Publications

V.A. Sapunov, A.Yu. Denisov, O.V. Denisova, D.V. Saveliev

Some of the principal experimental and theoretical results concerning metrological parameters of proton and Overhauser magnetometers are studied. In particular, the effect of operating modes, processing algorithms, a sensor design and registration path on the absolute and random errors of geomagnetic field is discussed. The methods of testing and metrological certification used by the laboratory in producing magnetometers are considered in this repot. In particular, simplest laboratory testing, testing by means of special laboratory standard based on a magnetic shield and the certification with a reference magnetometer under conditions of magnetic field standard are described. The measurement systematic error resulted from the thermoelectromotive generated at the polarization or in the presence of temperature gradient is shown for proton and Overhauser sensors. Methods for this defect removal are offered.

This article is on ResearchGate. Open article file.

A.V. Sergeev, A.Yu. Denisov, E.D. Narkhov, A.L. Fedorov, V.A. Sapunov

The article discusses the effect of cylindrical shielding shells on the uniformity of the magnetic field created by coil  sources  used  in  measures  of  low-field  induction.  Calculations  were  carried  out  to  adjust  the  parameters  of  such sources in order to increase the homogeneity of the magnetically shielded system field.

This article is on ResearchGate. Open article file.

V.A. Ushakov, A.Yu. Denisov, A.V. Sergeev, E.D. Narkhov, V.A. Sapunov

This paper presents a hardware-software solution to the problem of studying and controlling the amplitude-time characteristics of the nuclear precession signal of the working substance of the Overhauser sensors of POS-1 magnetometers. The aspects of development are considered: the technical task for the test bench, the hardware design of the device, its general functionality and its software components. Also presented are some results of studies conducted on the stand, demonstrating its efficiency and accuracy.

This article is on ResearchGate. Open article file.

E.D. Narkhov, A.A. Shirokov, A.V. Sergeev, A.L. Fedorov, D.N. Milukov, V.A. Sapunov, A.Yu. Denisov, S.E. Kiselev, V.V. Saveliev, L.A. Muravyev, A.N. Ivanenko

The paper deals with the issues of remote determination of the spatial position of buried pipelines with the help of magnetic survey. This method is economical and does not affect the environment. To achieve the required accuracy of determining the position of the pipelines, it is proposed to use a full gradient multichannel magnetiс system consisting of four Overhauser magnetometers SeaPOS combined with a receiver of a high-precision differential navigation system. Such a configuration of the system makes it possible to accurately determine in space the position of local magnetic anomalies created by pipelines and eliminates the need to take into account the temporal component of the earth’s magnetic field (which isespecially important for the Arctic) by working with spatial field gradients. The problems of the theory of the survey method and technique are considered, algorithms for data processing are proposed and implemented with the aim of solving the problem of high-precision mapping of local magnetic anomalies created by pipelines and solving the inverse magnetiс problem by determining the position and power of the sources of these anomalies.

This article is on ResearchGate. Open article file.

L.A. Muravyev, V.A. Sapunov, E.D. Narkhov, I.M. Khasanov

The sensitivity and resolution of modern geophysical equipment currently directly determines the effectiveness of the application of geophysical methods. The increase in mineral reserves is now often associated with the identification of deposits that had not previously been discovered due to the weak differentiation of search features. Following the terminology of A.A. Nikitin, the object of industrial geophysical research is now increasingly geological low–contrast objects – heterogeneities in the structure of the geological environment, weakly manifested in the fields measured by instruments. The difficulty of studying such objects is due to the fact that measurements take place against a background of interference of various nature.
Magnetometry is one of the most efficient and economical geophysical methods. Examples of objects available for investigation by highly sensitive scalar magnetometers include: spatial inhomogeneities in the upper part of a geological section; deep-lying extended geological bodies of ore type; cultural layer of archaeological sites; artificial magnetic objects. We present the results of using modern nuclear precession magnetometers based on the Processor Overhauser sensor (POS) for the study of indigenous and loose deposits of gold and diamonds in various regions of Russia, as well as in the Republic of Angola.

This article is on ResearchGate. Open article file.

V.A. Sapunov, I.V. Kashin, V.A. Ushakov, A.V. Sergeev, O.V. Denisova

We  present  comprehensive  investigation  of  Overhauser  dynamic  nuclear  polarization  in  solutions  of  the nitroxide radical TANO at high-frequency saturation field of electron paramagnetic resonance transitions with its parallel orientation,  related  to  the  static magnetic  field  up  to  0.1  mT.  Experimental  observation  requires specific  technique  of cycle-polarized application, which is described in detail. It was shown, that these results cannot be interpreted in terms of standard theoretical methods, taking into account the electron magnetic relaxation as conditioned by hyperfine isotropic interaction of NO fragment. We suggest an original description of the effect, based on consideration of the anisotropic hyperfine  interaction,  modulated  by  rotational  diffusion  of  the  NO  fragment.  Thus  developed  theoretical  approach enables to determine the combined contribution of isotropic and anisotropic  interactions and investigate the rotational diffusion process, which can serve as fundamental basis for a new branch of studying regarding molecular diffusion of the spin labels.

This article is on ResearchGate. Open article file.

A. Parshin, A. Budyak, I. Chebokchinov, V. Sapunov, A. Bulnaev, V. Morozov

One of the most real factors of geological exploration optimization is low-altitude Earth remote sensing that includes geophysical prospecting methods. This article describes a case of the efficient application of complex low-altitude UAV-based aerogeophysical surveying during greenfield prospecting for gold in greenfield localized in the Western Sayan mountains (Russia). 90 sq. km site characterized by extremely complicated landscape and terrain conditions as well as controversial views on its geological conditions. Surveys from a multirotor UAV (unmanned aircraft vehicle) were made with terrain flowing and included a simultaneous magnetic and gamma-ray radiometric surveying as well as gamma-ray spectrometry by the ‘static hovering’ method and multispectral photogrammetry. The articles sets forth main principles of the method applied as well as demonstrates the advantages of unmanned aircraft technologies vs. traditional geophysical prospecting methods, i.e. high performance and low costs even in those conditions when ground and aerial surveys are economically impractical or entirely impossible. Application of low-altitude UAV-surveys allowed for a large-scale geological and geophysical mapping involving low costs, for clearing up a controversial point of the site geological conditions and for planning further prospecting, while avoiding erroneous solutions prompted by wrong priori assumptions about a geological structure of the site.

This article is on ResearchGate. Open article file.

L.A. Muravyov, O.A. Kusonsky, P.B. Borodin, V.A. Sapunov, S.E. Kiselev, V.V. Savelyev

We present some development results of the absolute vector proton magnetometer POS-4 based on the switching bias magnetic fields method. Magnetometer POS-4 has a high absolute precision and stability and suitable for geomagnetic observatories and for oil and gas well directional drilling support. We discuss the some basic measurements errors and show the long-term experience in the testing on magnetic observatory Arti (Urals).

This article is on ResearchGate. Open article file.

S. Khomutov, V. Sapunov, A. Denisov, D. Saveliev, I. Babakhanov

The results of measurements by Overhauser vector magnetometer POS-4 carried out for one year and a half are presented. The accuracy, stability and reliability are evaluated.

This article is on ResearchGate. Open article file.

V.A. Sapunov, A.Yu. Denisov, D.V. Savelyev, A.A. Soloviev, S.Yu. Khomutov, P.B. Borodin, E.D. Narkhov, A.V. Sergeev, A.A. Shirokov

This paper covers same results of the research directed at developing an absolute vector proton magnetometer POS-4 based on the switching bias magnetic fields methods. Due to the high absolute precision and stability magnetometer POS-4 found application not only for observatories and to directional drilling support of oi and gas well. Also we discuss the some basic errors of measurements and discuss the long-term experience in the testing of magnetic observatories ART and PARATUNKA.

This article is on ResearchGate. Open article file.

A.V. Sergeev, E.D. Narkhov, A.N. Ivanenko, Yu.V. Brusilovsky, D.N. Milyukov, A.Yu. Denisov, V.A. Sapunov

We tested the full-gradient magnetometer’s system of two ortho oriented Overhauser with a GPS receiver in shallow water. Our investigations show that this is a promising layout prototype of magnetometer measuring complex, designed for high-precision 3D detecting and studying of underwater man-made objects. With such a system, and the existing set of techniques and software we can be able to reliably map and identify anomalies created by such objects, solving the problem of their locations within a small part of meter. 

This article is on ResearchGate. Open article file.

E.D. Narkhov, L.A. Muravyov, A.V. Sergeev, A.L. Fedorov, A.Yu. Denisov, A.A. Shirokov, V.A. Sapunov

Increased sensitivity and resolution of geophysical instruments significantly enhances the effectiveness of non-destructive  investigation  methods  for  standard  geological  problems  and  allows  new  experiments.  We  suggest  to  use modern  highly  sensitive  scalar  magnetometers  for  identification  and  study  of  geological  and  artificial  low-contrast objects in a magnetic field. We present application results of a modern nuclear precession magnetometer POS based on the processor Overhauser sensor. The device is developed and produced by the Quantum Magnetometry Laboratory, Ural Federal  University,  Yekaterinburg,  Russia. Experiments  conducted  in  the  laboratory  and  observatories  allowed  to determine  the  device  absolute  accuracy  of  0.5  nT  and  sensitivity  of  0.02  nT,  and  to confirm  its  operability  in  large magnetic field gradients. This sensitivity is sufficient for detection of magnetic  field changes caused, for example, by tectonomagnetic, seismomagnetic, piezomagnetic effects and electrokinetic phenomena in the geological environment. We  conducted  field  experiments  comparing  POS  magnetometers  metrological  characteristics  with  similar  instruments from Scintrex and Geometrics. The results confirm measurement high stability in long-term observations of the magnetic field change due to geodynamic processes. We tested POS instruments  in  various geophysical  applications, including prospecting and exploration of minerals (placer and ore gold, hydrocarbons, kimberlites); identification of ferromagnetic objects in cover environments; archaeological sites mapping. Our latest experience adds to this list a magnetic survey for pipeline inspection purposes. In addition, we discuss application of a novel absolute 3-component magnetometer POS-4based on a principle of bias field switching  method. The device was tested at several INTERMAGNET  geomagnetic observatories. Due to high absolute accuracy and stability, there is a good prospect of implementing these magnetometers at observation points of long-term geomagnetic field secular variation and in autonomous magnetic observatories.

This article is on ResearchGate. Open article file.