. For 12 ns 0.527 μm laser pulses, the four-wave mixing SRMS scheme provides lasing and amplification of backscattered anti-Stokes signal in Ag nanocolloids in toluene at the threshold 0.2 mJ and the spectral shifts up to 150 MHz. For 100 ps 0.532 μm pulses, we observed for the first time efficient (over 50% in signal-to-pump ratio of pulse energies) SRMS backscattering of the anti-Stokes signal in Ag nanocolloids in toluene and predominantly Stokes signal in ZnO nanocolloids in water, with the spectral shifts up to 0.25 cm−1. We develop the first order-in-perturbation model of the four-wave mixing two-photon absorption-assisted SRMS process which shows that at nanosecond pulses, amplification is predominantly due to the thermal-induced coherent oscillations of polarization while the slow temperature wave acts also as a dynamic spatial grating which provides a self-induced optical cavity inside the interaction region. At a picosecond pulse width, according to our model, the spectral overlap between pump and signal pulses results in formation of only the dynamic spatial temperature grating, and we succeeded at recovering the linear growth of the spectral shift with the pump power near the threshold.

In this paper, an infinite waveguide of an arbitrary constant cross-section with losses in the walls described by the Shchukin-Leontovich boundary conditions with a variable impedance along the cross-sectional boundary is investigated. To solve the problem of calculating hybrid eigenmodes of the waveguide with impedance boundary conditions, mathematical model based on representing the field as a sum of Borgnis functions of electric and magnetic types in combination with the finite element method is considered. As a result, the original boundary value problem is reduced to solving a generalized algebraic eigenvalue problem.By using the proposed model, the eigenmodes of the waveguide in the terahertz range are calculated, the dispersion characteristics are constructed, and the evolution of the spectrum depending on the impedance distribution at the waveguide boundary is investigated.

Superconducting multipole insertion devices (wigglers and undulators) used to generate synchrotron radiation significantly increase the photon flux, especially in the hard spectral region. Over the past 35 years, more than 25 superconducting wigglers for leading centers of synchrotron radiation have been created at the BINP. A cryogenic system based on cryocoolers has been developed, which makes is possible to operate superconducting insertion devices for several years without consuming liquid helium. In this paper, the characteristics of various superconducting insertion devices created at the BINP are presented. The design features and recent advances in the development of the magnetic and cryogenic system with liquid and indirect cooling are discussed.

The efficiency of a real heat engines is considered. Basing on the entropy production minimum principle it is shown that the maximum efficiency of such a machine with an optimum power is n= 1-√T2/T1 defined by the root dependence of cooler and heater temperatures. This disappointing result was obtained earlier for the optimizing the power of Carnot cycle. In this paper we derive aforementioned expression from more general conditions. And we show that it is could be applicable to describe global changes in living and nonliving nature.

A method for constructing eigenmodes of an infinite waveguide of a constant rectangular cross section with low losses in the walls, which are described by the Shchukin—Leontovich boundary conditions, is discussed. The dispersion characteristics of these waveguides are constructed.

The shapes and the sizes of metal oxide particles in polymer-stabilized disperse systems subjected to mechanical activation are considered. The digital processing of images of metal oxide particles is used to determine the parameters of the particles and the adsorbed polymer layers and to find the density change dynamics in an adsorbed layer.

A superconducting wiggler with a magnetic field of 7 T is installed as an insertion device for three X-ray beamlines with photon energies of more than 30 keV used at the Dortmund Electron Accelerator (DELTA, Germany), a source of 1.5 GeV synchrotron radiation. Each of the two side beamlines is separated from the central one by 15 mrad and all three beamlines use a horizontal aperture of 5 mrad. To meet these requirements, the insertion device must have a period of 127 mm and a magnetic field of 7 T for the vertical aperture of a beam vacuum chamber 10 mm long and a flange-to-flange distance of 2.2 m. A superconducting 22-pole wiggler with a field of 7 T and a period of 127 mm operating in the zero boil-off mode is described. The concept and main approaches to designing the magnetic and the cryogenic systems are presented, along with the main parameters and results from testing the new 7-tesla superconducting wiggler for the DELTA storage ring.

The spectral characters and increments of stimulated Rayleigh scattering in pure liquids and suspensions of Ag nanoparticles in toluene and hexane of principally different nature were investigated in this work. The correlation of two photon absorption spectra and stimulated scattering efficiency were discovered and analyzed. It is shown experimentally that the frequency shift of the scattered signal relative to the pump frequency greatly exceeds the theoretical value.

A method for computing a perfectly conducting periodic rectangular waveguide of the ladder type is proposed. A field transformation matrix is constructed that relates the complex amplitudes of the field in waveguide cross sections separated by the distance equal to the period of the system. The dispersion characteristics of a periodic waveguide operating in the terahertz range are calculated.

We report the results of the experimental and theoretical study of stimulated temperature scattering in toluene and hexane solutions of Ag-nanoparticles, as well as in pure toluene in the two-photon absorption regime. A four-wave mixing scheme with two counter-propagating pump waves of the same frequency is utilised to demonstrate the lasing effect and the amplification of the backscattered anti-Stokes signal. For the first time, we have measured anti-Stokes spectral shifts which turn out to appreciably exceed the Rayleigh line widths in those liquids. It is shown that the amplification effect is provided predominantly by thermally induced coherent polarisation oscillations, while the dynamic interference temperature grating causes the formation of a self-induced optical cavity inside the interaction region.