Design of a Dynamic Magnetic Field Steered Cathodic Arc Source in Arc Ion Plating

2011 ◽  
Vol 340 ◽  
pp. 167-172 ◽  
Author(s):  
Wen Chang Lang
Keyword(s):  
Magnetic Field ◽  
Cathode Surface ◽  
Target Surface ◽  
Target Thickness ◽  
Current Ratio ◽  
Operating Modes ◽  
Electromagnetic Coils ◽  
Cathodic Arc ◽  
Dynamic Magnetic Field ◽  
The Magnetic Field

In this work, a dynamic arched magnetic field steered arc source was deigned by virtue of Finite Element Method (FEM) calculation. The magnetic field was produced by two main electromagnetic coils so that the magnetic field can be adjusted with the help of the two currentI1and I2,whereI1is the current to the internal coil mounted coaxially in a magnetic yoke generating a static arched magnetic field to confine the cathode spots and I2is the current to the external coil mounted coaxially outside the above yoke adjusting the position of the vertex of arch. Base on the results of simulation, it was found this design enable the sweeping of the arc spots on the target surface by means of adjusting the ratio of current (I1/I2) , and cause the arc distribute evenly on the cathode surface in the diffuse arc mode transferred from the constricted arc mode. The effects of the target thickness and current ratio on the configuration and intensity of dynamic arched magnetic field were investigated. The optimized operating modes was proposed and discussed.

Monte Carlo calculation of the energy parameters and spatial distribution of the cathodic arc ions while passing through the macro-particles filters

2018 ◽  
Vol 1 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Alexey Chernogor ◽  
Igor Blinkov ◽  
Alexey Volkhonskiy
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Monte Carlo ◽  
Monte Carlo Calculation ◽  
Inhomogeneous Magnetic Field ◽  
Flow Energy ◽  
Wide Range ◽  
Field Concentrator ◽  
Cathodic Arc ◽  
The Magnetic Field

The flow, energy distribution and concentrations profiles of Ti ions in cathodic arc are studied by test particle Monte Carlo simulations with considering the mass transfer through the macro-particles filters with inhomogeneous magnetic field. The loss of ions due to their deposition on filter walls was calculated as a function of electric current and number of turns in the coil. The magnetic field concentrator that arises in the bending region of the filters leads to increase the loss of the ions component of cathodic arc. The ions loss up to 80 % of their energy resulted by the paired elastic collisions which correspond to the experimental results. The ion fluxes arriving at the surface of the substrates during planetary rotating of them opposite the evaporators mounted to each other at an angle of 120° characterized by the wide range of mutual overlapping.

scholarly journals The Effect of Magnetic Field Strength and Geometry on the Deposition Rate and Ionized Flux Fraction in the HiPIMS Discharge

Plasma ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 201-221 ◽  
Author(s):  
Hamidreza Hajihoseini ◽  
Martin Čada ◽  
Zdenek Hubička ◽  
Selen Ünaldi ◽  
Michael A. Raadu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Deposition Rate ◽  
Average Power ◽  
Current Mode ◽  
Ionization Probability ◽  
Cathode Voltage ◽  
Peak Current ◽  
Voltage Mode ◽  
Operating Modes ◽  
The Magnetic Field

We explored the effect of magnetic field strength | B | and geometry (degree of balancing) on the deposition rate and ionized flux fraction F flux in dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) when depositing titanium. The HiPIMS discharge was run in two different operating modes. The first one we refer to as “fixed voltage mode” where the cathode voltage was kept fixed at 625 V while the pulse repetition frequency was varied to achieve the desired time average power (300 W). The second mode we refer to as “fixed peak current mode” and was carried out by adjusting the cathode voltage to maintain a fixed peak discharge current and by varying the frequency to achieve the same average power. Our results show that the dcMS deposition rate was weakly sensitive to variations in the magnetic field while the deposition rate during HiPIMS operated in fixed voltage mode changed from 30% to 90% of the dcMS deposition rate as | B | decreased. In contrast, when operating the HiPIMS discharge in fixed peak current mode, the deposition rate increased only slightly with decreasing | B | . In fixed voltage mode, for weaker | B | , the higher was the deposition rate, the lower was the F flux . In the fixed peak current mode, both deposition rate and F flux increased with decreasing | B | . Deposition rate uniformity measurements illustrated that the dcMS deposition uniformity was rather insensitive to changes in | B | while both HiPIMS operating modes were highly sensitive. The HiPIMS deposition rate uniformity could be 10% lower or up to 10% higher than the dcMS deposition rate uniformity depending on | B | and in particular the magnetic field topology. We related the measured quantities, the deposition rate and ionized flux fraction, to the ionization probability α t and the back attraction probability of the sputtered species β t . We showed that the fraction of the ions of the sputtered material that escape back attraction increased by 30% when | B | was reduced during operation in fixed peak current mode while the ionization probability of the sputtered species increased with increasing | B | , due to increased discharge current, when operating in fixed voltage mode.

scholarly journals Ion energy increase in laser-generated plasma expanding through axial magnetic field trap

2007 ◽  
Vol 25 (3) ◽  
pp. 453-464 ◽  
Author(s):  
L. Torrisi ◽  
D. Margarone ◽  
S. Gammino ◽  
L. Andò
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Electric Fields ◽  
Axial Magnetic Field ◽  
Ion Beam ◽  
High Vacuum ◽  
Target Surface ◽  
Axial Direction ◽  
Ion Interactions ◽  
The Magnetic Field

Laser-generated plasma is obtained in high vacuum (10−7 mbar) by irradiation of metallic targets (Al, Cu, Ta) with laser beam with intensities of the order of 1010 W/cm2. An Nd:Yag laser operating at 1064 nm wavelength, 9 ns pulse width, and 500 mJ maximum pulse energy is used. Time of flight measurements of ion emission along the direction normal to the target surface were performed with an ion collector. Measurements with and without a 0.1 Tesla magnetic field, directed along the normal to the target surface, have been taken for different target-detector distances and for increasing laser pulse intensity. Results have demonstrated that the magnetic field configuration creates an electron trap in front of the target surface along the axial direction. Electric fields inside the trap induce ion acceleration; the presence of electron bundles not only focuses the ion beam but also increases its energy, mean charge state and current. The explanation of this phenomenon can be found in the electric field modification inside the non-equilibrium plasma because of an electron bunching that increases the number of electron-ion interactions. The magnetic field, in fact, modifies the electric field due to the charge separation between the clouds of fast electrons, many of which remain trapped in the magnetic hole, and slow ions, ejected from the ablated target; moreover it increases the number of electron-ion interactions producing higher charge states.

scholarly journals Ion charge state and energy enhancement by axial magnetic field applied during laser produced plasma expansion

2016 ◽  
Vol 34 (4) ◽  
pp. 606-614 ◽  
Author(s):  
S.A. Abbasi ◽  
A.H. Dogar ◽  
B. Ilyas ◽  
S. Ullah ◽  
M. Rafique ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Charge State ◽  
Impact Ionization ◽  
Axial Magnetic Field ◽  
Debye Length ◽  
Target Surface ◽  
Laser Wavelength ◽  
Electrostatic Model ◽  
Ion Energy ◽  
The Magnetic Field

AbstractThe effects of axial magnetic field on the properties of the ions ejected from Nd:YAG laser (wavelength = 1064 nm, pulse duration = 6 ns) produced expanding Cu plasma were investigated. A plane Cu target, without and with 0.23 T axial magnetic field at its surface, was irradiated in the fluence range of 2–24 J/cm2. The ions emitted along the target surface normal were analyzed with the help of ion collector and time-of-flight electrostatic ion energy analyzer. The integrated ion yield, highest ion charge state, average ion energy, and energy of individual ion charge states were found to increase by application of the magnetic field. The initial parameters of the non-equilibrium plasma such as average ion charge, equivalent potential, electron temperature, electron density, Debye length, and transient electric field were estimated from the experimental results obtained without and with application of the magnetic field. The increase of ion yield and ion charge state by application of magnetic field are most probably due to the trapping of electrons in front of the target surface, which boosts up the electron impact ionization process. The ion energy increment due to the magnetic field is discussed in the frame work of electrostatic model for ion acceleration in laser plasma.

Enhancement effect of nonferromagnetic particles on the viscosity of magnetorheological fluid under a dynamic magnetic field

2021 ◽  
Vol 14 (06) ◽  
pp. 2151038
Author(s):  
Bingsan Chen ◽  
Cheng Zheng ◽  
Zhongyu Bao ◽  
Chunyu Li ◽  
Dicheng Huang
Keyword(s):  
Magnetic Field ◽  
Glass Powder ◽  
Magnetorheological Fluid ◽  
Calculation Model ◽  
Enhancement Effect ◽  
Sedimentation Resistance ◽  
Powder Content ◽  
Dynamic Magnetic Field ◽  
The Magnetic Field ◽  
Made In

This study aims to investigate the effect of nonferromagnetic particle content on the properties of the magnetorheological fluid (MRF) under a dynamic magnetic field. A magnetic-induced viscosity calculation model under the temperature field was built. The influence on the viscosity of the MRF made in-house was analyzed by adding different proportions of nonferromagnetic particles, such as glass powder. Experiments show that a certain proportion of glass powder can increase the viscosity of the MRF. When the powder content is less than 10%, viscosity increases as the glass powder content increases. Conversely, viscosity decreases as the glass powder content increases when the content is more than 10% but less than 20%. These results indicate that adding micron glass powder to the MRF can increase the magnetic saturation limit of the MRF under the dynamic magnetic field and improve its settlement resistance by 25.6%.When 10% glass powder is added to the MRF containing 60% iron powder, sedimentation resistance increases by 25.6%. When the magnetic field intensity is 640 mT, the viscosity of the MRF increases by 6.6 times.

Study of Magnetic Fields of Magnetron Sputtering Affecting CrN Films

2013 ◽  
Vol 401-403 ◽  
pp. 822-827
Author(s):  
Ming Der Jean ◽  
Maw Tyan Sheen ◽  
Ching Fu Wu ◽  
Feng Ming Chen ◽  
San Jen Lee
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Wear Rate ◽  
Magnetron Sputtering ◽  
Target Surface ◽  
Critical Force ◽  
Magnetic Sputtering ◽  
Magnetic Field Variations ◽  
Hardness Values ◽  
The Magnetic Field

This article presents the distribution of the varying magnetic field and its effect by magnetron sputtering on mechanical properties of CrN films. The magnetic field variations in the sputtering processes were explored, and the strength of magnetic field in the unbalanced magnetic sputtering systems is controlled. In addition, the microstructure, composition and surface properties of CrN films prepared by magnetron sputtering were investigated. At a GDMT of 27mm, the highest wear rate value and hardness values seems to be appeared, while the higher critical force value appears to occur at 49mm GDMT during 18 tests. The experimental results have showed that in the enhancement in overall intensity at the gap distance of 27mm between magnet set and the target surface (GDMT), magnetic field strength varied having a significant influence on the CrN structures was readily noticeable, while the wear scar curve at 49mm GDMT possessed better tribological properties than those of the others. Thus, magnetic field variations play a crucial role in determining the properties of the films

Factors Affecting the Finishing Characteristics of an Internal Magnetic Abrasive Finishing Process for High Purity Fittings

2004 ◽  
Author(s):  
Hitomi Yamaguchi ◽  
Takeo Shinmura ◽  
Megumi Sekine
Keyword(s):  
Magnetic Field ◽  
High Purity ◽  
Target Surface ◽  
Magnetic Abrasive Finishing ◽  
Factors Affecting ◽  
Shaped Tube ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Abrasive Behavior ◽  
The Magnetic Field

In the case of internal finishing of the bent section of a complex shaped tube, such as found in high purity fittings, by a magnetic abrasive finishing process, the magnetic field at the finishing area and, therefore, the finishing force are hardly uniform over the entire finishing area due to the geometry. This affects the abrasive behavior against the inner surface of the bent section, changing the finishing characteristics of SUS304 stainless steel fittings. In practice, non-uniformities in the surface finish remain at the bent section between the inside, outside, and lateral regions. This unevenness combines to cause difficulties in achieving uniform finishing. Magnetic abrasive is generally supplied with ferrous particles, and the ferrous particles experience greater magnetic force and play a role in pressing the magnetic abrasive against the target surface. This paper studies the finishing mechanism in view of the relationship between the magnetic field, the ferrous particles mixed with magnetic abrasive, and the finishing characteristics. The experiments identify the finishing conditions required for successfully diminishing the non-uniformity in the finished surface, and methods are recommended to satisfy the required conditions. The experiments using the proposed methods show the feasibility of producing a uniformly finished mirror surface.

The Active Magnetic Bearing Enables Optimum Control of Machine Vibrations

1985 ◽  
Author(s):  
Helmut Habermann ◽  
Maurice Brunet
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Electronic Control System ◽  
Electromagnetic Coils ◽  
Reaction Forces ◽  
Automatic Balancing ◽  
The Magnetic Field

The active magnetic bearing is based on the use of forces created by a magnetic field to levitate the rotor without mechanical contact between the stationary and moving parts. A ferromagnetic ring fixed on the rotor “floats” in the magnetic field generated by the electromagnets, which are mounted as two sets of opposing pairs. The current is transmitted to the electromagnetic coils through amplifiers. The four electromagnets control the rotor’s position in response to the signals transmitted from the sensors. The rotor is maintained in equilibrium under the control of the electromagnetic forces. Its position is determined by means of sensors which continuously monitor any displacements between rotor and stator through an electronic control system. As in every control system, damping of the loop is provided by means of a phase advance command from one or more differenciating circuits of the position error signal. The vibrations of the rotor and stator of a machine are generated by different forces: - centrifugal forces due to the misalignment between the geometrical axis and the inertial axis of the rotor (unbalance), - reaction forces due to aerodynamical forces on the rotor and stator blades. The active magnetic bearing allows the decrease and in many cases the fully cancelling of effects of these forces i.e. the vibrations of the machine. The inertial forces can be cancelled by shifting the axis of rotation of the rotor from the geometrical axis to the inertial axis (this system is usually called automatic balancing). The reaction forces due to aerodynamical effects can be cancelled by the creation by the magnetic bearings of forces in opposition. The vibrations are measured on the stator by accelerometers, and the signals drive magnetic bearings which generate forces having the same amplitude but in phase opposition. The improvement in vibrations amplitude usually ranges from 20 Db to 40 Db over a large band of frequencies.

The Effects of Magnetic Field on the Deposited Performance of CrN Films by Magnetron Sputtering

2011 ◽  
Vol 311-313 ◽  
pp. 1340-1347
Author(s):  
Ming Der Jean ◽  
Ming Tsong Chou
Keyword(s):  
Magnetic Field ◽  
Wear Rate ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Smooth Surface ◽  
High Hardness ◽  
Target Surface ◽  
Field Distributions ◽  
Magnetic Sputtering ◽  
The Magnetic Field

This paper reports the effects of varying magnetic field strength on CrN films, deposited by a magnetic sputtering process. The strength of magnetic field in unbalanced magnetic sputtering processes is controlled by adjusting the gap distance between the magnet set and the target surface (GDMT). An improvement in overall intensity, at low GDMT, was observed by adjustable magnetic field distributions. In the chamber, it was readily noticeable that varying the magnetic field strength has an influence on the CrN structures. In experiments, at low GDMT, a high hardness value and lower wear rate become visible in the CrN films. In addition, the CrN films formed have a smooth surface with a dense tiny structure and display preferential orientation in the Cr2N(111) and Cr2N(002) planes, whereas CrN films prepared at higher GDMT exhibit more roughness and the CrN (200) plane is evident. Furthermore, the Cr2N (111) (002) plane possessed better tribological properties than that of the CrN(200) plane, where the wear scars show little failures on the coating surface.

Control of Multiple Magnetic Micro Robots

2015 ◽  
Author(s):  
Denise Wong ◽  
Jeremy Wang ◽  
Edward Steager ◽  
Vijay Kumar
Keyword(s):  
Magnetic Field ◽  
Linear System ◽  
Applied Field ◽  
Dimensional System ◽  
One Dimensional ◽  
Electromagnetic Coils ◽  
Micro Robot ◽  
Simulation Results ◽  
Visual Feedback Control ◽  
The Magnetic Field

A magnetic micro robot is a microscopic magnet that is controlled by a system of electromagnetic coils that generate a magnetic field to manipulate the magnetic robot. A major challenge for manipulating multiple magnets at microscale is that the applied field affects the entire workspace, making it difficult to address individual magnets. In this paper, we propose a system where electromagnetic coils are close to the magnets being manipulated to exploit spatial non-uniformities in the magnetic field. Our model considers the magnetic field generated by the electromagnetic coils and the magnetic fields present from neighboring magnetic robots to generate the desired force on each magnet. This approach is demonstrated on a macroscopic, one-dimensional system with two magnets controlled by two electromagnets using visual feedback control. Additionally, simulation results for a linear system with three magnets and three electromagnets are shown. While demonstrated at the macroscale, our results suggest that our methods can be extended for microscale manipulation, where it is advantageous to control multiple identical magnets with global fields.

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