RUPAC2012 - List of Keywords (resonance)

Paper	Title	Other Keywords	Page
TUBCH01	Transient Beam Response in Synchrotrons with a Digital Transverse Feedback System	feedback, damping, kicker, synchrotron	73
	V. Zhabitsky JINR, Dubna, Moscow Region, Russia
	The transient beam response on an externally applied impulse force in synchrotrons with a digital transverse feedback system is studied. Experimental data from the LHC on damping of coherent transverse oscillations excited by the discrete-time unit impulse are analysed. Good agreement on the measured and theoretically predicted decrements has been obtained. A method of feedback fine tuning, based on measurements of bunch response on harmonic excitation impulse, is discussed.
	Slides TUBCH01 [5.652 MB]

MOPPA021	176 MHz Solid State Microwave Generator Design	impedance, simulation, scattering, rf-amplifier	290
	A.Yu. Smirnov, E.V. Ivanov, K.I. Nikolskiy, S.A. Polikhov, N.V. Tikhomirova Siemens Research Center, Moscow,, Russia O. Heid, T.J.S. Hughes Siemens AG, Erlangen, Germany
	This paper concerns the R&D work upon design of a compact RF amplifier to be used for linear accelerators. The machine under development will operate at 176 MHz with output power of 25 kW in continuous wave regime. It consists of 48 push-pull PCB modules (approx. 500W output power each), connected in parallel to several radial filter rings, which both allow class-F operation and combine the power from the modules, delivering it to a single 50 Ω coax cable. The CST simulations and the results of 324 MHz test prototype measurements are presented.

TUPPB001	Study of Dynamical Aperture of NICA Collider with Account of Magnetic Field Errors and Coulomb Effects	collider, simulation, ion, synchrotron	304
	P.R. Zenkevich, A. Bolshakov ITEP, Moscow, Russia
	By use of MADX code beam dynamics in NICA collider has been studied. NICA collider has comparatively small kinetic ion energies (1.5-5 GeV/u) that results in one beam Coulomb effects. These effects are simulated by set of "BEAM-BEAM" elements with appropriate chosen strength and location. Besides it was taken into account beam-beam interaction and influence of systematic and random errors of the magnetic field. The simulation results are given and discussed.

TUPPB006	Compression and Confinement of Positron Clouds in the Surko Trap of LEPTA Facility	accumulation, positron, focusing, plasma	319
	M.K. Eseev, A.N. Vititnev NAFU, Arkhangelsk, Russia E.V. Ahmanova, A.G. Kobets, I.N. Meshkov, A.Yu. Rudakov, S. Yakovenko JINR, Dubna, Moscow Region, Russia
	A bunch of positrons confined in a cylindrical Penning-Malmberg trap can be compressed radially by applying a rotating asymmetric dipolar electric field. An explanation of this effect presented in the report is based on the solutions of particle 3D dynamics equations in the fields of the trap taking into account the positron collisions with a neutral buffer gas. The result agrees well with experimental data obtained at the positron injector of LEPTA facility at JINR. Essential feature of the compression process is resonant character of applied rotating field and coincidence its frequency with the frequency of longitudinal positron bouncing in the trap.

TUPPB016	Investigation of Phase Trajectories of Particles Motion in a Synchrotron Near the Nonlinear Resonance of Third Order	synchrotron, extraction, storage-ring, octupole	347
	Y.A. Bashmakov LPI, Moscow, Russia
	The nonlinear resonance of third order plays an important role in the particle dynamics in circular accelerators, colliders and storage rings and is widely used for slow extraction of particles from synchrotrons. Consideration is carried out in the canonical variables X, Y which at a given accelerator azimuth are simply related to the angle and the deviation of the circulating particles relative to the equilibrium orbit. The problem is reduced to the construction of the phase trajectories, which are the curves of the third or fourth order and determine the type of the motion near the resonance under consideration. The construction of the phase trajectories is performed by the Klein's perturbation method. The influence on the particles dynamics of oсtupole component of the magnetic fields is investigated.

TUPPB020	Mathematical Model of Beam Dynamics Optimization in Traveling Wave	controls, rfq, acceleration, injection	355
	A.D. Ovsyannikov, A.Yu. Shirokolobov St. Petersburg State University, St. Petersburg, Russia
	In works by B.I. Bondarev, A.P. Durkin, A.D. Ovsyannikov mathematical model of optimization of of charged particles dynamics in RFQ accelerators was proposed. In this paper a new mathematical model of optimization of particle dynamics in traveling wave is considered. Joint optimization model of program and disturbed motions is investigated.

TUPPB021	Calculation of Tolerance and Stastistical Test	controls, focusing, quadrupole	358
	Y.V. Yelaev St. Petersburg State University, St. Petersburg, Russia
	In the paper mathematical methods of tolerance determination of different parameters of accelerating and focusing structures are considered. The determination of tolerances is based on the analytical representation of variation of functional characterizing the beam dynamics. Method of statistical analysis of calculated tolerance values is represented. The purpose of the work is to determine the maximum possible deviations of the real (actual) parameters from nominal, when the qualitative structure function satisfies to the required modes.

TUPPB025	Investigation of Program and Perturbed Motions of Particles in Linear Accelerator	controls, electron, rfq, simulation	367
	I.D. Rubtsova, E.N. Suddenko St. Petersburg State University, St. Petersburg, Russia
	Beam control model for program and perturbed motions with interaction account is realized. Quality functional gradient is obtained.

TUPPB027	Some Problems of Beam Slow Extraction	extraction, feedback, controls, beam-transport	373
	S.N. Andrianov St. Petersburg State University, St. Petersburg, Russia
	Funding: The work is supported by Federal Targeted Program "Scientific and Scientific-Pedagogical Personnel of the Innovative Russia in 2009-2013" (Governmental Contract no. p 793) In this paper we discuss some problems of modeling of beam slow extraction systems. It is known that similar type of beam extraction is used for different kind of circular accelerators. Among the most important requirements for such systems is necessary to mention the time uniformity of the extracted beam. There exist the following two key causes. The first of them is induced by time discontinuity of the corresponding steering electrical currents, and the second cause is induced by an beam inertia which usually connected with beam feedback mechanism, which is usually used for temporal smoothing of the corresponding magnetic (and electrical) fields. In the base of our approach we put the matrix formalism for Lie algebraic tools, which allows us to analyze different kind of the time discontinuity cause.

WEPPD008	Energy Ramping at Siberia-2	betatron, quadrupole, injection, power-supply	581
	A.G. Valentinov, V. Korchuganov, Y.V. Krylov, Y.L. Yupinov NRC, Moscow, Russia
	Siberia-2 storage ring has great difference between injection energy 0.45 GeV and working energy 2.5 GeV. Beam lifetime at injection energy is equal to approximately 1 hour. In order to minimize beam losses of the stored beam it is necessary to accelerate energy ramping process. It is not very simple because power supplies of bending magnets, quadrupole lenses and sextupoles have different response time and behavior after changes in regulated current level. Magnetic elements are manufactured from non-laminated iron. It leads to slower field/gradient increasing at high current values. Complicated algorithm with 9 intermediate regimes (collections of power supplies' settings) was developed to produce fast and efficient energy ramping. First, correction of closed orbit, betatron tunes and chromaticity is accomplished in each regime in static conditions. Special file is used to provide acceleration or deceleration of power supplies in dynamic conditions. This scheme allows to compensate betatron tune shifts during energy ramping. Power supplies are not stopped on intermediate regimes; speed of current changing is continuous function of time. This algorithm allowed decreasing ramping time down to 2 minutes 40 seconds. Beam losses are not exceeding 2 – 3%; betatron tune shifts as a rule are lower than 0.01. The algorithm can easily be modified to stop in any intermediate regime.

Paper

Title

Other Keywords

Page

TUBCH01

Transient Beam Response in Synchrotrons with a Digital Transverse Feedback System

feedback, damping, kicker, synchrotron

73

V. Zhabitsky
JINR, Dubna, Moscow Region, Russia

The transient beam response on an externally applied impulse force in synchrotrons with a digital transverse feedback system is studied. Experimental data from the LHC on damping of coherent transverse oscillations excited by the discrete-time unit impulse are analysed. Good agreement on the measured and theoretically predicted decrements has been obtained. A method of feedback fine tuning, based on measurements of bunch response on harmonic excitation impulse, is discussed.

Slides TUBCH01 [5.652 MB]

MOPPA021

176 MHz Solid State Microwave Generator Design

impedance, simulation, scattering, rf-amplifier

290

A.Yu. Smirnov, E.V. Ivanov, K.I. Nikolskiy, S.A. Polikhov, N.V. Tikhomirova
Siemens Research Center, Moscow,, Russia
O. Heid, T.J.S. Hughes
Siemens AG, Erlangen, Germany

This paper concerns the R&D work upon design of a compact RF amplifier to be used for linear accelerators. The machine under development will operate at 176 MHz with output power of 25 kW in continuous wave regime. It consists of 48 push-pull PCB modules (approx. 500W output power each), connected in parallel to several radial filter rings, which both allow class-F operation and combine the power from the modules, delivering it to a single 50 Ω coax cable. The CST simulations and the results of 324 MHz test prototype measurements are presented.

TUPPB001

Study of Dynamical Aperture of NICA Collider with Account of Magnetic Field Errors and Coulomb Effects

collider, simulation, ion, synchrotron

304

P.R. Zenkevich, A. Bolshakov
ITEP, Moscow, Russia

By use of MADX code beam dynamics in NICA collider has been studied. NICA collider has comparatively small kinetic ion energies (1.5-5 GeV/u) that results in one beam Coulomb effects. These effects are simulated by set of "BEAM-BEAM" elements with appropriate chosen strength and location. Besides it was taken into account beam-beam interaction and influence of systematic and random errors of the magnetic field. The simulation results are given and discussed.

TUPPB006

Compression and Confinement of Positron Clouds in the Surko Trap of LEPTA Facility

accumulation, positron, focusing, plasma

319

M.K. Eseev, A.N. Vititnev
NAFU, Arkhangelsk, Russia
E.V. Ahmanova, A.G. Kobets, I.N. Meshkov, A.Yu. Rudakov, S. Yakovenko
JINR, Dubna, Moscow Region, Russia

A bunch of positrons confined in a cylindrical Penning-Malmberg trap can be compressed radially by applying a rotating asymmetric dipolar electric field. An explanation of this effect presented in the report is based on the solutions of particle 3D dynamics equations in the fields of the trap taking into account the positron collisions with a neutral buffer gas. The result agrees well with experimental data obtained at the positron injector of LEPTA facility at JINR. Essential feature of the compression process is resonant character of applied rotating field and coincidence its frequency with the frequency of longitudinal positron bouncing in the trap.

TUPPB016

Investigation of Phase Trajectories of Particles Motion in a Synchrotron Near the Nonlinear Resonance of Third Order

synchrotron, extraction, storage-ring, octupole

347

Y.A. Bashmakov
LPI, Moscow, Russia

The nonlinear resonance of third order plays an important role in the particle dynamics in circular accelerators, colliders and storage rings and is widely used for slow extraction of particles from synchrotrons. Consideration is carried out in the canonical variables X, Y which at a given accelerator azimuth are simply related to the angle and the deviation of the circulating particles relative to the equilibrium orbit. The problem is reduced to the construction of the phase trajectories, which are the curves of the third or fourth order and determine the type of the motion near the resonance under consideration. The construction of the phase trajectories is performed by the Klein's perturbation method. The influence on the particles dynamics of oсtupole component of the magnetic fields is investigated.

TUPPB020

Mathematical Model of Beam Dynamics Optimization in Traveling Wave

controls, rfq, acceleration, injection

355

A.D. Ovsyannikov, A.Yu. Shirokolobov
St. Petersburg State University, St. Petersburg, Russia

In works by B.I. Bondarev, A.P. Durkin, A.D. Ovsyannikov mathematical model of optimization of of charged particles dynamics in RFQ accelerators was proposed. In this paper a new mathematical model of optimization of particle dynamics in traveling wave is considered. Joint optimization model of program and disturbed motions is investigated.

TUPPB021

Calculation of Tolerance and Stastistical Test

controls, focusing, quadrupole

358

Y.V. Yelaev
St. Petersburg State University, St. Petersburg, Russia

In the paper mathematical methods of tolerance determination of different parameters of accelerating and focusing structures are considered. The determination of tolerances is based on the analytical representation of variation of functional characterizing the beam dynamics. Method of statistical analysis of calculated tolerance values is represented. The purpose of the work is to determine the maximum possible deviations of the real (actual) parameters from nominal, when the qualitative structure function satisfies to the required modes.

TUPPB025

Investigation of Program and Perturbed Motions of Particles in Linear Accelerator

controls, electron, rfq, simulation

367

I.D. Rubtsova, E.N. Suddenko
St. Petersburg State University, St. Petersburg, Russia

Beam control model for program and perturbed motions with interaction account is realized. Quality functional gradient is obtained.

TUPPB027

Some Problems of Beam Slow Extraction

extraction, feedback, controls, beam-transport

373

S.N. Andrianov
St. Petersburg State University, St. Petersburg, Russia

Funding: The work is supported by Federal Targeted Program "Scientific and Scientific-Pedagogical Personnel of the Innovative Russia in 2009-2013" (Governmental Contract no. p 793)
In this paper we discuss some problems of modeling of beam slow extraction systems. It is known that similar type of beam extraction is used for different kind of circular accelerators. Among the most important requirements for such systems is necessary to mention the time uniformity of the extracted beam. There exist the following two key causes. The first of them is induced by time discontinuity of the corresponding steering electrical currents, and the second cause is induced by an beam inertia which usually connected with beam feedback mechanism, which is usually used for temporal smoothing of the corresponding magnetic (and electrical) fields. In the base of our approach we put the matrix formalism for Lie algebraic tools, which allows us to analyze different kind of the time discontinuity cause.

WEPPD008

Energy Ramping at Siberia-2

betatron, quadrupole, injection, power-supply

581

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

Siberia-2 storage ring has great difference between injection energy 0.45 GeV and working energy 2.5 GeV. Beam lifetime at injection energy is equal to approximately 1 hour. In order to minimize beam losses of the stored beam it is necessary to accelerate energy ramping process. It is not very simple because power supplies of bending magnets, quadrupole lenses and sextupoles have different response time and behavior after changes in regulated current level. Magnetic elements are manufactured from non-laminated iron. It leads to slower field/gradient increasing at high current values. Complicated algorithm with 9 intermediate regimes (collections of power supplies' settings) was developed to produce fast and efficient energy ramping. First, correction of closed orbit, betatron tunes and chromaticity is accomplished in each regime in static conditions. Special file is used to provide acceleration or deceleration of power supplies in dynamic conditions. This scheme allows to compensate betatron tune shifts during energy ramping. Power supplies are not stopped on intermediate regimes; speed of current changing is continuous function of time. This algorithm allowed decreasing ramping time down to 2 minutes 40 seconds. Beam losses are not exceeding 2 – 3%; betatron tune shifts as a rule are lower than 0.01. The algorithm can easily be modified to stop in any intermediate regime.