RUPAC2012 - List of Keywords (focusing)

Paper	Title	Other Keywords	Page
MOACH02	Design and Simulation of Practical Alternating-Phase-Focused (APF) Linacs – Synthesis and Extension in Tribute to Pioneering Russian APF Research	linac, acceleration, emittance, ion	12
	R.A. Jameson IAP, Frankfurt am Main, Germany
	Conventional magnetic transverse focusing in conventional linacs represents a high fraction of their cost and complexity. Both transverse and longitudinal focusing can be obtained from the rf field by using the strong-focusing effect of alternating patterns (sequences) of gap phases and amplitudes – known as Alternating-Phase-Focusing (APF). Although studied for decades, the difficulty of designing suitable sequences has inhibited APF adoption, although short sequence APFs are now used in a number of practical applications. Synthesis of reported details and new physics and technique result in a new, general and efficient method for designing APF linacs. Very long sequences with high energy gain factors are demonstrated, e.g. for acceleration of very cold muons from ~0.340-200MeV (factor 600).
	Slides MOACH02 [0.616 MB]

TUZCH02	Mathematical Modeling and Optimization of Beam Dynamics in Accelerators	rfq, controls, quadrupole, electromagnetic-fields	68
	D.A. Ovsyannikov St. Petersburg State University, St. Petersburg, Russia
	In this paper we treat the problem of beam dynamics optimization as a control theory problems. We consider different mathematical model of optimization. The approach to solving optimization problem for charged particle dynamics in accelerators includes: construction of mathematical model of controlled dynamical process; choice of control functions or parameters of optimization; construction of quality functionals, which allow efficient evaluation of various characteristics of examined controlled motion; analytical representation of the functional variations, which allow to construct various methods of optimization for quality functionals; construction of methods and algorithms of optimization. Problem of statement is considered on the pattern of RFQ channel.
	Slides TUZCH02 [1.601 MB]

TUCCH02	Beam Dynamics Investigations for 433 MHz RFQ Accelerator	rfq, emittance, ion, injection	82
	Y.A. Svistunov NIIEFA, St. Petersburg, Russia A.P. Durkin MRTI RAS, Moscow, Russia A.D. Ovsyannikov St. Petersburg State University, St. Petersburg, Russia
	Modeling results for deuteron dynamics in RFQ structure with operational frequency 433 MHz and 1 MeV output energy are presented. The results are compared with experimental data. The purpose of investigation is to find optimal input RFQ emittance parameters for off-nominal values of input current and vane voltage.
	Slides TUCCH02 [0.642 MB]

WEACH01	Use of Bent-Crystal Deflectors to Steer Beam in U-70 Accelerator of IHEP - Status and Prospects	extraction, target, proton, ion	95
	A.G. Afonin, V.I. Baranov, Y.A. Chesnokov, V.A. Maisheev, V. Terekhov, I.A. Yazynin IHEP, Moscow Region, Russia
	The report presents an overview the results of IHEP activity in the field of study and using bent crystals to steer high-energy proton and ion beam obtained during 2010-2012. The hardware installed to study crystal collimation and extraction is described. A new dedicated beam transfer line was arranged to study the performance of crystals. It has been shown that the crystal deflectors developed are capable of sustaining long-term operation to deliver high-energy extracted beams for fixed-target physics. Experience with practical applications of bent crystals are outlined. First results on the extraction 24.1 GeV/nucleon carbon ions are also presented.

WEBOR02	Some Design Features of the 80 MeV H⁻ Isochronous Cyclotron at Gatchina	cyclotron, extraction, vacuum, injection	109
	G.A. Riabov, S.A. Artamonov, E.M. Ivanov, G.F. Mikheev, Yu.T. Mironov, B.B. Tokarev PNPI, Gatchina, Leningrad District, Russia V.G. Mudrolyubov NIIEFA, St. Petersburg, Russia
	To minimize the expenditures while designing the cyclotron an attempt was made to use at most the existing synchrocyclotron infrastructure, i.e. the building with the radiation shielding, the bridge crane for 30 tones, the electric power, water cooling, ventilation systems, etc. The iron yoke of the existing synchrocyclotron magnet model is used for a magnet system. The special magnetic structure with very low value of the flatter 0.025 and extremely high spiral angle about 60 degree in the radii range from 0.3 up to 0.9 m was developed to provide acceleration of H-minus ions up to energy 80 MeV in the magnet with extraction radius 0.9 m. Special attention was paid to thoroughly study effects of the highly spiraled structure: decrease of the flatter with introduction of the spiral angle, discrepancy between the magnetic and geometrical spiral angles, the spiral angle inefficiency in the cyclotron central region.
	Slides WEBOR02 [1.952 MB]

FRBCH01	Development of the IBA-JINR Cyclotron C235-V3 for Dimitrovgrad Hospital Center of the Proton Therapy	cyclotron, proton, extraction, beam-losses	221
	S.A. Kostromin, S. Gurskiy, G.A. Karamysheva, M.Y. Kazarinov, S.A. Korovkin, S.P. Mokrenko, N.A. Morozov, A.G. Olshevsky, V.M. Romanov, E. Samsonov, N.G. Shakun, G. Shirkov, S.G. Shirkov, E. Syresin JINR, Dubna, Moscow Region, Russia P. Cahay, Y. Jongen, Y. Paradis IBA, Louvain-la-Neuve, Belgium
	The Dimitrovgrad project, the first Russian hospital center of the proton therapy, was approved in 2010. The JINR-IBA collaboration developed and constructed the C235-V3 proton cyclotron for this center. The assembly and the beam tests of the machine were done in 2011-2012 in special experimental hall in JINR. This cyclotron is a substantially modified version C235-V3 of the IBA C235 serial cyclotron. C235-V3 has the improved extraction system which was constructed and tested. This system allows raise the extraction efficiency up to 77% from 50% in comparison with serial C235. Special mapping system (for Br-component) of the magnetic field was developed and constructed by JINR for the shimming of the Br-field in the middle plane of the cyclotron. Tests with accelerated and extracted beam were performed in August 2012 in JINR. Beam vertical motion in the cyclotron is in the acceptable limits (ΔZbeam≤3 mm). Transmission from r=300mm to 10³⁰ is 72% without beam cutting diaphragms. This allows reduce irradiation dose of the machine elements in comparison with serial C235. Extraction efficiency is 62%. Total efficiency of the machine is 45%. Recommendations are formulated to modify the magnetic system and reduce sensitivity of the machine to the magnetic field imperfections. Most of changes concerned with the increasing of the vertical focusing at the final radii.
	Slides FRBCH01 [6.282 MB]

FRBCH07	Transformation of Beams in the Plasma Lens and Investigation of Z-Pinch Dynamics	plasma, ion, simulation, laser	239
	A.A. Drozdovsky, N.N. Alexeev, S.A. Drozdovsky, A. Golubev, Yu.B. Novozhilov, P.V. Sasorov, S.M. Savin, V.V. Yanenko ITEP, Moscow, Russia
	Funding: Work supported by the Russian Foundation for Basic Research The plasma lens can carry out sharp focusing of ion beam with considerable reduction sizes of focal spot. At those stages of the plasma discharge at which the magnetic field is nonlinear, formation of other interesting configurations of beams is possible. The report presents the results of studies transformation the Gaussian beam into hollow one and into beam with homogeneous spatial distribution. The discharge current distributions obtained by numerical calculation ensure the experimental beam transformations. Thus possibility of the research of the plasma discharge dynamics by means of relativistic ions beams is shown. The plasma lens represents the universal device for scientific and technical applications in particular for irradiation of medical objects.
	Slides FRBCH07 [1.390 MB]

MOPPA001	Excitation of the Focusing Wakefields by a Relativistic Bunch in Isotropic Capillary Discharge Plasma	plasma, wakefield, electron, vacuum	242
	R.R. Kniaziev, G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine
	At present work excitation of wakefields by an relativistic electron bunch in a capillary tube filled with plasma is investigated. In the approximation of constant velocity of the bunches an analytical expressions for a components of an electromagnetic field are found. Numerical calculations of excited capillary tubes fields fabricated from the alumina and the quartz is carried out. Outer diameter of a capillary tube is equal 1 mm, inner diameter is 0.4 mm. In the absence of plasma in such structure the wakefields of the THz frequencies range are excited. Longitudinal and transverse profiles of wake fields in slow wave structure which drive channel is filled with plasma are investigated in details. These profiles allow to investigate dependences of wakefields from plasma density, the sizes of dielectric structure and/or the linear sizes of an electron bunch. When comparison of these dependences, it follows that there are longitudinal positions of the test bunch relative to the drive bunch, which can provide high-gradient acceleration of charged particles and their simultaneous radial focusing.

MOPPA009	An Analytical Approach to Solution of Self-coordinated Beam Dynamics in Dielectric Wakefield Accelerating Structures	wakefield, acceleration, radiation, electron	263
	I.L. Sheynman LETI, Saint-Petersburg, Russia
	Self-coordinated transverse dynamics of the high current relativistic electronic bunches used for generation of wake fields in wakefield accelerating structures with dielectric filling is investigated. An analytical approach to solution of self-coordinated beam dynamics is developed.

TUPPB005	LEPTA Project: Towards Positronium	positron, electron, gun, injection	316
	A.G. Kobets, E.V. Ahmanova, V.I. Lokhmatov, I.N. Meshkov, V. Pavlov, A.Yu. Rudakov, A.A. Sidorin, S. Yakovenko JINR, Dubna, Moscow Region, Russia M.K. Eseev NAFU, Arkhangelsk, Russia
	The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron coolin system. The project positron energy is of 2 – 10 keV. The main goal of the facility is to generate an intense flux of positronium atoms – the bound state of electron and positron. Storage ring of LEPTA facility was commissioned in September 2004 and was under development up to now. The positron injector has been constructed in 2005 - 2010, and beam transfer channel – in 2011. By the end of August 2011 experiments on electron and positron injection into the ring have been started. The recent results are presented here.

TUPPB006	Compression and Confinement of Positron Clouds in the Surko Trap of LEPTA Facility	accumulation, positron, resonance, 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.

TUPPB010	RF Quadrupole Focusing Lattices	rfq, lattice, quadrupole, linac	331
	A.S. Plastun, T.V. Bondarenko MEPhI, Moscow, Russia
	Spatial homogeneity of a conventional RFQ allows to estimate parameters of the lattice easily. Hybrid-RFQ structures with spatially periodic RFQ lenses are more complicated in respect of beam dynamics. Transverse stability of beam motion is defined by lattice parameters. Basically parameters of RF focusing lattices are influenced by longitudinal emittance of a bunch in contrast to static focusing lattices. The paper presents a method which allows to evaluate parameters of a very wide class of RF and static quadrupole lattices. Transverse acceptance and acceleration rate could be determined. The method is useful to compare Hybrid-RFQ structures with a conventional RFQ.

TUPPB012	Search of the Motion Integral at Linac with RF Focusing	linac, undulator, dynamic-aperture, ion	337
	V.S. Dyubkov, S.M. Polozov MEPhI, Moscow, Russia
	The problem of the effective low-energy linac design is of interest to many fields of science, industry and medicine. It is well known that nonsynchronous harmonics of RF field (RF undulator) are focusing the particles. Analytical beam dynamics investigation can be carried out by means of the averaging method over the rapid oscillations period (the so-called smooth approximation) in the oscillating fields. Motion equation is presented in the form of the Hamilton's equations. Motion integrals are found by means of Poincare mapping.

TUPPB021	Calculation of Tolerance and Stastistical Test	controls, quadrupole, resonance	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.

TUPPB022	Mathematical Model of Beam Dynamic Optimization	DTL, emittance, controls, linac	361
	V.V. Altsybeyev St. Petersburg State University, St. Petersburg, Russia
	We treat here the process of simulation of charged particle dynamics using so called hybrid system. Hybrid system is a system with continuous and discrete parts, described by differential and difference equations, respectively. In this case new mathematical model of beam dynamics optimization is suggested. The main parameters of optimization are: coefficient of particle capture in the acceleration mode, phase and energy spectra of particles at the exit of the accelerator, the transverse beam characteristics, etc. Optimization was carried out for the drift tubes accelerator.

TUPPB024	Development of the Object-oriented Program in C ++ for Simulation of Beam Dynamics in Accelerator Injection Systems	injection, simulation, controls, emittance	364
	S.A. Kozynchenko St. Petersburg State University, St. Petersburg, Russia
	At present, more and more attention is paid to the design and creation of accelerator systems for precision beams. Their injection systems in many aspects determine the output characteristics of the beam, so the questions of the design of such systems are of great importance. In such cases both simulation and optimization of beam dynamics in electromagnetic fields close to real may be necessary. In this paper the program for simulation and optimization of beam dynamics in injection systems is considered, which at the same time allows the choice of parameters of the accelerating-focusing system. This permits designing the injection system during optimization process, taking into account the required output characteristics of the beam. The given program is based on Win 32 API dialog boxes and is developed in standard C++, using parallel programming tools based on the MPI-1.

WEPPC009	Using Genetic Algorithms for Electrode Shape Optimization in Accelerators with RF Focusing	simulation, linac, acceleration, controls	461
	A.V. Samoshin, K.A. Aliev, S.M. Polozov MEPhI, Moscow, Russia
	The drift tubes shape choice which provides the require distribution of the spatial harmonics amplitudes of RF field is an important problem in the design of RF focusing accelerators. It is necessary to have various relationships of the main (accelerating) and the first (as main focusing) harmonics of RF field for different types of accelerators. High order harmonics should be negligible for accelerators with an external focusing, and this ratio should be E1/E0 = 3-5 for the efficient operation of the axially symmetric RF focusing accelerator. Thus, the distribution and harmonic amplitude's ratios at the accelerator axis which provides stable beam dynamics are always known. The drift tubes shape study problem cannot be solved directly by ordinary methods because of unknown boundary conditions belongs to a class of ill-posed problem. At present, this problem can be solved by using genetic algorithms (GA). For this purpose, the electrode shape will be represent as the polynomial function, and then solve the Laplace equation with boundary conditions of Dirichlet and Neumann. The necessary electrodes shape can be quickly and easily simulated using the adaptive search.

WEPPC024	Design, Simulation and Optimization of a Solenoid for ES-200 Electrostatic Accelerator	solenoid, simulation, target, proton	498
	M. Asgarpour, E.E. Ebrahimibasabi, S.A.H. Feghhi, M. Khorsandi sbu, Tehran, Iran N. Khosravi Zanjan University, Zanjan, Iran
	Solenoids have important role in focusing the beam in drift tube of charge particle accelerators. In order to optimize the beam current in ES-200, an electrostatic proton accelerator at Shahid Beheshti University, design and simulation of a suitable solenoid has been performed. Using CST Studio package, simulation results has been validated in comparison with theoretical formula. According to the results we optimized the design using CST to have minimum beam current on drift tube.

WEPPC038	RF Power and Control Systems for Phased Dipoles Array System for Hyperthermia	dipole, controls, electromagnetic-fields, site	524
	A.M. Fadeev, V.N. Belyaev, A.A. Blinnikov, S.M. Polozov MEPhI, Moscow, Russia E.A. Perelstein JINR, Dubna, Moscow Region, Russia
	Cylindrical array of independently phased dipoles is suggested for hyperthermia of deep-situated tumors as a kind of treatment of cancer coupled with other methods such as radiation therapy and chemotherapy. It was proposed to focus the maximum of electromagnetic field at the site of tumor to produce high efficiency heating of tumor and to prevent overheating of surrounding healthy tissues. That's why we use system of independently fed dipole antennas. The operating frequency is 150 MHz. The independent feeding permits us to focus electromagnetic field producing by phased array in desirable area by means of changing of amplitudes and phases of each dipole. The RF power system schematic layout for 8 independently phased dipole antennas is presented. The control system of RF power system elements is considered. The software developing to provide choosing amplitude's and phase's values of dipoles are discussed.

WEPPC056	Improving of Uniformity of the Electron-Beam Treatment of Materials by ELV Accelerators	electron, radiation, controls, scattering	557
	D.A. Kogut, S. Fadeev, N.K. Kuksanov BINP SB RAS, Novosibirsk, Russia
	The problem of the absorbed dose distribution during the EB treatment by ELV accelerator is considered. The value of the absorbed dose is determined by the speed of scanning electron beam along the accelerator exit window (i.e. the movement across the conveyor). It is determined both by the shape of scanning current and by the geometry of scanning magnets. A simple way to improve the dose distribution near the edges of the extraction device of accelerator is suggested. It allows to provide the non-uniformity less 4%.

WEPPD038	Optimization of the Negative Hydrogen Ion Beam Injection into the Tandem Accelerator with Vacuum Insulation	ion, proton, vacuum, tandem-accelerator	623
	A.N. Makarov, V.I. Aleynik, A.G. Bashkirtsev, A.S. Kuznetsov, I.M. Schudlo, I.N. Sorokin, S.Yu. Taskaev, M.A. Tiunov BINP SB RAS, Novosibirsk, Russia
	The beam of negative hydrogen ions is injected into the tandem accelerator with vacuum insulation in order to obtain high-current proton beam. To accurately direct the beam into the accelerator the magnetic focusing lenses are used. In this paper it is described the design of the special beam detector mounted in front of the first accelerating electrode and intended to measure beam profile and the current density. The results of measurements of the dependence of the current density on the power of the magnetic focusing lenses are shown. The parameters of the beam resulting in the best agreement of calculation and experiment are specified. The optimum focusing mode to inject the negative hydrogen ions into the accelerator is determined.

Paper

Title

Other Keywords

Page

Design and Simulation of Practical Alternating-Phase-Focused (APF) Linacs – Synthesis and Extension in Tribute to Pioneering Russian APF Research

linac, acceleration, emittance, ion

12

R.A. Jameson
IAP, Frankfurt am Main, Germany

Conventional magnetic transverse focusing in conventional linacs represents a high fraction of their cost and complexity. Both transverse and longitudinal focusing can be obtained from the rf field by using the strong-focusing effect of alternating patterns (sequences) of gap phases and amplitudes – known as Alternating-Phase-Focusing (APF). Although studied for decades, the difficulty of designing suitable sequences has inhibited APF adoption, although short sequence APFs are now used in a number of practical applications. Synthesis of reported details and new physics and technique result in a new, general and efficient method for designing APF linacs. Very long sequences with high energy gain factors are demonstrated, e.g. for acceleration of very cold muons from ~0.340-200MeV (factor 600).

Slides MOACH02 [0.616 MB]

TUZCH02

Mathematical Modeling and Optimization of Beam Dynamics in Accelerators

rfq, controls, quadrupole, electromagnetic-fields

68

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

In this paper we treat the problem of beam dynamics optimization as a control theory problems. We consider different mathematical model of optimization. The approach to solving optimization problem for charged particle dynamics in accelerators includes: construction of mathematical model of controlled dynamical process; choice of control functions or parameters of optimization; construction of quality functionals, which allow efficient evaluation of various characteristics of examined controlled motion; analytical representation of the functional variations, which allow to construct various methods of optimization for quality functionals; construction of methods and algorithms of optimization. Problem of statement is considered on the pattern of RFQ channel.

Slides TUZCH02 [1.601 MB]

TUCCH02

Beam Dynamics Investigations for 433 MHz RFQ Accelerator

rfq, emittance, ion, injection

82

Y.A. Svistunov
NIIEFA, St. Petersburg, Russia
A.P. Durkin
MRTI RAS, Moscow, Russia
A.D. Ovsyannikov
St. Petersburg State University, St. Petersburg, Russia

Modeling results for deuteron dynamics in RFQ structure with operational frequency 433 MHz and 1 MeV output energy are presented. The results are compared with experimental data. The purpose of investigation is to find optimal input RFQ emittance parameters for off-nominal values of input current and vane voltage.

Slides TUCCH02 [0.642 MB]

WEACH01

Use of Bent-Crystal Deflectors to Steer Beam in U-70 Accelerator of IHEP - Status and Prospects

extraction, target, proton, ion

95

A.G. Afonin, V.I. Baranov, Y.A. Chesnokov, V.A. Maisheev, V. Terekhov, I.A. Yazynin
IHEP, Moscow Region, Russia

The report presents an overview the results of IHEP activity in the field of study and using bent crystals to steer high-energy proton and ion beam obtained during 2010-2012. The hardware installed to study crystal collimation and extraction is described. A new dedicated beam transfer line was arranged to study the performance of crystals. It has been shown that the crystal deflectors developed are capable of sustaining long-term operation to deliver high-energy extracted beams for fixed-target physics. Experience with practical applications of bent crystals are outlined. First results on the extraction 24.1 GeV/nucleon carbon ions are also presented.

WEBOR02

Some Design Features of the 80 MeV H⁻ Isochronous Cyclotron at Gatchina

cyclotron, extraction, vacuum, injection

109

G.A. Riabov, S.A. Artamonov, E.M. Ivanov, G.F. Mikheev, Yu.T. Mironov, B.B. Tokarev
PNPI, Gatchina, Leningrad District, Russia
V.G. Mudrolyubov
NIIEFA, St. Petersburg, Russia

To minimize the expenditures while designing the cyclotron an attempt was made to use at most the existing synchrocyclotron infrastructure, i.e. the building with the radiation shielding, the bridge crane for 30 tones, the electric power, water cooling, ventilation systems, etc. The iron yoke of the existing synchrocyclotron magnet model is used for a magnet system. The special magnetic structure with very low value of the flatter 0.025 and extremely high spiral angle about 60 degree in the radii range from 0.3 up to 0.9 m was developed to provide acceleration of H-minus ions up to energy 80 MeV in the magnet with extraction radius 0.9 m. Special attention was paid to thoroughly study effects of the highly spiraled structure: decrease of the flatter with introduction of the spiral angle, discrepancy between the magnetic and geometrical spiral angles, the spiral angle inefficiency in the cyclotron central region.

Slides WEBOR02 [1.952 MB]

FRBCH01

Development of the IBA-JINR Cyclotron C235-V3 for Dimitrovgrad Hospital Center of the Proton Therapy

cyclotron, proton, extraction, beam-losses

221

S.A. Kostromin, S. Gurskiy, G.A. Karamysheva, M.Y. Kazarinov, S.A. Korovkin, S.P. Mokrenko, N.A. Morozov, A.G. Olshevsky, V.M. Romanov, E. Samsonov, N.G. Shakun, G. Shirkov, S.G. Shirkov, E. Syresin
JINR, Dubna, Moscow Region, Russia
P. Cahay, Y. Jongen, Y. Paradis
IBA, Louvain-la-Neuve, Belgium

The Dimitrovgrad project, the first Russian hospital center of the proton therapy, was approved in 2010. The JINR-IBA collaboration developed and constructed the C235-V3 proton cyclotron for this center. The assembly and the beam tests of the machine were done in 2011-2012 in special experimental hall in JINR. This cyclotron is a substantially modified version C235-V3 of the IBA C235 serial cyclotron. C235-V3 has the improved extraction system which was constructed and tested. This system allows raise the extraction efficiency up to 77% from 50% in comparison with serial C235. Special mapping system (for Br-component) of the magnetic field was developed and constructed by JINR for the shimming of the Br-field in the middle plane of the cyclotron. Tests with accelerated and extracted beam were performed in August 2012 in JINR. Beam vertical motion in the cyclotron is in the acceptable limits (ΔZbeam≤3 mm). Transmission from r=300mm to 10³⁰ is 72% without beam cutting diaphragms. This allows reduce irradiation dose of the machine elements in comparison with serial C235. Extraction efficiency is 62%. Total efficiency of the machine is 45%. Recommendations are formulated to modify the magnetic system and reduce sensitivity of the machine to the magnetic field imperfections. Most of changes concerned with the increasing of the vertical focusing at the final radii.

Slides FRBCH01 [6.282 MB]

FRBCH07

Transformation of Beams in the Plasma Lens and Investigation of Z-Pinch Dynamics

plasma, ion, simulation, laser

239

A.A. Drozdovsky, N.N. Alexeev, S.A. Drozdovsky, A. Golubev, Yu.B. Novozhilov, P.V. Sasorov, S.M. Savin, V.V. Yanenko
ITEP, Moscow, Russia

Funding: Work supported by the Russian Foundation for Basic Research
The plasma lens can carry out sharp focusing of ion beam with considerable reduction sizes of focal spot. At those stages of the plasma discharge at which the magnetic field is nonlinear, formation of other interesting configurations of beams is possible. The report presents the results of studies transformation the Gaussian beam into hollow one and into beam with homogeneous spatial distribution. The discharge current distributions obtained by numerical calculation ensure the experimental beam transformations. Thus possibility of the research of the plasma discharge dynamics by means of relativistic ions beams is shown. The plasma lens represents the universal device for scientific and technical applications in particular for irradiation of medical objects.

Slides FRBCH07 [1.390 MB]

MOPPA001

Excitation of the Focusing Wakefields by a Relativistic Bunch in Isotropic Capillary Discharge Plasma

plasma, wakefield, electron, vacuum

242

R.R. Kniaziev, G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine

At present work excitation of wakefields by an relativistic electron bunch in a capillary tube filled with plasma is investigated. In the approximation of constant velocity of the bunches an analytical expressions for a components of an electromagnetic field are found. Numerical calculations of excited capillary tubes fields fabricated from the alumina and the quartz is carried out. Outer diameter of a capillary tube is equal 1 mm, inner diameter is 0.4 mm. In the absence of plasma in such structure the wakefields of the THz frequencies range are excited. Longitudinal and transverse profiles of wake fields in slow wave structure which drive channel is filled with plasma are investigated in details. These profiles allow to investigate dependences of wakefields from plasma density, the sizes of dielectric structure and/or the linear sizes of an electron bunch. When comparison of these dependences, it follows that there are longitudinal positions of the test bunch relative to the drive bunch, which can provide high-gradient acceleration of charged particles and their simultaneous radial focusing.

MOPPA009

An Analytical Approach to Solution of Self-coordinated Beam Dynamics in Dielectric Wakefield Accelerating Structures

wakefield, acceleration, radiation, electron

263

I.L. Sheynman
LETI, Saint-Petersburg, Russia

Self-coordinated transverse dynamics of the high current relativistic electronic bunches used for generation of wake fields in wakefield accelerating structures with dielectric filling is investigated. An analytical approach to solution of self-coordinated beam dynamics is developed.

TUPPB005

LEPTA Project: Towards Positronium

positron, electron, gun, injection

316

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

The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron coolin system. The project positron energy is of 2 – 10 keV. The main goal of the facility is to generate an intense flux of positronium atoms – the bound state of electron and positron. Storage ring of LEPTA facility was commissioned in September 2004 and was under development up to now. The positron injector has been constructed in 2005 - 2010, and beam transfer channel – in 2011. By the end of August 2011 experiments on electron and positron injection into the ring have been started. The recent results are presented here.

TUPPB006

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

accumulation, positron, resonance, 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.

TUPPB010

RF Quadrupole Focusing Lattices

rfq, lattice, quadrupole, linac

331

A.S. Plastun, T.V. Bondarenko
MEPhI, Moscow, Russia

Spatial homogeneity of a conventional RFQ allows to estimate parameters of the lattice easily. Hybrid-RFQ structures with spatially periodic RFQ lenses are more complicated in respect of beam dynamics. Transverse stability of beam motion is defined by lattice parameters. Basically parameters of RF focusing lattices are influenced by longitudinal emittance of a bunch in contrast to static focusing lattices. The paper presents a method which allows to evaluate parameters of a very wide class of RF and static quadrupole lattices. Transverse acceptance and acceleration rate could be determined. The method is useful to compare Hybrid-RFQ structures with a conventional RFQ.

TUPPB012

Search of the Motion Integral at Linac with RF Focusing

linac, undulator, dynamic-aperture, ion

337

V.S. Dyubkov, S.M. Polozov
MEPhI, Moscow, Russia

The problem of the effective low-energy linac design is of interest to many fields of science, industry and medicine. It is well known that nonsynchronous harmonics of RF field (RF undulator) are focusing the particles. Analytical beam dynamics investigation can be carried out by means of the averaging method over the rapid oscillations period (the so-called smooth approximation) in the oscillating fields. Motion equation is presented in the form of the Hamilton's equations. Motion integrals are found by means of Poincare mapping.

TUPPB021

Calculation of Tolerance and Stastistical Test

controls, quadrupole, resonance

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.

TUPPB022

Mathematical Model of Beam Dynamic Optimization

DTL, emittance, controls, linac

361

V.V. Altsybeyev
St. Petersburg State University, St. Petersburg, Russia

We treat here the process of simulation of charged particle dynamics using so called hybrid system. Hybrid system is a system with continuous and discrete parts, described by differential and difference equations, respectively. In this case new mathematical model of beam dynamics optimization is suggested. The main parameters of optimization are: coefficient of particle capture in the acceleration mode, phase and energy spectra of particles at the exit of the accelerator, the transverse beam characteristics, etc. Optimization was carried out for the drift tubes accelerator.

TUPPB024

Development of the Object-oriented Program in C ++ for Simulation of Beam Dynamics in Accelerator Injection Systems

injection, simulation, controls, emittance

364

S.A. Kozynchenko
St. Petersburg State University, St. Petersburg, Russia

At present, more and more attention is paid to the design and creation of accelerator systems for precision beams. Their injection systems in many aspects determine the output characteristics of the beam, so the questions of the design of such systems are of great importance. In such cases both simulation and optimization of beam dynamics in electromagnetic fields close to real may be necessary. In this paper the program for simulation and optimization of beam dynamics in injection systems is considered, which at the same time allows the choice of parameters of the accelerating-focusing system. This permits designing the injection system during optimization process, taking into account the required output characteristics of the beam. The given program is based on Win 32 API dialog boxes and is developed in standard C++, using parallel programming tools based on the MPI-1.

WEPPC009

Using Genetic Algorithms for Electrode Shape Optimization in Accelerators with RF Focusing

simulation, linac, acceleration, controls

461

A.V. Samoshin, K.A. Aliev, S.M. Polozov
MEPhI, Moscow, Russia

The drift tubes shape choice which provides the require distribution of the spatial harmonics amplitudes of RF field is an important problem in the design of RF focusing accelerators. It is necessary to have various relationships of the main (accelerating) and the first (as main focusing) harmonics of RF field for different types of accelerators. High order harmonics should be negligible for accelerators with an external focusing, and this ratio should be E1/E0 = 3-5 for the efficient operation of the axially symmetric RF focusing accelerator. Thus, the distribution and harmonic amplitude's ratios at the accelerator axis which provides stable beam dynamics are always known. The drift tubes shape study problem cannot be solved directly by ordinary methods because of unknown boundary conditions belongs to a class of ill-posed problem. At present, this problem can be solved by using genetic algorithms (GA). For this purpose, the electrode shape will be represent as the polynomial function, and then solve the Laplace equation with boundary conditions of Dirichlet and Neumann. The necessary electrodes shape can be quickly and easily simulated using the adaptive search.

WEPPC024

Design, Simulation and Optimization of a Solenoid for ES-200 Electrostatic Accelerator

solenoid, simulation, target, proton

498

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

Solenoids have important role in focusing the beam in drift tube of charge particle accelerators. In order to optimize the beam current in ES-200, an electrostatic proton accelerator at Shahid Beheshti University, design and simulation of a suitable solenoid has been performed. Using CST Studio package, simulation results has been validated in comparison with theoretical formula. According to the results we optimized the design using CST to have minimum beam current on drift tube.

WEPPC038

RF Power and Control Systems for Phased Dipoles Array System for Hyperthermia

dipole, controls, electromagnetic-fields, site

524

A.M. Fadeev, V.N. Belyaev, A.A. Blinnikov, S.M. Polozov
MEPhI, Moscow, Russia
E.A. Perelstein
JINR, Dubna, Moscow Region, Russia

Cylindrical array of independently phased dipoles is suggested for hyperthermia of deep-situated tumors as a kind of treatment of cancer coupled with other methods such as radiation therapy and chemotherapy. It was proposed to focus the maximum of electromagnetic field at the site of tumor to produce high efficiency heating of tumor and to prevent overheating of surrounding healthy tissues. That's why we use system of independently fed dipole antennas. The operating frequency is 150 MHz. The independent feeding permits us to focus electromagnetic field producing by phased array in desirable area by means of changing of amplitudes and phases of each dipole. The RF power system schematic layout for 8 independently phased dipole antennas is presented. The control system of RF power system elements is considered. The software developing to provide choosing amplitude's and phase's values of dipoles are discussed.

WEPPC056

Improving of Uniformity of the Electron-Beam Treatment of Materials by ELV Accelerators

electron, radiation, controls, scattering

557

D.A. Kogut, S. Fadeev, N.K. Kuksanov
BINP SB RAS, Novosibirsk, Russia

The problem of the absorbed dose distribution during the EB treatment by ELV accelerator is considered. The value of the absorbed dose is determined by the speed of scanning electron beam along the accelerator exit window (i.e. the movement across the conveyor). It is determined both by the shape of scanning current and by the geometry of scanning magnets. A simple way to improve the dose distribution near the edges of the extraction device of accelerator is suggested. It allows to provide the non-uniformity less 4%.

WEPPD038

Optimization of the Negative Hydrogen Ion Beam Injection into the Tandem Accelerator with Vacuum Insulation

ion, proton, vacuum, tandem-accelerator

623

A.N. Makarov, V.I. Aleynik, A.G. Bashkirtsev, A.S. Kuznetsov, I.M. Schudlo, I.N. Sorokin, S.Yu. Taskaev, M.A. Tiunov
BINP SB RAS, Novosibirsk, Russia

The beam of negative hydrogen ions is injected into the tandem accelerator with vacuum insulation in order to obtain high-current proton beam. To accurately direct the beam into the accelerator the magnetic focusing lenses are used. In this paper it is described the design of the special beam detector mounted in front of the first accelerating electrode and intended to measure beam profile and the current density. The results of measurements of the dependence of the current density on the power of the magnetic focusing lenses are shown. The parameters of the beam resulting in the best agreement of calculation and experiment are specified. The optimum focusing mode to inject the negative hydrogen ions into the accelerator is determined.