Igor I. Sobel'man

Comprehensive studies of solar activity on the CORONAS-F satellite

The first results of comprehensive CORONAS-F observations of solar activity are presented. The CORONAS-F instrumentation and principal scientific objectives are briefly described and examples of the first results of data reduction are given.

Precision laser spectropolarimetry

A procedure for precision measurements of small angle rotation of light polarization plane vs wavelength is described. Analyzed at length is the optical spectropolarimeter configuration, wherein the frequency-dependent instrumental rotations are suppressed to the maximum degree. The sensitivity and the accuracy of the technique are illustrated by the examples of measuring the optical activity of atomic bismuth caused by parity nonconservation and the spectral profiles of the Faraday rotation.

Another look at what is possible and impossible in optics

According to the Lagrange-Helmholtz law, no optical system can ever increase the brightness (and therefore the effective temperature) of a light beam. This limitation is frequently interpreted as a consequence of the second law of thermodynamics. Actually, thermodynamics imposes no limitations of practical importance on the possibilities of increasing the brightness of light beams: the decrease of the entropy of the light beam associated with the increase of its brightness can be compensated by a loss of a negligible fraction of the energy of the beam. The general discussions are illustrated by a number of specific examples.

Neutron spin filter based on optically polarized in a near-zero magnetic field

Abstract A test of polarization of 3 He nuclei via spin-exchange collisions with optically pumped rubidium atoms in an extremely low applied magnetic field was carried out. Permalloy magnetic shields were used to prevent a fast relaxation of 3 He polarization owing to the inhomogeneity of a surrounding magnetic field. The whole installation was placed at the neutron beam line of the IBR-30 facility, and used as a neutron spin filter. Thus, a prototype of new design of neutron polarizer was introduced. We intend to apply this experience for the full-scale KaTRIn facility to test the time reversal violation in neutron-nuclear reactions.

Erratum: Comprehensive studies of solar activity on the CORONAS-F satellite [Astronomy letters 28, 401–410 (2002)]

The first results of comprehensive CORONAS-F observations of solar activity are presented. The CORONAS-F instrumentation and principal scientific objectives are briefly described and examples of the first results of data reduction are given.

The Hydrogen Spectrum

The hydrogen atom and its spectrum treated in this chapter are of special interest in atomic spectroscopy because only for the hydrogen atom can the Schrodinger and Dirac equations be solved analytically. So-called hydrogenlike approximations are widely used in the theory of atomic spectra.

Collision broadening of spectral lines corresponding to transitions between excited levels of the cesium atom

The constants of pressure self-broadening of cesium have been measured for the transitions 6P1/2−8D3/2, 6P3/2−10S1/2, and 5D5/2−nF(n=14−19). The constants of the resonance broadening of the 6P1/2 and 6P3/2 cesium levels, the constants of electron collisional broadening of thenF levels at a temperature ofT≈1500 K, and the oscillator strengths of the 5D5/2−nF(n=14−18) transitions have been determined.

Spectra of Multielectron Atoms

This chapter contains a brief discussion of the specific features of the spectra of multielectron atoms belonging to various groups of the periodic table according to successive filling of electron shells.

Spectra of Multicharged Ions

The spectra of multicharged ions are of special interest to many modern fields of research, such as X-ray space astronomy and astrophysics, controlled thermonuclear fusion, extreme ultraviolet and soft X-ray lasers. Different methods of creating high-temperature laboratory plasmas, low-inductance sparks and other discharges, tokomak and laser-produced plasmas, have been used to study the spectra of ions with ion charges of Z i ≲50. Increasing activity in investigating the structure of highly charged heavy ions is stimulated by unique possibilities provided by modern accelerators and beam-foil spectroscopy. Fast heavy few-electron ions can be produced by stripping electrons from sufficiently accelerated ions shot through a thin foil. The higher the ion energy is, the higher the charge state that can be created behind the foil. A very impressive example of this technique is the production of hydrogenlike uranium.

Systematics of the States of Multielectron Atoms

Systematics of the levels of multielectron atoms, term structure, and fine splitting are treated in detail using the Racah techniques in the theory of angular momenta and the Racah method of fractional parentage coefficients. There are numerous examples throughout the text which enable one to use these very effective methods in different problems of atomic physics.