scholarly journals TRAVELLING WAVE AND STANDING WAVE SINGLE CELL HIGH GRADIENT TESTS

2004 ◽  
Author(s):  
V Dolgashev
Keyword(s):  
Single Cell ◽  
Standing Wave ◽  
Travelling Wave ◽  
High Gradient

Interaction Between Coriolis Forces and Mistuning on a Cyclic Symmetric Structure With Geometrical Nonlinearity

2020 ◽  
Author(s):  
Anthony Tacher ◽  
Fabrice Thouverez ◽  
Jason Armand
Keyword(s):  
Standing Wave ◽  
Geometrical Nonlinearity ◽  
Numerical Approach ◽  
Travelling Wave ◽  
Lumped Parameter Model ◽  
Coriolis Forces ◽  
High Speeds ◽  
Symmetric Structure ◽  
Lumped Parameter ◽  
Cyclic Symmetric

Abstract An investigation of the interaction between Coriolis forces and mistuning on a cyclic symmetric structure is presented in this paper. The sensitivity of the eigenvalues and eigenvectors to mistuning is first studied with the perturbation method. A lumped parameter model is used to perform a modal analysis using a numerical approach after which geometrical nonlinearity is added to compare behavior with the linear case. Two different modes are thoroughly investigated for different rotational speeds, the first with an eigenvalue isolated from the others and the second presenting a frequency veering zone. The evolution from a standing wave domination at low speeds to a travelling wave domination at high speeds is observed for the isolated mode, whereas a standing wave domination remains around the veering zone for the second mode studied. It is also shown that the geometrical nonlinearity reinforces the mistuning effect versus the Coriolis forces.

A high gradient test of a single-cell superconducting radio frequency cavity with a feedback waveguide

2015 ◽  
Vol 28 (9) ◽  
pp. 095007 ◽  
Author(s):  
Roman Kostin ◽  
Pavel Avrakhov ◽  
Alexei Kanareykin ◽  
Nikolay Solyak ◽  
Vyacheslav Yakovlev ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Single Cell ◽  
High Gradient ◽  
Superconducting Radio Frequency

scholarly journals Development of a novel approach for construction of high gradient braze-free S-band cavities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mahdi Aghayan ◽  
S. Farhad Masoudi ◽  
Farshad Ghasemi ◽  
Walter Wuensch ◽  
Hamed Shaker
Keyword(s):  
High Temperature ◽  
Radio Frequency ◽  
Standing Wave ◽  
Wave Structure ◽  
Linear Accelerators ◽  
High Gradient ◽  
Novel Approach ◽  
Shrink Fit ◽  
Temperature Heating ◽  
High Temperature Heating

AbstractVacuum breakdown is one of the main limitations to the operating accelerating gradient in radio frequency linear accelerators. Recent studies of copper cavities have been shown that harder copper conditions more quickly and can reach higher accelerating gradients than soft copper cavities. Exploiting this advantage requires the development of assembly methods that do not involve the copper-softening high-temperature heating cycles that are used in for example bonding and brazing. A shrink-fit method, which was already implemented successfully in the operation the IPM linac, is proposed for the construction high-gradient test S-band standing wave structure operating at 2998.5 MHz. The three cells cavity is designed to have a maximum gradient in the middle cell that is twice that of the adjacent cells. Mechanical considerations relating to the shrink-fit construction method have been performed using Ansys. To validate the simulations and ensure the feasibility of construction by shrink-fit method, a sample cavity was constructed and cold tests was performed.

Interaction Between Coriolis Forces and Mistuning on a Cyclic Symmetric Structure with Geometrical Nonlinearity

2020 ◽  
Author(s):  
Anthony Tacher ◽  
Fabrice Thouverez ◽  
Jason Armand
Keyword(s):  
Standing Wave ◽  
Geometrical Nonlinearity ◽  
Numerical Approach ◽  
Travelling Wave ◽  
Lumped Parameter Model ◽  
Coriolis Forces ◽  
High Speeds ◽  
Symmetric Structure ◽  
Lumped Parameter ◽  
Cyclic Symmetric

Abstract An investigation of the interaction between Coriolis forces and mistuning on a cyclic symmetric structure is presented in this paper. The sensitivity of the eigenvalues and eigenvectors to mistuning is first studied with the perturbation method. A lumped parameter model is used to perform a modal analysis using a numerical approach after which geometrical nonlinearity is added to compare behavior with the linear case. Two different modes are thoroughly investigated for different rotational speeds, the first with an eigenvalue isolated from the others and the second presenting a frequency veering zone. The evolution from a standing wave domination at low speeds to a travelling wave domination at high speeds is observed for the isolated mode, whereas a standing wave domination remains around the veering zone for the second mode studied. It is also shown that the geometrical nonlinearity reinforces the mistuning effect versus the Coriolis forces.

Weakly nonlinear oscillatory convection in a rotating fluid

1992 ◽  
Vol 436 (1896) ◽  
pp. 33-54 ◽  
Keyword(s):  
Standing Wave ◽  
Perturbation Technique ◽  
Vertical Axis ◽  
Travelling Wave ◽  
Base Flow ◽  
Two Dimensional ◽  
Oscillatory Convection ◽  
Weakly Nonlinear ◽  
Wave Disturbances ◽  
The Stability

The problem of weakly nonlinear two- and three-dimensional oscillatory convection in the form of standing waves is studied for a horizontal layer of fluid heated from below and rotating about a vertical axis. The solutions to the nonlinear problem are determined by a perturbation technique and the stability of all the base flow solutions is investigated with respect to both standing wave and travelling wave disturbances. The results of the stability and the nonlinear analyses for various values of the rotation parameter τ and the Prandtl number P (0 ≼ P < 0.677) indicate that there is no subcritical instability and that all the base flow solutions are unstable. Disturbances with highest growth rates are found to be some particular disturbances superimposed on two-dimensional base flow. Particular standing wave disturbances parallel to two-dimensional base flow are the most unstable ones either for sufficiently small P or for intermediate values of P with τ below some critical value τ *. Travelling wave disturbances inclined at an angle of about 45° to the wave vector of two-dimensional base flow are the most unstable disturbances either for P sufficiently close to its upper limit or for intermediate values of P with τ ≽ τ *. The dependence on P and τ of the nonlinear effect on the frequency and of the heat flux are also discussed.

Electron Acceleration Using High Gradient Single Cell Resonators

1985 ◽  
Vol 32 (5) ◽  
pp. 2927-2929
Author(s):  
H. A. Schwettman ◽  
T. I. Smith ◽  
C. E. Hess
Keyword(s):  
Single Cell ◽  
Electron Acceleration ◽  
High Gradient

Investigation of the Velocity Profiles in a Ninety-Degree Curved Standing Wave Resonator with Particle Image Velocimetry

2013 ◽  
Vol 388 ◽  
pp. 8-12 ◽  
Author(s):  
Normah Mohd Ghazali ◽  
Irfan Abd Rahim ◽  
Terry Quenet ◽  
Zaki Ab Muin
Keyword(s):  
Particle Image Velocimetry ◽  
Standing Wave ◽  
Particle Image ◽  
Velocity Profiles ◽  
Travelling Wave ◽  
Straight Tube ◽  
Heat Engines ◽  
Quarter Wavelength ◽  
Wave Resonator ◽  
Image Velocimetry

Travelling wave thermoacoustic heat engines have been reported to have a higher efficiency than the standing wave ones. The former are generally large systems which consist of toroidal shape resonators. While standing wave heat engines are inherently smaller, a reduction in size could be considered which may involve curvatures as compared to the straight tube conventional systems. However, as with the streaming losses in the travelling wave resonators, losses due to the curvature may be generated. This study involves preliminary experimental measurements using the Particle Image Velocimetry (PIV) method to analyze the velocity profiles in a standing wave resonator before and after a ninety degree curvature. This design can reduce the space generally occupied by the straight standing wave resonator. The overall length of the resonator fits a quarter wavelength wave based on the straight closed-end tube type. The working gas is air at 1 atmospheric pressure. Results have shown that the velocity profiles after the stack but before the curvature exhibit clear straight paths up just as reported elsewhere. Signs of disordered motion could be observed just before the bend and the pattern continues until after the curvature. The results are obtained before one periodic cycle and before the acoustic wave front hit the tube end. The trend is expected to affect the overall thermoacoustic performance of the engine as returning gas particles interact with the oncoming particles that pass by the curvature.

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