Alexander Kholmetskii

Kündig's experiment on the transverse Doppler shift re-analyzed

In this paper, we re-analyze the ingenious experiment by Kundig (measurement of the transverse Doppler shift by means of the Mossbauer effect) and show that a correct processing of experimental data gives a relative energy shift 1E/E of the absorption line different from the value of classically assumed relativistic time dilation for a rotating resonant absorber. Namely, instead of the relative energy shift 1E/E = (1.0065± 0.011)v 2 /2c 2 reported by Kundig (v being the linear velocity of absorber and c being the light velocity in vacuum), we derive from his results 1E/E = (1.192± 0.011)v 2 /2c 2 . We are inclined to think that the revealed deviation of 1E/E from relativistic prediction cannot be explained by any instrumental error and thus represents a physical effect. In particular, we assume that the energy shift of the absorption resonant line is induced not only by the standard time dilation effect, but also by some additional effect missed at the moment, and related perhaps to the fact that resonant nuclei in the rotating absorber represent a macroscopic quantum system and cannot be considered as freely moving particles.

A Mössbauer experiment in a rotating system on the second-order Doppler shift: confirmation of the corrected result by Kündig

We present the results of a Mossbauer experiment in a rotating system, whose performance was stimulated by our recent findings (2008 Phys. Scr. 77 035302) and which consisted of the fact that a correct processing of Kundigs experimental data on the subject gives an appreciable deviation of a relative energy shift ΔE/E between emission and absorption resonant lines from the standard prediction based on the relativistic dilation of time (that is, ΔE/E=−v2/2c2 to the accuracy c−2, where v is the tangential velocity of the absorber of resonant radiation, and c is the velocity of light in vacuum). That is, the Kundig result we have corrected becomes ΔE/E=−k(v2/c2), with k=0.596±0.006 (instead of the result k=0.5003±0.006, originally reported by Kundig). In our own experiment, we carried out measurements for two absorbers with a substantially different isomer shift, which allowed us to make a correction of the Mossbauer data regarding vibrations in the rotor system at various rotational frequencies. As a result, we obtained the overall estimation k=0.68±0.03.

Mini and micro transducers for Mössbauer spectroscopy

Abstract Two transducers with polyamide fibres as suspension brackets are described in this paper. The mini transducer uses barium ferrite magnets and its weight is 360 g, whereas the micro transducer uses SmCo5 magnets and its weight is 36 g. An integral nonlinearity of the velocity scale better than 0.07% was obtained in experiments with the mini transducer and 0.11% with the micro transducer. Both transducers have been in use since 1992.

Electromagnetic force on a moving dipole

We analyse the force acting on a moving dipole due to an external electromagnetic field and show that the expression derived in Vekstein (1997 Eur. J. Phys. 18 113) is erroneous and suggest the correct equation for the description of this force. We also discuss the physical meaning of the relativistic transformation of current for a closed circuit and carry out the analysis of a number of particular physical problems, which are important from the educational viewpoint.

COMPARISON OF THE PRODUCTIVITY OF FAST DETECTORS FOR MOSSBAUER SPECTROSCOPY

A traditional scintillation detector with NaI(Tl) crystal, proportional counter and a new scintillation detector using YAlO3(Ce) crystal and resonant scintillation detector are compared from the point of their productivity for transmission Mossbauer experiments.

High-performance transmission Mössbauer spectroscopy with YAlO3:Ce scintillation detector

Abstract Some traditional and new types of the detectors are compared from the point of view of their productivity for transmission Mossbauer measurements. The considerable advantage of a scintillation detector with a YAlO 3 : Ce crystal is shown. The results of comparative measurements are given.

TORQUE ON A MOVING ELECTRIC/MAGNETIC DIPOLE

We derive an expression for the torque exerted on an electric/magnetic dipole moving in an electromagnetic fleld, which contains two new velocity-dependent terms that to our knowledge were not reported before. A physical meaning of various torque components is discussed in terms of Lorentz force law and hidden momentum contribution.

Large Volume CaMoO

Several scintillation CaMoO4 crystals with size up to 28times28times220 mm3 were grown by the Czochralski method. Their scintillation properties have been evaluated. Light yield of full size crystals measured with a XP2020 PMT is about 4% relative to a small reference CsI(Tl) crystal. Radio luminescence spectrum under gamma-excitation contains single emission peak with maximum at 520 nm. Optical transmission spectra contain a weak absorption band around 420 nm, which has almost no influence on scintillation light. This allows to produce even larger scintillation elements without deteriorating the light yield. Scintillation kinetics was measured under gamma- and alpha-particle excitation both in fast (2000 ns) and slow (200 mus) time scales. Fast components - 12 ns, (0.1%); 200 ns (0.5%) were detected along with slow - 3.8 mus (3.4%); 20 mus (96%) - components. Difference in fast component contribution under gamma and alpha excitation allows to implement pulse-shape discrimination of alpha-radioactive background coming from impurities in the crystals.

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In this paper we pay attention to the inconsistency in the derivation of the symmetric electromagnetic energy–momentum tensor for a system of charged particles from its canonical form, when the homogeneous Maxwell’s equations are applied to the symmetrizing gauge transformation, while the non-homogeneous Maxwell’s equations are used to obtain the motional equation. Applying the appropriate non-homogeneous Maxwell’s equations to both operations, we obtained an additional symmetric term in the tensor, named as “compensating term”. Analyzing the structure of this “compensating term”, we suggested a method of “gauge renormalization”, which allows transforming the divergent terms of classical electrodynamics (infinite self-force, self-energy and self-momentum) to converging integrals. The motional equation obtained for a non-radiating charged particle does not contain its self-force, and the mass parameter includes the sum of mechanical and electromagnetic masses. The motional equation for a radiating particle also contains the sum of mechanical and electromagnetic masses, and does not yield any “runaway solutions”. It has been shown that the energy flux in a free electromagnetic field is guided by the Poynting vector, whereas the energy flux in a bound EM field is described by the generalized Umov’s vector, defined in the paper. The problem of electromagnetic momentum is also examined.

Scintillation Crystals

We offer a novel method which lets us derive the same classical result for the precession of the perihelion of a planet due to the gravitational effects of the host star. The theoretical approach suggested earlier by the first author is erected upon just the energy conservation law, which consequently yields the weak equivalence principle. The precession outcome is exactly the same as that formulated by the General Theory of Relativity (GTR) for Mercurial orbit eccentricities, but the methodology used is totally different. In our approach, there is no need to make any categorical distinction between luminal and sub-luminal matter, since, as we have previously demonstrated, our theory of gravity is fully compatible with the foundations of quantum mechanics. Our approach can immediately be generalized to the many-body problem, which is otherwise practically impossible within the framework of GTR. Our approach thus leads to a unified description of the micro and macro world physics.