scholarly journals Research on the effect of magnet parameters on the isochronous field of a superconducting cyclotron

2019 ◽  
Vol 34 (3) ◽  
pp. 222-230
Author(s):  
Pengyan Zhou ◽  
Kaizhong Ding ◽  
Junjun Li ◽  
Shiwen Xu ◽  
Yuntao Song
Keyword(s):  
Magnetic Field ◽  
Magnet System ◽  
Magnet Design ◽  
Superconducting Coil ◽  
Superconducting Cyclotron ◽  
Long Time ◽  
Sector Angle ◽  
Spiral Angle ◽  
The Magnetic Field ◽  
Complicated Task

It is a complicated task to obtain an isochronous field of a cyclotron magnet. Due to non-linear property of iron, iterated simulation of magnet design takes a long time to get an isochronous field. As an example, for a magnet design of a 240 MeV (SC240) superconducting cyclotron, the effect of main parameters of a magnet system on the magnetic field was studied, among them the azimuthal sector width, the spiral sector angle, the gap between sectors, the depth of valley region, the position of the coil, the shape of the coil and the excited current of the superconducting coil. It was found that the azimuthal average magnetic field can be increased by any of the following methods, including enlarging azimuthal width, increasing excited current of the superconducting coil, narrowing of the gap between sectors, reducing the depth of the valley region or decreasing the distance between the coil and the mid-plane. In addition, axial oscillation frequency can be improved by increasing the spiral angle, the depth of the valley region, or decreasing the gap between sectors.

DESIGN OF A 300 000-Oe TWO-REGION SOLENOID FOR INTERMITTENT OPERATION

1964 ◽  
Vol 42 (7) ◽  
pp. 1343-1357 ◽  
Author(s):  
Richard Stevenson
Keyword(s):  
Magnetic Field ◽  
Cooling System ◽  
Operating Time ◽  
Maximum Power ◽  
Magnet System ◽  
Total Operating Time ◽  
Helium Gas ◽  
Intermittent Operation ◽  
The Magnetic Field ◽  
Capital Expense

This paper contains a design of an aluminum solenoid magnet system capable of producing a field of 300 000 Oe over a bore of 5.8 cm. The magnetic field is produced by a two-region solenoid operated at 15 °K and cooled by compressed helium gas. Details of the structure are described, and calculations are given for all important parts of the cooling system. The magnet is designed for a total operating time at maximum power of at least 40 minutes in a week. The low capital expense of the system makes it suitable for installation in small laboratories.

scholarly journals Broadband Linear Polarization in Ap Stars

1993 ◽  
Vol 138 ◽  
pp. 305-309
Author(s):  
Marco Landolfi ◽  
Egidio Landi Degl’Innocenti ◽  
Maurizio Landi Degl’Innocenti ◽  
Jean-Louis Leroy ◽  
Stefano Bagnulo
Keyword(s):  
Magnetic Field ◽  
Circular Polarization ◽  
Linear Polarization ◽  
Rotation Axis ◽  
Spectral Lines ◽  
Line Of Sight ◽  
Long Time ◽  
Rotating Star ◽  
Ap Stars ◽  
The Magnetic Field

AbstractBroadband linear polarization in the spectra of Ap stars is believed to be due to differential saturation between σ and π Zeeman components in spectral lines. This mechanism has been known for a long time to be the main agent of a similar phenomenon observed in sunspots. Since this phenomenon has been carefully calibrated in the solar case, it can be confidently used to deduce the magnetic field of Ap stars.Given the magnetic configuration of a rotating star, it is possible to deduce the broadband polarization at any phase. Calculations performed for the oblique dipole model show that the resulting polarization diagrams are very sensitive to the values of i (the angle between the rotation axis and the line of sight) and β (the angle between the rotation and magnetic axes). The dependence on i and β is such that the four-fold ambiguity typical of the circular polarization observations ((i,β), (β,i), (π-i,π-β), (π-β,π-i)) can be removed.

scholarly journals Alinement of Solid Interstellar Particles by a Magnetic Field

1965 ◽  
Vol 7 ◽  
pp. 73-76
Author(s):  
Lyman Spitzer ◽  
R. V. Jones
Keyword(s):  
Magnetic Field ◽  
Basic Mechanism ◽  
Thermal Fluctuations ◽  
Solid Particles ◽  
Large Field ◽  
Interstellar Space ◽  
Interstellar Grains ◽  
Long Time ◽  
Satisfactory State ◽  
The Magnetic Field

For a Long Time the Davis-Greenstein Theory (ref. 1) has been generally considered an adequate explanation of the mechanism responsible for the alinement of interstellar grains and thus for the observed interstellar polarization. The magnetic field required to orient paramagnetic grains is apparently somewhat greater than 10-5 gauss, a relatively large field, but according to reference 2 ferromagnetic grains, proposed by the authors of reference 3, can be oriented by a field of only 10-7 gauss. These results indicate that orientation of interstellar grains is easily explained, even if the magnetic field in interstellar space is relatively weak.Unfortunately, this relatively satisfactory state of affairs has been upset by two developments. Firstly, the basic mechanism of magnetic relaxation proposed by Davis and Greenstein has been questioned by Dr. C. Kittel of the University of California, who has pointed out that the disorienting effect associated with thermal fluctuations of magnetization within the solid particles is ignored in the formulation of this mechanism.

scholarly journals Final Design of the Magnetic Field for the K-800 Superconducting Cyclotron at MSU

1981 ◽  
Vol 28 (3) ◽  
pp. 2749-2751 ◽  
Author(s):  
F. G. Resmini ◽  
G. Bellomo ◽  
H. G. Blosser ◽  
E. Fabrici ◽  
D. Johnson
Keyword(s):  
Magnetic Field ◽  
Superconducting Cyclotron ◽  
Final Design ◽  
The Magnetic Field

Development and Application of Multi-Modular Roll Magnetic Separator

2012 ◽  
Vol 472-475 ◽  
pp. 912-916
Author(s):  
Ding Guo Huang ◽  
Song Liu ◽  
Hong Guang Jiao ◽  
Fei Yue Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Material ◽  
Permanent Magnet ◽  
Magnetic Force ◽  
Economic Benefits ◽  
Magnet System ◽  
Magnetic Separator ◽  
Perfect Performance ◽  
One Machine ◽  
The Magnetic Field

This new dry magnetic separator has a special structure. It has many magnetic roll which are staggered like a stairsteps. It can finish the task of separating different minerals with only this one machine. And also it can make the different magnetic material which are in the same mineral separate at the same time. The permanent magnet system is made of large fan-shaped magnet. The magnet pole N and S are staggered and has perfect performance of magnetic separation. And the magnetic force is made full use by going-up dynamic separation. And also it gives an analysis of stress in the magnetic field. It also shows that its separation idex is better, the economic benefits are obvious, and it has broader prospects of popularization and application.

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.

Peculiar vortex structures in Fulde-Ferrell-Larkin-Ovchinnikov phase

2002 ◽  
Vol 12 (9) ◽  
pp. 385-388
Author(s):  
A. Buzdin ◽  
M. Houzet
Keyword(s):  
Magnetic Field ◽  
Upper Critical Field ◽  
Fflo State ◽  
First Order ◽  
State Observation ◽  
Field Versus ◽  
Excellent Candidate ◽  
Long Time ◽  
The Magnetic Field ◽  
2D Superconductors

A long time ago, it was predicted by Larkin and Ovchinnikov and Fulde and Ferrell that the non-uniform superconducting state (FFLO state) must appear in the magnetic field acting on the electron spins. Up to now, there have been no unambiguous experimental proofs in the favour of this state observation. We discuss the unusual properties of such a state, which can permit its identification. It is demonstrated that in 2D (or quasi 2D) superconductors the FFLO state leads to an appearance of a very special oscillatory - like dependence of the upper critical field versus the angle with the respect to the layers. The new solutions, corresponding to the higher Landau level functions are realized, and the vortex lattice structures are quite exotic. Corresponding vortex states reveal the zeros of superconducting order parameter with high winding numbers. The predicted quasi-oscillatory angular and temperature dependence of Bc2, as well as a cascade of first order transitions must permit the unambiguous identification of mysterious FFLO state. Very recently the magnetic-field-induced superconductivity has been observed in the quasi two-dimensional (2d) organic conductor (BETS)2FeCI4 which is an excellent candidate for the observation of the discussed effects.

scholarly journals Simulations of the impact of small details on the magnetic fileld distribution for the compact superconducting cyclotron SC200 commissioning

2019 ◽  
Vol 201 ◽  
pp. 07002
Author(s):  
Dmitry Popov ◽  
Oleg Karamyshev ◽  
Galina Karamysheva ◽  
Vladimir Malinin ◽  
Grigori Shirkov
Keyword(s):  
Magnetic Field ◽  
Virtual Reality ◽  
Field Distribution ◽  
High Precision ◽  
High Performance ◽  
Magnetic Field Distribution ◽  
The Real ◽  
Superconducting Cyclotron ◽  
The Impact ◽  
The Magnetic Field

Modern packages for the design and simulation of cyclotron magnet systems, such as Tosca, CST Studio, Comsol, etc., combined with recent hardware of high performance, allow us to simulate and estimate even a subtle impact on the magnetic field distribution caused by small details and other systems of the accelerator. Such reckoning provides the data to perform and simulate the refilnement of the magnet called the ‘shimming’. That means a signifilcant part of the commissioning stage could be done in ‘virtual reality’. This could substantially decrease the duration of the shimming procedure of the real magnet and the amount of the material wasted on it, eventually this results in a fileld of high-precision which could be compared to real one.

A compact permanent-magnet system for measuring magnetic circular dichroism in resonant inelastic soft X-ray scattering

2017 ◽  
Vol 24 (2) ◽  
pp. 449-455 ◽  
Author(s):  
Jun Miyawaki ◽  
Shigemasa Suga ◽  
Hidenori Fujiwara ◽  
Hideharu Niwa ◽  
Hisao Kiuchi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnets ◽  
Magnetic Circular Dichroism ◽  
X Rays ◽  
Magnet System ◽  
X Ray ◽  
X Ray Scattering ◽  
Magnetic Dichroism ◽  
The Magnetic Field ◽  
Ray Scattering

A compact and portable magnet system for measuring magnetic dichroism in resonant inelastic soft X-ray scattering (SX-RIXS) has been developed at the beamline BL07LSU in SPring-8. A magnetic circuit composed of Nd–Fe–B permanent magnets, which realised ∼0.25 T at the center of an 11 mm gap, was rotatable around the axis perpendicular to the X-ray scattering plane. Using the system, a SX-RIXS spectrum was obtained under the application of the magnetic field at an angle parallel, nearly 45° or perpendicular to the incident X-rays. A dedicated sample stage was also designed to be as compact as possible, making it possible to perform SX-RIXS measurements at arbitrary incident angles by rotating the sample stage in the gap between the magnetic poles. This system enables facile studies of magnetic dichroism in SX-RIXS for various experimental geometries of the sample and the magnetic field. A brief demonstration of the application is presented.

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