RUPAC2012 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
MOPPA018	Localization of the RF Breakdown in the Parallel Coupled Accelerating Structure	cavity, acceleration, electron, collider	281
	Y.D. Chernousov, A.M. Barnyakov, A.E. Levichev, V.M. Pavlov BINP SB RAS, Novosibirsk, Russia V. Ivannikov, I.V. Shebolaev ICKC SB RAS, Novosibirsk, Russia
	Parallel coupled accelerating structures (PCAS) with parallel RF power feeding of accelerating cavities has some features and advantages in compare with conventional traveling wave and standing wave structures with sequential RF power feeding. Parallel feeding of accelerating cavities minimizes the RF power flow via coupling slot and determines individual behavior of each cell in the regime of RF breakdown. These features can be used for developing of high gradient accelerating structures. The experimental data of the breakdown modes in the PCAS are presented.

WEPPC001	A Simulation Study on Accelerator Cavities for a SW Linac	cavity, impedance, linac, simulation	445
	N. Khosravi Zanjan University, Zanjan, Iran E.E. Ebrahimibasabi, S.A.H. Feghhi sbu, Tehran, Iran
	An on axis-coupled cavity structure has been studied using S-band microwaves at 2856 MHz, suitable for industrial and research applications. It uses a bi-periodic SW structure with constant impedance that operates at pi/2 mode. This structure consist Kidney-like shaped slots, placed symmetrically with respect to the accelerating axis. We compared Different shapes, places and sizes of slots with respect to coupling coefficient, resonance frequency and some of cavity parameters. Sensitivity analyses of accelerating cavity on details of structure have been done and their behavior, with respect to the resonance frequency has been presented. According to the simulation result using SUPERFISH and CST Studio package, each accelerating cavity is capable to deliver 0.56 MeV to electrons in a 50 mA beam.

WEPPC004	Maximum Value of the Standing Wave and Travelling Wave Accelerating Structures Electronic Efficiency	electron, cavity, radiation, linac	453
	S. Proskin, A. Kulago MEPhI, Moscow, Russia
	A new theoretical approach for a calculation of the standing wave structure electronic efficiency is described. As a result the electronic efficiency of the biperiodic structure is evaluated regarding a new definition

WEPPC008	Biperiodic Accelerating Structure with Inner Coupling Cells with an Increased Coupling Coefficient	cavity, simulation, multipactoring, linac	458
	M. Gusarova, I.I. Petrushina, E.A. Savin, N.P. Sobenin, D.B. Tikhonov MEPhI, Moscow, Russia
	Results on coupling increase research for biperiodic accelerating structure featuring high effective shunt impedance and other electrodynamical characteristics are presented. Accelerating structure for sample facility was designed taking into consideration thermal issues and multipactor discharge immunity.

WEPPC042	Design Parameters of Biperiodic Accelerating Structure for Medical Linac with Widely Variable Energy	electron, injection, simulation, medical-accelerators	529
	Yu. Zuev, M.A. Kalinichenko, V.V. Terentiev NIIEFA, St. Petersburg, Russia
	Results on the simulation of beam dynamics in an accelerating structure with regulation of particle energy from 6 to 21 MeV are presented. The structure operates in the standing wave mode, consists of two weakly coupled substructures and resonates at closed frequencies f1 , f2. In-phased electromagnetic field oscillations take place in the substructures at frequency f1, whereas anti-phased oscillations occur at frequency f2. Main features of the accelerating structure are electronic control of the beam energy and possibility to form narrow energy spread at both frequencies.

WEPPC046	RF Photoinjector Parameters Optimization	vacuum, impedance, electron, radiation	535
	T.V. Bondarenko, S.M. Polozov MEPhI, Moscow, Russia
	Sources of high-power electromagnetic radiation in THz band are becoming promising as a new method of a low activation introscopy. Research and development of accelerating RF photoinjector for THz source are reported. The photoinjector is based on disk loaded waveguide (DLW). Photoinjector consists of two accelerating structures: widespread 1.6 cell DLW structure and travelling wave resonator structure based on 8 cells traveling wave accelerating structure. The resonant models of these structures and the structures with power ports were designed. Electrodynamics characteristics and electric field distribution for all models were acquired. Electrodynamics models were tuned to the resonant frequency of 3000 MHz. Magnetic field coupling between cells of accelerating structure and optimization of the diaphragms sizes were analyzed to enlarge the structures efficiency. Diaphragms windows profiles were optimized to decrease the overvoltage on the windows edges and to eliminate the breakdown possibility.

WEPPD007	Vertical Size of an Electron Beam at Siberia-2	quadrupole, betatron, sextupole, closed-orbit	578
	A.G. Valentinov, V. Korchuganov, Y.V. Krylov, Y.L. Yupinov NRC, Moscow, Russia
	Brightness of the synchrotron radiation light sources is defined by electron beam sizes at radiation point. Horizontal size depends mainly from designed magnetic structure. Vertical size is defined by two processes: first, betatron coupling between vertical and horizontal motions and second, presence of vertical dispersion function at bending magnets. Vertical dispersion creates non-zero vertical emittance even without coupling. The report is dedicated to methods of vertical beam size decreasing at Siberia-2 storage ring. There are two families of skew-quadrupoles on the ring, one lens of every family in each of 6 cells of the magnetic structure. After analyzing of betatron coupling coefficient equation we stayed only two lenses in each family. As a result family currents for coupling compensation became much lower. In order to decrease vertical dispersion a special algorithm was developed and tested. Vertical dispersion on BPM azimuths was corrected by vertical displacements of sextupoles for chromaticity compensation. Maximal value of the dispersion became four times lower. It leaded to prominent vertical beam size decreasing.

WEPPD047	The Optimization of RF Deflector Input Power Coupler	emittance, electron, simulation, diagnostics	650
	A.Yu. Smirnov, O.A. Adonev, N.P. Sobenin MEPhI, Moscow, Russia A.A. Zavadtsev Nano, Moscow, Russia
	This paper concerns the investigation of different types of input power cell for S-band RF electron deflector. This device serving for slice emittance diagnostics is a disc-loaded waveguide which operates with TE11-like wave in traveling wave regime with 120 deg phase shift per cell. Since this deflector meets the restriction on its length and has to provide high enough deflecting potential to a particle during its flight time it is significant to increase the transversal field strength in coupling cell or to shorten it so that the deflecting potential remains constant. The total structure consists of 14 regular cells and two couplers. As it is now all cells have the same length equal to D=33.34 mm and the field in couplers is lower than that of regular cells. In this paper different length are considered and numerically simulated in order to choose the best one.

Paper

Title

Other Keywords

Page

MOPPA018

Localization of the RF Breakdown in the Parallel Coupled Accelerating Structure

cavity, acceleration, electron, collider

281

Y.D. Chernousov, A.M. Barnyakov, A.E. Levichev, V.M. Pavlov
BINP SB RAS, Novosibirsk, Russia
V. Ivannikov, I.V. Shebolaev
ICKC SB RAS, Novosibirsk, Russia

Parallel coupled accelerating structures (PCAS) with parallel RF power feeding of accelerating cavities has some features and advantages in compare with conventional traveling wave and standing wave structures with sequential RF power feeding. Parallel feeding of accelerating cavities minimizes the RF power flow via coupling slot and determines individual behavior of each cell in the regime of RF breakdown. These features can be used for developing of high gradient accelerating structures. The experimental data of the breakdown modes in the PCAS are presented.

WEPPC001

A Simulation Study on Accelerator Cavities for a SW Linac

cavity, impedance, linac, simulation

445

N. Khosravi
Zanjan University, Zanjan, Iran
E.E. Ebrahimibasabi, S.A.H. Feghhi
sbu, Tehran, Iran

An on axis-coupled cavity structure has been studied using S-band microwaves at 2856 MHz, suitable for industrial and research applications. It uses a bi-periodic SW structure with constant impedance that operates at pi/2 mode. This structure consist Kidney-like shaped slots, placed symmetrically with respect to the accelerating axis. We compared Different shapes, places and sizes of slots with respect to coupling coefficient, resonance frequency and some of cavity parameters. Sensitivity analyses of accelerating cavity on details of structure have been done and their behavior, with respect to the resonance frequency has been presented. According to the simulation result using SUPERFISH and CST Studio package, each accelerating cavity is capable to deliver 0.56 MeV to electrons in a 50 mA beam.

WEPPC004

Maximum Value of the Standing Wave and Travelling Wave Accelerating Structures Electronic Efficiency

electron, cavity, radiation, linac

453

S. Proskin, A. Kulago
MEPhI, Moscow, Russia

A new theoretical approach for a calculation of the standing wave structure electronic efficiency is described. As a result the electronic efficiency of the biperiodic structure is evaluated regarding a new definition

WEPPC008

Biperiodic Accelerating Structure with Inner Coupling Cells with an Increased Coupling Coefficient

cavity, simulation, multipactoring, linac

458

M. Gusarova, I.I. Petrushina, E.A. Savin, N.P. Sobenin, D.B. Tikhonov
MEPhI, Moscow, Russia

Results on coupling increase research for biperiodic accelerating structure featuring high effective shunt impedance and other electrodynamical characteristics are presented. Accelerating structure for sample facility was designed taking into consideration thermal issues and multipactor discharge immunity.

WEPPC042

Design Parameters of Biperiodic Accelerating Structure for Medical Linac with Widely Variable Energy

electron, injection, simulation, medical-accelerators

529

Yu. Zuev, M.A. Kalinichenko, V.V. Terentiev
NIIEFA, St. Petersburg, Russia

Results on the simulation of beam dynamics in an accelerating structure with regulation of particle energy from 6 to 21 MeV are presented. The structure operates in the standing wave mode, consists of two weakly coupled substructures and resonates at closed frequencies f1 , f2. In-phased electromagnetic field oscillations take place in the substructures at frequency f1, whereas anti-phased oscillations occur at frequency f2. Main features of the accelerating structure are electronic control of the beam energy and possibility to form narrow energy spread at both frequencies.

WEPPC046

RF Photoinjector Parameters Optimization

vacuum, impedance, electron, radiation

535

T.V. Bondarenko, S.M. Polozov
MEPhI, Moscow, Russia

Sources of high-power electromagnetic radiation in THz band are becoming promising as a new method of a low activation introscopy. Research and development of accelerating RF photoinjector for THz source are reported. The photoinjector is based on disk loaded waveguide (DLW). Photoinjector consists of two accelerating structures: widespread 1.6 cell DLW structure and travelling wave resonator structure based on 8 cells traveling wave accelerating structure. The resonant models of these structures and the structures with power ports were designed. Electrodynamics characteristics and electric field distribution for all models were acquired. Electrodynamics models were tuned to the resonant frequency of 3000 MHz. Magnetic field coupling between cells of accelerating structure and optimization of the diaphragms sizes were analyzed to enlarge the structures efficiency. Diaphragms windows profiles were optimized to decrease the overvoltage on the windows edges and to eliminate the breakdown possibility.

WEPPD007

Vertical Size of an Electron Beam at Siberia-2

quadrupole, betatron, sextupole, closed-orbit

578

A.G. Valentinov, V. Korchuganov, Y.V. Krylov, Y.L. Yupinov
NRC, Moscow, Russia

Brightness of the synchrotron radiation light sources is defined by electron beam sizes at radiation point. Horizontal size depends mainly from designed magnetic structure. Vertical size is defined by two processes: first, betatron coupling between vertical and horizontal motions and second, presence of vertical dispersion function at bending magnets. Vertical dispersion creates non-zero vertical emittance even without coupling. The report is dedicated to methods of vertical beam size decreasing at Siberia-2 storage ring. There are two families of skew-quadrupoles on the ring, one lens of every family in each of 6 cells of the magnetic structure. After analyzing of betatron coupling coefficient equation we stayed only two lenses in each family. As a result family currents for coupling compensation became much lower. In order to decrease vertical dispersion a special algorithm was developed and tested. Vertical dispersion on BPM azimuths was corrected by vertical displacements of sextupoles for chromaticity compensation. Maximal value of the dispersion became four times lower. It leaded to prominent vertical beam size decreasing.

WEPPD047

The Optimization of RF Deflector Input Power Coupler

emittance, electron, simulation, diagnostics

650

A.Yu. Smirnov, O.A. Adonev, N.P. Sobenin
MEPhI, Moscow, Russia
A.A. Zavadtsev
Nano, Moscow, Russia

This paper concerns the investigation of different types of input power cell for S-band RF electron deflector. This device serving for slice emittance diagnostics is a disc-loaded waveguide which operates with TE11-like wave in traveling wave regime with 120 deg phase shift per cell. Since this deflector meets the restriction on its length and has to provide high enough deflecting potential to a particle during its flight time it is significant to increase the transversal field strength in coupling cell or to shorten it so that the deflecting potential remains constant. The total structure consists of 14 regular cells and two couplers. As it is now all cells have the same length equal to D=33.34 mm and the field in couplers is lower than that of regular cells. In this paper different length are considered and numerically simulated in order to choose the best one.