An experimental investigation into the behaviour of a spherical plasma resonance probe in a magnetic field

1967 ◽  
Vol 1 (4) ◽  
pp. 451-462
Author(s):  
P. G. Davies
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Discharge Current ◽  
Plasma Source ◽  
Simplified Model ◽  
Main Peak ◽  
Electron Current ◽  
Plasma Probe ◽  
Spherical Plasma ◽  
The Magnetic Field

The rectified electron current to a non-magnetic and to a magnetic spherical plasma probe has been investigated as a function of the frequency of the applied alternating potential, the discharge current in the plasma source and the magnitude of the magnetic field produced by a Helmholtz coil pair. The frequency at the main peak in the rectified current was found to be always greater than the gyro- frequency and to lie within a range of frequency predicted by Crawford from an analysis of a simplified model. The results of this laboratory work have been applied to a rocket-borne experiment on resonance rectification previously carried out by R.S.R.S.

An experimental investigation of current production by means of rotating magnetic fields

1981 ◽  
Vol 26 (3) ◽  
pp. 465-480 ◽  
Author(s):  
W. N. Hugrass ◽  
I. R. Jones ◽  
M. G. R. Phillips
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Threshold Value ◽  
Rotating Magnetic Field ◽  
Electron Current ◽  
Rotating Magnetic Fields ◽  
Theta Pinch ◽  
Current Production ◽  
Made In ◽  
Rotating Field

An investigation of current production by means of a rotating magnetic field is made in an experiment in which the technique is used to generate a theta-pinch- like distribution of field and plasma. Detailed measurements are made of both the generated unidirectional azimuthal electron current and the penetration of the rotating field into the plasma. The experimental results support the theoretical prediction that a threshold value of the amplitude of the applied rotating field exists for setting the electrons into rotation.

scholarly journals Investigation of mixing time in liquid under influence of rotating magnetic field

2017 ◽  
Vol 38 (4) ◽  
pp. 555-565
Author(s):  
Alicja Przybył ◽  
Rafał Rakoczy ◽  
Maciej Konopacki ◽  
Marian Kordas ◽  
Radosław Drozd ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Mixing Time ◽  
Rotating Magnetic Field ◽  
Homogenization Time ◽  
Set Up ◽  
The Relationship ◽  
The Magnetic Field

Abstract The aim of the study was to present an experimental investigation of the influence of the RMF on mixing time. The obtained results suggest that the homogenization time for the tested experimental set-up depending on the frequency of the RMF can be worked out by means of the relationship between the dimensionless mixing time number and the Reynolds number. It was shown that the magnetic field can be applied successfully to mixing liquids.

Experimental Investigation into the Effect of a Magnetic Field on Magnetorheological Fluids under an Impact Load

2012 ◽  
Vol 721 ◽  
pp. 179-184
Author(s):  
Ahmad Isnikurniawan ◽  
Yoshitaka Moroka ◽  
Hiromichi Ohba ◽  
Tatsuo Sawada
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Qualitative Analysis ◽  
Apparent Viscosity ◽  
Impact Load ◽  
Magnetorheological Fluids ◽  
Mr Fluids ◽  
Experimental Apparatus ◽  
The Impact ◽  
The Magnetic Field

The apparent viscosity of magnetorheological (MR) fluids changes in the presence of a magnetic field. The stronger the magnetic field applied, the more the apparent viscosity increases. An increase in the apparent viscosity increases the restriction on the flow of MR fluids. In this study, we perform a qualitative analysis to investigate the effect of a magnetic field on MR fluids under an impact load. An experimental apparatus that consists of a drop-test tower was developed to simulate the impact load, and an MR fluid in a U-pipe was subjected to the impact load via a piston rod. In the experiment, we measured the displacement and velocity of the piston rod. On the basis of the results, the influence of a given magnetic field on the behavior of MR fluids under an impact load is discussed.

Experimental Investigation of the Transient Behavior of MR Fluids

2011 ◽  
Author(s):  
Ju¨rgen Maas ◽  
Dirk Gu¨th
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Response Time ◽  
Dynamic Properties ◽  
Transient Behavior ◽  
Current Control ◽  
Large Signal ◽  
Carrier Fluid ◽  
Mr Fluids ◽  
The Magnetic Field

The transient behavior of MRF actuators is an important property for certain applications that is mainly affected by three delays, occurring from the dynamic properties of the coil current, the magnetic field and the torque generation by the MRF. In order to investigate the transient behavior of the generated torque with respect to the magnetic field, which is mainly affected by the motion of the MR particles in the carrier fluid, the mentioned response time of the electrical and magnetic domains must be in an appropriated ratio in comparison to the MRF response time to obtain reliable results by experiments. Therefore a special disc-type test actuator with outstanding dynamics is designed that minimizes the delays by the use of an ultrafast current control and a magnetic core made of soft ferrite material for preventing the effects of eddy currents. For the experimental investigation of the transient behavior of MR fluids, the small signal as well as the large signal behavior is analyzed for different test signals and load conditions of the actuator. Various results of the investigated transient behavior are shown finally for two different MR fluids featuring response times of about 1 ms for the fluid itself and switching times of about 4 ms for the MRF actuator.

Characterization of an Analytical Theta-Pinch Plasma Generated with a Unidirectional Capacitive Discharge

1988 ◽  
Vol 42 (1) ◽  
pp. 77-83 ◽  
Author(s):  
E. T. Johnson ◽  
R. D. Sacks
Keyword(s):  
Magnetic Field ◽  
Discharge Current ◽  
Discharge Circuit ◽  
Radiative Properties ◽  
Plasma Properties ◽  
Capacitive Discharge ◽  
Zero Crossings ◽  
Theta Pinch ◽  
The Magnetic Field

The plasma produced by a high-current capacitive discharge through a graphite fiber bundle is compressed by a magnetic field coaxial with the plasma. The magnetic field is generated by the plasma current in a large coil surrounding the plasma. The field induces an azimuthal (theta) current in the plasma. This current couples with the external magnetic field and produces a radial Lorentz force which reduces the rate of plasma expansion. A diode shunt in the capacitive discharge circuit is used for the generation of a unidirectional discharge current. This arrangement eliminates zero-crossings of the discharge current and thus increases the effectiveness of the magnetic field in controlling the radiative properties of the plasma. Design features of the discharge circuit are presented, as well as a comparison of the plasma properties with oscillatory and unidirectional discharge current waveforms.

Experimental investigation of the propagation properties of an edge fluctuation in the KT-5C tokamak

1997 ◽  
Vol 58 (4) ◽  
pp. 601-612 ◽  
Author(s):  
ZHAI KAN ◽  
XU YU-HONG ◽  
WEN YI-ZHI ◽  
YU CHANG-XUAN ◽  
LIU WAN-DONG ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Magnetic Field Line ◽  
Langmuir Probe ◽  
Density Fluctuation ◽  
Electron Density Fluctuation ◽  
Directional Motion ◽  
Propagation Properties ◽  
The Magnetic Field ◽  
Good Agreement

It is found on the KT-5C tokamak that an edge fluctuation can be excited using a pair of floating Langmuir-probe pins. This fluctuation propagates along the magnetic field, with its amplitude decreasing drastically when it is off the magnetic field line, which is similar to the results obtained from experiments on the TEXT tokamak. Moreover, our experimental observations indicate that the excited fluctuation propagates with the electron directional motion, and is mainly manifested in an electron density fluctuation. Physically, this excited fluctuation could be considered as modulation of the external electric field by electrons, and is carried by the electron directional motion wherever it goes. These results are in good agreement with the proposed ballistic model that can be derived by solving the linearized Vlasov equation.

scholarly journals Calculation and optimization of topology of a radial insulating magnetic field in an acceleration gap of a high-power ion diode with an induction plasma source

2016 ◽  
Vol 34 (2) ◽  
pp. 352-355 ◽  
Author(s):  
A.V. Petrov ◽  
G.E. Remnev ◽  
S.K. Pavlov ◽  
I.D. Rumyantsev
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radial Distribution ◽  
High Power ◽  
Magnetic System ◽  
Plasma Source ◽  
Induction Plasma ◽  
Diode System ◽  
Magnetic Diode ◽  
The Magnetic Field

AbstractThe paper presents the results of calculation and optimization of a structure of a radial insulating magnetic field in an acceleration gap of a high-power ion diode. A diode configuration with an induction plasma source and an anode configuration with azimuthally symmetrical slots and a pair of cathode coils of a magnetic diode system have been studied. When the size of the slots is ≤5 mm and codirectional magnetic fields of a diode and shock induction coil, the perturbation of the B-field does not exceed ≤20% and is located in the region near the anode. In this condition, the topology of the magnetic field В = f(1/r) is maintained in the acceleration gap. It was shown that the required radial distribution of the B-field can be optimized by varying the anode profile in the region opposite to two cathode coils of the diode magnetic system.

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