scholarly journals Экспериментальное исследование влияния магнитного поля удлиненного соленоида на растяжение металлических кумулятивных струй

2020 ◽  
Vol 90 (4) ◽  
pp. 637
Author(s):  
С.В. Федоров ◽  
А.В. Бабкин ◽  
В.М. Маринин

Results of the experimental study of the long solenoid longitudinal magnetic field influence on stretching of metal shaped-charge jets in the free flight are presented. Shaped charges with a diameter of 50 mm with copper conic liner were used in experiments. Parameters of the solenoid discharge circuit with the capacitive store of energy were such that the characteristic time moments of magnetic induction maximum achievement made about 100 μs. For the magnetic field parameters realized in experiments with the maximum value of an induction up to 10 T the small increase in depth of steel target penetration was recorded which wasn't exceeding 10 %. The possible reasons of big difference of the received results with the results of similar experiments are discussed.

1980 ◽  
Vol 35 (4) ◽  
pp. 461-463 ◽  
Author(s):  
O. M. Gradov ◽  
L. Stenflo

Abstract A beam of electromagnetic radiation can generate magnetic fields in plasmas. It is shown that those fields grow significantly when the incident radiation is sufficiently strong. We obtain expressions for the characteristic time of the growth of the fields as well as for their spatial distribution and point out a possible mechanism, which can lead to the formation of a quasi-stationary state. The maximum value of the magnetic field strength is estimated


2014 ◽  
Vol 31 (86(3/2014)) ◽  
pp. 425-432 ◽  
Author(s):  
Łukasz Pleskacz ◽  
Elżbieta Fornalik-Wajs ◽  
Aleksandra Roszko

2000 ◽  
Vol 175 ◽  
pp. 324-329 ◽  
Author(s):  
H.F. Henrichs ◽  
J.A. de Jong ◽  
J.-F. Donati ◽  
C. Catala ◽  
G.A. Wade ◽  
...  

AbstractNew circular spectropolarimetric observations of the B1 IIIe star β Cep (υsini = 25 km s−1) show a sinusoidally varying weak longitudinal magnetic field (~ 200 G peak-to-peak). The period corresponds to the 12 day period in the stellar wind variations observed in ultraviolet spectral lines. Maximum field occurs at maximum emission in the UV wind lines. This gives compelling evidence for a magnetic-rotator model for this star, with an unambiguous rotation period of 12 days.The similarity between the Hα emission phases in β Cep and in Be stars suggests that the origin of the Be phenomenon does not have to be rapid rotation: we propose that in β Cep the velocity to bring material in (Keplerian) orbit is provided by the high corotation velocity at the Alfvén radius (~10 R*), whereas in Be stars this is done by the rapid rotation of the surface. In both cases the cause of the emission phases has still to be found. Weak temporary magnetic fields remain the strongest candidate.A full paper, with results including additional measurements in June and July 1999, will appear in A & A.


2019 ◽  
Vol 484 (4) ◽  
pp. 4495-4506 ◽  
Author(s):  
S Hubrig ◽  
M Küker ◽  
S P Järvinen ◽  
A F Kholtygin ◽  
M Schöller ◽  
...  

Abstract Only 11 O-type stars have been confirmed to possess large-scale organized magnetic fields. The presence of a −600 G longitudinal magnetic field in the O9.7 V star HD 54879 with a lower limit of the dipole strength of ∼2 kG was discovered a few years ago in the framework of the ESO large program ‘B-fields in OB stars’. Our FORS 2 spectropolarimetric observations from 2017 October 4 to 2018 February 21 reveal the presence of short- and long-term spectral variability and a gradual magnetic field decrease from about −300 G down to about −90 G. Different scenarios are discussed in an attempt to interpret our observations. Our FORS 2 radial velocity measurements indicate that HD 54879 is a member of a long-period binary.


2014 ◽  
Vol 605 ◽  
pp. 629-632 ◽  
Author(s):  
N. Hadjigeorgiou

Magnetic sensors offer many essential benefits: they enable contactless and thus without wear measurement of mechanical amounts of such as the rotation angle and angular velocity. And are a powerful and economical solution. In this work became a successful attempt to detect and record the noise of a Anisotropic Magnetoresistors (AMR) sensor, hte HMC2003, which manufactured by Honeywell Inc. was tested for its ability to detect the magnetic field and as well as how the corruption, which are involved due to the noise.


1990 ◽  
Vol 157 (1) ◽  
pp. 417-424 ◽  
Author(s):  
L. S. Brizhik ◽  
A. S. Davydov ◽  
V. N. Ermakov

2018 ◽  
Vol 96 (5) ◽  
pp. 519-523 ◽  
Author(s):  
K. Kabin ◽  
G. Kalugin ◽  
E. Spanswick ◽  
E. Donovan

In this paper we discuss conditions under which charged particles are confined by an axisymmetric longitudinal magnetic field with power law dependence on the radius. We derive a transcendental equation for the critical speed corresponding to the threshold between bounded and unbounded trajectories of the particles. This threshold speed shows strong dependence on the direction, and this dependence becomes more prominent as the exponent of the power law increases. The equation for threshold speed can be solved exactly for several specific values of the power exponent, but in general it requires a numerical treatment. Remarkably, if the magnetic field magnitude decreases more slowly than the inverse of the radius, charged particles remain confined no matter how large their energies may be.


2013 ◽  
Vol 9 (S302) ◽  
pp. 402-403
Author(s):  
J. Ramírez Vélez ◽  
D. Hiriart ◽  
G. Valyavin ◽  
J. Valdez ◽  
F. Quiroz ◽  
...  

AbstractWe present the preliminary results of the measurements of longitudinal magnetic field of the massive white dwarf 1658+441. This star have an hydrogen pure atmosphere (e.g. Dupuis & Chayer, 2003). We have observed the target in a total of 18 hrs during 3 consecutive nights in June 2010 and one more in May 2011. The data was acquired with a prototypical spectropolarimeter at the San Pedro Martir Telescope in Mexico. We have tested the magnetic field measurements with our instrument using the famous Babcock's star obtaining consistent results with previous studies. For our object of study, the WD 1658+441, we have measured variable intensities of the longitudinal magnetic field of Blong = 720 kG that oscillates with an amplitude of 130 kG.


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