scholarly journals Metrology techniques for the verification of the alignment of the EU gyrotron prototype for ITER

2019 ◽  
Vol 203 ◽  
pp. 04015
Author(s):  
Francisco Sanchez ◽  
Ferran Albajar ◽  
Alessandro Lo Bue ◽  
Stephano Alberti ◽  
Konstantinos Avramidis ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Pulse Duration ◽  
Short Pulse ◽  
Superconducting Magnet ◽  
Heating System ◽  
Test Facility ◽  
Magnetic Field Axis ◽  
Full Power ◽  
The Magnetic Field ◽  
The Eu

The EU gyrotron for the ITER Electron Cyclotron (EC) heating system has been developed in coordinated efforts of the EGYC Consortium, Thales ED (TED) and Fusion for Energy (F4E) and under the supervision of ITER Organization Central Team. After the successful verification of the design of the 1MW, 170 GHz hollow cylindrical cavity gyrotron operating at the nominal TE32,9 mode with a short pulse gyrotron prototype at KIT, an industrial CW gyrotron prototype was manufactured by TED and tested at ~0.8 MW output power and 180 s pulse duration, which is the limit of the HV power supply currently available at KIT. The experiments are being continued at SPC in 2018 to extend further the pulse duration, taking advantage of the existing CW full-power capabilities of the gyrotron test facility recently upgraded for the FALCON project. The gyrotron cavity interaction is very sensitive to the alignment of the internal mechanical parts of the gyrotron tube with the magnetic field generated by the superconducting magnet within a typical range of 0.2 – 0.5 mm. The control of the tolerances and deformations becomes therefore critical to achieving the target performances. With the EU gyrotron prototype it was possible to adjust the alignment of the gyrotron tube with respect to the magnetic field axis during the installation and commissioning phase. The actual shift and tilt movements were verified using advanced metrology methods such as photogrammetry. In this paper, the alignment control techniques and procedures will be discussed also in view of enhancing the reproducibility of gyrotron performance during series production.

A 3 T superconducting magnet for long-run magnetic Compton-scattering experiments

1998 ◽  
Vol 5 (3) ◽  
pp. 937-939 ◽  
Author(s):  
Nobuhiko Sakai ◽  
Hiroshi Ohkubo ◽  
Yasushi Nakamura
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Compton Scattering ◽  
Superconducting Magnet ◽  
Field Direction ◽  
Compton Profile ◽  
Magnetic Field Direction ◽  
Long Run ◽  
Radiation Shields ◽  
The Magnetic Field

A 3 T superconducting magnet has been designed and constructed for magnetic Compton-profile (MCP) measurements with the new capabilities that the magnetic field direction can be altered quickly (within 5 s) and liquid-He refill is not required for more than one week. For the latter capability, two refrigerators have been directly attached to the cryostat to maintain the low temperature of the radiation shields and for the recondensation of liquid He. The system has been satisfactorily operated for over one week.

scholarly journals Combined laser and magnetic field treatment of YFeO3—containing films grown by spray-pyrolysis

2004 ◽  
Vol 2 (1) ◽  
pp. 188-195
Author(s):  
N. Mihailov ◽  
O. Vankov ◽  
N. Petrova ◽  
D. Kovacheva
Keyword(s):  
Magnetic Field ◽  
Spray Pyrolysis ◽  
Pulse Duration ◽  
Fused Silica ◽  
Crystallite Sizes ◽  
Citric Complexes ◽  
Magnetic Field Treatment ◽  
Glycol Solution ◽  
The Magnetic Field ◽  
Post Deposition

AbstractThin films (50–1200 nm) of YFeO3 were deposited on fused silica substrates by spray-pyrolysis using ethylene glycol solution of Y-Fe(III) citric complexes. The films were post deposition annealed at 750°C in static air for 2 h. Films obtained in this way were afterwards irradiated by a burst mode operated Nd-YAG laser (pulse energy 650 mJ, pulse duration 700 μs, energy density 110 mJ/cm2). The laser’s onset was synchronized with that of a magnetic field pulse of nearly square shape (magnetic induction 0.5 T, pulse duration 900 μs). The samples were placed normally to the direction of the magnetic field. The treatment does not affect the phase composition of the film but significantly increases the crystallite sizes of the phases presenting in the sample. The saturation magnetization of the films decreases as a result of the laser and magnetic field treatment and the coercive force increases by 50%.

A Proposed Experiment of Direct Detecting of the Vector Potential within Classical Electrodynamics

1997 ◽  
Vol 11 (12) ◽  
pp. 531-540
Author(s):  
V. Onoochin
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Charged Particle ◽  
Vector Potential ◽  
Energy Exchange ◽  
Short Pulse ◽  
Classical Electrodynamics ◽  
Direct Influence ◽  
Ultra Short Pulse ◽  
The Magnetic Field

An experiment within the framework of classical electrodynamics is proposed, to demonstrate Boyer's suggestion of a change in the velocity of a charged particle as it passes close to a solenoid. The moving charge is replaced by an ultra-short pulse (USP), whose characteristics should depend on the current in the coil. This dependence results from the exchange of energy between the electromagnetic field of the pulse and the magnetic field within the solenoid. This energy exchange could only be explained, by assuming that the vector potential of the solenoid has a direct influence on the pulse.

Finite Element Analysis of the Magnetic Field Simulation of High Temperature Superconducting Magnet

2014 ◽  
Vol 672-674 ◽  
pp. 562-566
Author(s):  
Ying Hong Luo ◽  
Jing Jing Wang
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Field Distribution ◽  
Magnetic Energy ◽  
Superconducting Magnet ◽  
Magnetic Field Distribution ◽  
Magnetic Storage ◽  
Element Analysis ◽  
The Magnetic Field

Superconducting Magnetic Energy Storage (SMES) system use conductive coils made of superconductor wire to store energy, its application entirely depends on the design and development of superconducting magnet, as the magnetic storage element, during the operation of the superconducting magnet generates relatively strong magnetic field. In this paper, a 1MJ class single solenoidal SMES with Bi2223/Ag conductor is presented. On the basis of electromagnetic theory, subsequently infers mathematical model of magnetic field distribution by ANSYS finite element analysis software, modeling a two-dimensional electromagnetic analysis of 44 double pancakes to get the magnetic field distribution patterns. The results of the analysis provide a reference for the structural design, optimization of a superconducting magnet and shielding of stray magnetic field.

scholarly journals Radiation Beaming in Pulsars

1971 ◽  
Vol 46 ◽  
pp. 455-456
Author(s):  
V. Canuto
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Coming Out ◽  
Critical Magnetic Field ◽  
Zero Field ◽  
Ordinary Wave ◽  
Magnetic Field Axis ◽  
Field Lines ◽  
Star Surface ◽  
The Magnetic Field

It is usually considered that the beaming of the radiation coming out of a pulsar has to be strictly connected with the mechanism producing the radiation itself. We want to show that even when the emitting mechanism gives rise to an isotropically distributed radiation, the presence of a strong magnetic field will automatically beam the radiation preferentially along the magnetic field line rather than in any other direction. We have computed the Compton scattering and from that the opacity KH (K0 is the opacity for zero field). In Figure 1 the ratio KH/K0 is given vs. θ, the angle between the propagation vector and the magnetic field axis. Hq is a critical magnetic field numerically equal to 4.41 × 1013 G; Ne is the electron density. For the ordinary wave the opacity is reduced at θ = 0, while it is unaffected at θ = π/2 where KH → K0. Even at θ = π/4 the ratio KH/K0 is still ≃ 10−2, and a good beaming is still present. The values of the parameters are proper for a neutron star surface. It is to be noticed that the ratio KH/K0 is of the order of (ω/ωH)2 or [(kT/mc2)/(H/Hq]2. One therefore can conclude that the presence of a magnetic field itself assures the beaming of radiation along the field lines.

Magnetically Tailored Arc and Glow Discharge Plasmas for Atomic Spectroscopy

1987 ◽  
Vol 41 (5) ◽  
pp. 833-843 ◽  
Author(s):  
K. Trivedi ◽  
S. Tanguay ◽  
M. Matties ◽  
R. Sacks
Keyword(s):  
Magnetic Field ◽  
Glow Discharge ◽  
Vertical Displacement ◽  
Atomic Spectroscopy ◽  
Radiative Properties ◽  
Current Channel ◽  
Drift Motion ◽  
Magnetic Field Axis ◽  
Discharge Plasmas ◽  
The Magnetic Field

Three magnetic field-plasma configurations are used to study the interaction of external magnetic fields with analytically useful plasma devices. First, a magnetic field oscillating at 60 Hz and normal to the electric field in a 12-A direct current arc plasma is used to obtain an Ē×B̄ drift motion of the arc current channel. This causes a periodic vertical displacement of the channel. Second, a cw magnetic field is used to alter the structure and radiative properties of a demountable glow discharge lamp that uses a center-post cathode. The magnetic field axis is parallel to the cathode axis, and the lamp is operated in a pseudo-magnetron mode. Third, a damped, oscillatory magnetic field produced by discharging a capacitor through a coil is used to alter the radiative characteristics of several commercial hollow cathode lamps. The magnetic field is parallel to the cathode axis, and again the lamps operate in a pseudo-magnetron mode. In all three systems, the presence of the magnetic field drastically alters the radiative properties of the plasmas.

Observations from the Analyses of Magnetic Field and AC Loss Distributions in the NHMFL 32 T All-Superconducting Magnet HTS Insert

2013 ◽  
Vol 23 (3) ◽  
pp. 4300704-4300704 ◽  
Author(s):  
Andrew Gavrilin ◽  
Jun Lu ◽  
Hongyu Bai ◽  
David Hilton ◽  
W Markiewicz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Superconducting Magnet ◽  
Coated Conductors ◽  
Ac Loss ◽  
Ac Losses ◽  
Magnet System ◽  
Field Gradients ◽  
The Magnetic Field ◽  
Helium Vapor

A 17 T high-temperature superconducting two-coil magnet (insert) to be operated in a 15 T low-temperature superconducting multisection magnet (outsert) is the most demanding part of the National High Magnetic Field Laboratory all-superconducting 32 T magnet system. The HTS coils are of the pancake type and to be wound with REBCO coated conductors/tapes manufactured by SuperPower, Inc. The distribution of AC losses in the HTS windings during the magnet charging/discharging process are computed and analyzed with due regard for the AC loss density dependence on the magnetic field and the field angle. The calculations are based on the measured magnetization of a representative sample against magnetic field and field angle. The results enable determination of heat load on the magnet and its cryogenic system. Since the magnet is of the pool-cooled type, a related helium vapor bubble problem can develop owing to the high field and field gradients, and the diamagnetic susceptibility of helium.

scholarly journals Effect of Magnetic Field and Temperature on the Exchange Bias in Phase-Separated Nd1-xSrxCoO3(x=0.10, 0.15)

2015 ◽  
Vol 9 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Yi-Yun Yang
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Freezing Temperature ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Magnetic Field Axis ◽  
Coexisting Phases ◽  
The Magnetic Field

The exchange bias phenomena of phase-separated Nd1-xSrxCoO3(x=0.10, 0.15) samples were systematically investigated in this paper. The samples were prepared using conventional solid state reaction method. When the NdSrCoO samples cooled down in magnetic field below freezing temperature, the hysteresis loops shifted along the magnetic field axis. Moreover, exchange bias of Nd1-xSrxCoO3 is strongly dependent on the field and the temperature. The influence of magnetic field on the relative ratio of the coexisting phases may be responsible for these behaviors. Therefore, our study confirmed that in phase-separated system, the exchange coupling at the interface between the ferromagnetism clusters and the spin glass regions may induce interfacial exchange anisotropy.

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