Measurement and Control of the Magnetic Field in a Beta Spectrometer

1964 ◽  
Vol 35 (8) ◽  
pp. 1072-1072 ◽  
Author(s):  
A. A. Bartlett ◽  
Howard Shafer ◽  
J. R. Keith
Keyword(s):  
Magnetic Field ◽  
Beta Spectrometer ◽  
And Control ◽  
Measurement And Control ◽  
The Magnetic Field

In Search of the Jerk Element

2021 ◽  
Author(s):  
Zachary P. Belyaev ◽  
Samuel N. Downes ◽  
Philip A. Voglewede
Keyword(s):  
Magnetic Field ◽  
Motion Planning ◽  
System Performance ◽  
Theoretical Background ◽  
Physical Parameters ◽  
Common Elements ◽  
Planning And Control ◽  
Magneto Rheological ◽  
And Control ◽  
The Magnetic Field

Abstract Mechanical components, such as springs, dampers and mass, alter and influence an engineered system’s motion based upon a system’s position, velocity and acceleration, respectively. This paper aims to discover and develop another element (dubbed the damper) which provides a force proportional to a system’s jerk (i.e., the derivative of acceleration) to better engineer a system’s response. By utilizing the known applications of jerk in motion planning and control theory, existing possible physical implementations and uses of jerk and the jerk element are discussed in relation to its influence on the system’s response, specifically vibration. Using a Buckingham Pi approach, the theoretical background of the jerk element is presented and possible physical parameters are combined to show how the jerk element could be created from common elements and parameters. The most promising approach of varying the magnetic field of existing magneto-rheological dampers is developed to give an example of the jerk element along with the difficulties and concerns in developing the jerk element. This paper serves less of a purpose towards answering all questions of the jerk element, but rather focuses more on posing the appropriate questions which sets the stage for an easily realizable future jerk element which can improve system performance.

Tokamak divertor maps

1994 ◽  
Vol 52 (1) ◽  
pp. 91-111 ◽  
Author(s):  
Alkesh Punjabi ◽  
Arun Verma ◽  
Allen Boozer
Keyword(s):  
Magnetic Field ◽  
Particle Motion ◽  
Mapping Method ◽  
Elegant Method ◽  
Heat Deposition ◽  
System Maps ◽  
Field Lines ◽  
Rotational Transform ◽  
And Control ◽  
The Magnetic Field

A mapping method is developed to investigate the problem of determination and control of heat-deposition patterns on the plates of a tokamak divertor. The deposition pattern is largely determined by the magnetic field lines, which are mathematically equivalent to the trajectories of a single-degree-of-freedom time-dependent Hamiltonian system. Maps are natural tools to study the generic features of such systems. The general theory of maps is presented, and methods for incorporating various features of the magnetic field and particle motion in divertor tokamaks are given. Features of the magnetic field include the profile of the rotational transform, single- versus double-null divertor, reverse map, the effects of naturally occurring low M and N, and externally imposed high-M, high-N perturbations. Particle motion includes radial diffusion, pitch angle and energy scattering, and the electric sheath at the plate. The method is illustrated by calculating the stochastic broadening in a single- null divertor tokamak. Maps provide an efficient, economic and elegant method to study the problem of motion of plasma particles in the stochastic scrape-off layer.

scholarly journals MEASUREMENT IN CONTROL AND DISCRIMINATION OF ENTANGLED PAIRS UNDER SELF-DISTORTION

2011 ◽  
Vol 09 (supp01) ◽  
pp. 165-179
Author(s):  
FRANCISCO DELGADO
Keyword(s):  
Magnetic Field ◽  
Quantum Correlations ◽  
Inhomogeneous Magnetic Field ◽  
Original State ◽  
Communication Processes ◽  
Local Measurements ◽  
Non Local ◽  
And Behavior ◽  
And Control ◽  
Measurement And Control

Quantum correlations and entanglement are fundamental resources for quantum information and quantum communication processes. Developments in these fields normally assume stable resources, not susceptible of distortion. That is not always the case, Heisenberg interactions between qubits can produce distortion on entangled pairs generated for engineering purposes (e. g. quantum computation or quantum cryptography). The presence of parasite magnetic fields modifies the expected properties and behavior for which the pair was intended. Quantum measurement and control help to discriminate the original state in order to correct it or reconstruct it using some procedures which do not alter their quantum nature. Different kinds of quantum entangled pairs driven by a Heisenberg Hamiltonian with an additional inhomogeneous magnetic field become distorted. They can be reconstructed by adding an external magnetic field with fidelity close to one. In addition, each state can be efficiently discriminated. Combining both processes, first reconstruction without discrimination and after discrimination with adequate non-local measurements, it is possible to (a) improve the discrimination, and (b) reprepare faithfully the original state. The complete process gives fidelities better than 0.9. Some results about a class of equivalence for the required measurements are found, allowing to select the experimentally most adequate.

scholarly journals Nd-Fe-B MAGNETS UNDER ELECTRON IRRADIATION WITH THE ENERGY OF 23 MeV

2020 ◽  
pp. 23-27
Author(s):  
V.A. Bovda ◽  
А.М. Bovda ◽  
I.S. Guk ◽  
A.N. Dovbnya ◽  
V.N. Lyashchenko ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Magnetic Flux ◽  
Electron Irradiation ◽  
Reference Sample ◽  
Absorbed Dose ◽  
Initial State ◽  
Magnetic Performance ◽  
And Control ◽  
The Magnetic Field

Four Nd-Fe-B magnets underwent irradiation under 23 MeV electron beam. Nd-Fe-B magnets were magnetized to the technical saturation in the magnetic field of 3.5 T before electron treatment. Two Nd-Fe-B samples (1 and 2) were exposed to the direct electron beam with the energy of 23 MeV. Sample 2 was shielded by tungsten converter. The thickness of the tungsten converter was 4.72 mm. The absorbed dose for the samples was 16 GRad. Sample 3 was subjected to bremsstrahlung of electron irradiation with the energy of 23 MeV. Sample 4 was used as a reference sample for calibration and control measurements. While magnetic flux of sample under direct electron beam of 23 MeV was changed significantly, sample 2 showed the change of magnetic flux to a less degree. Magnetic performance of sample 3 corresponded closely to the initial state.

scholarly journals Detailed airborne geophysical survey of complexly dislocated strata in the Sutam terrane (Aldan shield) during studies of iron-ore deposits

2020 ◽  
Vol 11 (1) ◽  
pp. 141-150 ◽  
Author(s):  
A. A. Syasko ◽  
N. N. Grib ◽  
V. S. Imaev ◽  
L. P. Imaeva ◽  
I. I. Kolodeznikov
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Survey Data ◽  
Iron Ore ◽  
Ore Deposits ◽  
Aeromagnetic Survey ◽  
Geophysical Surveys ◽  
Iron Ore Deposits ◽  
And Control ◽  
The Magnetic Field

Magnetic exploration is the most informational and economical method of prospecting and exploration of iron-ore deposits. In rough-terrain and remote areas without any infrastructure, problems associated with ground-based methods can be avoided by using modern unmanned technologies that allow conducting geophysical surveys in a more efficient way. An unmanned aeromagnetic survey complex (aerial vehicle, UAV) Geoscan 401 was used to assess the possibility of using UAVs for aeromagnetic surveying of iron-ore deposits. Our experimental study was conducted in the well-studied area of the largest iron-ore deposit of South Yakutia. The UAV capacities were confirmed by comparing the aeromagnetic survey data with the available data obtained by ground magnetic exploration of the study area. By analysing magnetic fields, we established that the anomalies detected by the ground and aeromagnetic surveys were fully identical. Furthermore, a weak anomaly was discovered in the northeastern part of the study area (it was not reflected in the magnetic field from the ground survey data). Recalculation of the vertical gradient of the magnetic field shows that the anomaly is caused by a blind ore body. Its upper edge is located at a depth of 200–250 m from the day surface. In calculations for a data array without gradient intervals, a mean square error (MSE) amounts to 1.01 nT. An absolute error in the heights of the working and control flights did not exceed 1.5 m. Both the preliminary and control measurements were performed very efficiently. Profiles for UAV surveys were spaced by 100 m. A 1.0 km2 site was covered by one flight within approximately 20 minutes. The Geoskan-401 UAV is useful for obtaining orthophotos, topographic maps and 3D models of the surveyed territory as required for further studies consistent with the magnetic surveys. The aeromagnetic surveys were followed by trenching to verify the newly discovered anomalies. Based on the results of this experimental study, the forecast resources of the Sutam deposit should be increased by almost 250–350 million tons, i.e. plus 15 % to the previously explored and approved reserves of the Sutam field.

A Magneto-Hydrodynamic Micro Fluidic Network

2002 ◽  
Author(s):  
Haim H. Bau ◽  
Jianzhong Zhu ◽  
Shizhi Qian ◽  
Yu Xiang
Keyword(s):  
Magnetic Field ◽  
Magnetic Material ◽  
Uniform Magnetic Field ◽  
Building Blocks ◽  
Chaotic Advection ◽  
Electrode Pair ◽  
Electric Circuits ◽  
And Control ◽  
The Magnetic Field ◽  
External Uniform Magnetic Field

The magneto hydrodynamic fluidic network’s basic building blocks are conduits equipped with two electrodes positioned on opposing walls. The entire device is either subjected to an external uniform magnetic field or fabricated within a magnetic material. When a prescribed potential difference is applied across each electrode pair, it induces current in the liquid (assumed to be a weakly conductive). The current interacts with the magnetic field to produce a Lorentz force that is perpendicular to both the directions of the current and the magnetic field. Analogously with electric circuits, by judicious application of the potential differences at various branches, one can direct liquid flow in any desired way and rate without a need for mechanical pumps or valves. By equipping the network branches with additional, interior electrodes, the branches double as stirrers capable of generating chaotic advection. The paper describes the basic building blocks for such a network, the operation of these branches as stirrers, a general theory for the analysis and control of fluidic magneto-hydrodynamic networks, and an example of a network fabricated with low temperature, co-fired ceramic tapes.

Research on the Measurement and Control Technology of Controllable Alternating Magnetic Field Generator to Magnetized Breed

2013 ◽  
Vol 303-306 ◽  
pp. 601-606
Author(s):  
Guo Wen Hu ◽  
Li Sheng Zhang ◽  
Lin Wang ◽  
Yin Jie Wang
Keyword(s):  
Magnetic Field ◽  
Control Method ◽  
Magnetic Energy ◽  
Voltage Regulation ◽  
Resonant Circuit ◽  
Magnetic Field Measurement ◽  
Control Technology ◽  
Magnetic Field Generation ◽  
And Control ◽  
Measurement And Control

Controlled and alternating induction magnetic field generation device which induces plant seeds to breed on floor space has been developed. The incentive ferrite induction coil is used in the device to produce induced magnetic field. The common AC-DC-AC topology was adopted for the variable frequency power supply, and AC power inverter circuit adopts SPWM inverter frequency modulation and voltage regulation mode, realizing the sinusoidal VVF. In order to improve the conversion efficiency of system electrical energy to magnetic energy, the RLC series resonant circuit is chosen in the circuit of output magnetic field. Measurement and control system using DSP microcomputer measurement and control technology and digital PID control method. The frequency and intensity of inductive magnetic field in the air gap changes as the changes of current intensity in coils. The experimental study of rice seeds shows that test result is obviously better than traditional biological magnetization induced breeding technique of fixed magnetic poles.

scholarly journals Investigating the n=1 and n=2 error fields in W7-X using the newly accelerated FIELDLINES code

2021 ◽  
Author(s):  
Dion Engels ◽  
Samuel A Lazerson ◽  
Victor Bykov ◽  
Josefine H E Proll
Keyword(s):  
Magnetic Field ◽  
Heat Flux ◽  
Collision Model ◽  
Fusion Device ◽  
Load Asymmetry ◽  
Wall Collision ◽  
Error Field ◽  
Line Diffusion ◽  
And Control ◽  
The Magnetic Field

Abstract No fusion device can be created without any uncertainty; there is always a slight deviation from the geometric specification. These deviations can add up create a deviation of the magnetic field. This deviation is known as the (magnetic) error field. Correcting these error fields is desired as they cause asymmetries in the divertor loads and can thus cause damage to the device if they grow too large. These error fields can be defined by their toroidal (n) and poloidal number (m). The correction of the n = 1 and n = 2 fields in Wendelstein 7-X (W7-X) is investigated in this work. This investigation focuses on field line diffusion to the divertor, a proxy for divertor heat flux. Such work leverages the 25x speedup obtained through the implementation of a new particle-wall collision model. The n = 1 and n = 2 error fields of the as-built coils model of W7-X are corrected by scanning phase and amplitude of the trim and control coils. Reductions in the divertor load asymmetry by factors of four are demonstrated using error field correction. It is found that the as-built coils model has a significantly lower m⁄n = 1⁄1 error field than found in experiments.

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