Electromagnetic fields of relativistic charged particles have a broad frequency spectrum and a sophisticated spatial structure. Field lines offer a visual representation of this spatial structure. In ...this article, we derive a general set of equations for the field lines of any moving charged particle. The electric field lines are completely determined by the unit vector from the retarding point to the observation point. After proper transformations, the field line equations describe the rotation of this vector with an angular velocity coinciding with Thomas precession. In some cases, including all planar trajectories, the field line equations reduce to linear differential equations with constant coefficients. We present a detailed derivation of these equations and their general analytical solution. We then illustrate this method by constructing field lines for the “figure eight” motion of an electric charge moving under the influence of a plane wave, including complex field lines in three dimensions.
Development of a new type of vibrating wire monitor (VWM), which has two mechanically coupled wires (vibrating and target), is presented. The new monitor has a much larger aperture size than the ...previous model of the VWM, and thus allows us to measure transverse beam halos more effectively. A prototype of such a large aperture VWM with a target wire length of 60 mm was designed, manufactured, and bench-tested. Initial beam measurements have been performed at the Fermilab High Intensity Neutrino Source facility, and key results are presented.
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Thermal neutron flux monitors based on vibrating wire Arutunian, S.G.; Bergoz, J.; Chung, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2015, Volume:
797
Journal Article
Peer reviewed
Open access
Two types of neutron monitors with fine spatial resolutions are proposed based on vibrating wires. In the first type, neutrons interact with a vibrating wire, heat it, and lead to the change of its ...natural frequency, which can be precisely measured. To increase the heat deposition during the neutron scattering, the use of gadolinium layer that has the highest thermal neutron capture cross-section among all elements is proposed. The second type uses the vibrating wire as a “resonant target.” Besides the measurement of beam profile according to the average signal, the differential signal synchronized with the wire oscillations defines the beam profile gradient. The monitor׳s spatial resolution is defined by the wire׳s diameter.
The vibrating wire monitors are used for measuring transverse pro-files of radiation beams of different nature. For increasing the accuracy of scanning, and in some cases escaping the scanning ...procedure (measurement of the beam profile using a matrix of wires), it is proposed to use several vibrating wires. A monitor of this kind with two vibrating wires spaced apart at some distance formed the measuring unit of the laboratory stand, developed by us for training students in accelerator technology. The features of such a two-wire monitor and, in particular, the problem of laser radiation power redistribution between the wires are discussed.
Gas Flowmeter Based on Vibrating Wires Aginian, M. A.; Arutunian, S. G.; Harutyunyan, G. S. ...
Journal of contemporary physics,
03/2022, Volume:
57, Issue:
1
Journal Article
Peer reviewed
Open access
The paper proposes a new type of gas flowmeters based on measurements of the deformations of the thermal field of the heater in the presence of a flow using vibrating wires. The advantage of such ...flowmeters as compared with the known ones using a similar thermal principle of operation is the improved accuracy of temperature measurements compared to resistance thermometers or thermocouples. The use of thin wires can also increase the speed of flowmeters. The use of wires 20–30 mm long allows the creation of wide-aperture inlet holes for gas streams. A natural property of the developed flowmeters is also in their bidirectionality. A sample of a flowmeter based on vibrating wires was made and the calibration experiments were carried out. An experiment was carried out in which a flowmeter was used to measure the acceleration.
The paper presents the results of the first experiments on measuring the horizontal and vertical profiles of the proton beam of the C18 cyclotron using a profiling station based on vibrating wire ...monitors. The measurements were performed at the proton beam exit into the air from a special vacuum window located at the end of the cyclotron beam guide. The profiles were measured for different values of proton beam current. The station showed its operability under the conditions of strong disturbances caused by the exposure of protective lead plates to the proton beam.
A new method for fast transverse beam profiling, where a vibrating wire is served as a resonant target, has been developed. The speed of scan up to a few hundred mm/s provides opportunity to make a ...set of beam profiles at different directions of the scan within a reasonable measurement time. This profile set allows us to reconstruct 2D beam profile by filtered back-projection algorithm. The new method may be applied for proton, X-ray, gamma, and neutron beams, and can also be of interest in tomography including medical applications. The method has been tested experimentally by means of laser beams.
The work is devoted to the study of scanning the transverse profile of a beam using a vibrating wire. A new algorithm has been developed that allows the use of a resonant vibrating target method for ...high scanning speeds. The method is based on the idea of measuring secondary/reflected particles/radiation generated from the interaction of the beam particles with the wire material, synchronously with the frequency of the wire oscillation. The proposed algorithm for using a differential signal with sign inversion on consecutive measurements from half-periods of wire oscillations is generalized for the case when the scanning speed is much higher than the average speed of the wire oscillation.
For measuring laser beam profiles, a vibrating wire monitor (VWM) has been introduced. The measurements were carried out at different speeds of scan. Preliminary estimates were made for the ...calculation of the VWM response times with respect to the thermal losses along the wire, and radiative and convective losses. These estimates, however, do not determine the difference between the beam profile and the frequency response of the VWM for a given scan rate. To evaluate the reliability of the frequency response of the VWM, comparisons between forward and reverse beam scans at different speeds have been used. The results of these scans are used to correct the thermal inertia in the frequency response of the VWM.
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