RUPAC2012 - List of Keywords (electromagnetic-fields)

Paper	Title	Other Keywords	Page
TUZCH02	Mathematical Modeling and Optimization of Beam Dynamics in Accelerators	rfq, controls, focusing, quadrupole	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]

FRXOR01	Technique and Instrumentation For Bunch Shape Measurements	electron, target, linac, ion	181
	A. Feschenko RAS/INR, Moscow, Russia
	Bunch shape is one of the most important, interesting but difficult to observe characteristics of a beam in ion linear accelerators. Different possibilities of bunch shape measurements are considered but the emphasis is put on the Bunch Shape Monitors (BSM) developed in INR RAS. The operation of BSM is based on a coherent transformation of a longitudinal structure of a beam under study into a spatial distribution of a secondary electron beam through rf scanning. BSM characteristics found both by simulations and experimentally are presented; the ultimate parameters and the limitations are discussed. Modifications of BSM are described. Some experimental results of bunch observations are demonstrated.
	Slides FRXOR01 [6.339 MB]

MOPPA002	Nonlinear Theory of Excitation of an Axially Asymmetric Wakefield in Dielectric Resonator	wakefield, electron, vacuum, acceleration	245
	K.V. Galaydych, G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine
	A nonlinear self-consistent theory of excitation of an axially asymmetric wakefield by relativistic electron bunches in cylindrical dielectric resonator with a vacuum channel for the charged particles transportation through the resonator is constructed. An excited fields are presented in the form of superposition solenoidal and potential fields. The solenoidal electromagnetic fields are presented by an expansion of the required fields into solenoidal fields of the empty dielectric resonator. The potential field is presented by the eigenfunction expansion method. The dispersion equation for determination of eigenfrequencies and the equation for eigenvalues are obtained, eigenwaves, eigenfunctions and their norms are found. For an excited fields the analytical expressions, that take into account both longitudinal and transverse dynamics of bunch particles are derived. Along with the equations of motion they provide a self-consistent description of the dynamics of generated fields and bunches. The formulated nonlinear theory allows investigating numerically the nonlinear effects such as increasing of the transverse bunch size, and head-tail beam breakup instability, which occurs if the electron bunch in the structure is misaligned.

MOPPA007	Wakefield Produced by a Small Bunch Moving in Cold Magnetized Plasma Along the External Magnetic Field	plasma, wakefield, acceleration, electron	257
	S.N. Galyamin, D.Y. Kapshtan, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: The Dmitry Zimin "Dynasty" Foundation and Russian Foundation for Basic Research (Grant No. 12-02-31258). Plasma wakefield acceleration (PWFA) is a promising tool for acceleration of charged particles to high energies at relatively small lengths. Knowledge about the structure of the electromagnetic field produced by the driver bunch in plasma plays the essential role for the realization of this accelerating scheme. Constant external magnetic field which can be used for focusing the driver bunch affects the field structure essentially because plasma acquires both anisotropy and gyrotropy. However, the electromagnetic field in the latter case has not been practically investigated until present. Here we study the field produced by point charge and small bunch moving in cold magnetized plasma along the external magnetic field. We note the singular behavior of some components of the wave field produced by point charge near the charge trajectory. We also analyze the influence of the external magnetic field and bunch size on the field components.

TUPPB026	Comparison of Matrix Formalism and Step-by-step Integration for the Long-term Dynamics Simulation in Electrostatic Fields	simulation, lattice, storage-ring, controls	370
	A.N. Ivanov St. Petersburg State University, St. Petersburg, Russia
	An approach based on matrix formalism for solving differential equations is described. Effective in sense of performance matrix formalism can be tested with less efficient, but accurate traditional algorithm of numerical simulation based on the Runge-Kutta scheme. In both cases the symplectic version of the algorithms are used. The results coincide to analytical calculations, but some disagreements have been identified. The approach implementation is demonstrated in the problem of long-term spin dynamics in electrostatic fields.

TUPPB028	Degenerate Solutions of the Vlasov Equation	simulation	376
	O.I. Drivotin St. Petersburg State University, St. Petersburg, Russia
	The report deals with degenerate solutions of the Vlasov equation. By degenerate solution we mean a distribution which have support of dimension smaller than dimension of the phase space. Well known example is the Kapchinsky-Vladimirsky (KV) distribution, when particles are distributed on the 3-dimensional surface in the 4-dimensional phase space. We use covariant formulation of the Vlasov equation developed previously*. In traditional approach, the Vlasov equation is considered as integro-differential equation with partial derivatives on phase coordinates. Covariant approach means tensor formulation. For the covariant formulation of the Vlasov equation, we use such tensor object as the Lie derivative. According to the covariant approach, a degenerate solution is described by differential form which degree is equal to the dimension of its support. Main attention is paid to the KV distribution, which is described by the differential form of the third degree. It is demonstrated that the KV distribution satisfies to the Vlasov equation in covariant formulation. It is shown, how one can set initial partical positions in the phase space to simulate that distribution. Some other distributions are also considered. This work has theoretical as well as practical significance. Presented results can be applied for description and simulation of high-intensity beam. O.I. Drivotin. Covariant Formulation of the Vlasov Equation. Proc. of IPAC 2011, San-Sebastian, Spain. http://accelconf.web.cern.ch/AccelConf/IPAC2011/papers/wepc114.pdf

WEPPC037	Cylindrical Phased Dipoles Array for Hyperthermia of Deep-Situated Tumors	dipole, simulation, radiation, radio-frequency	521
	A.M. Fadeev, V.N. Belyaev, S.M. Polozov MEPhI, Moscow, Russia E.A. Perelstein JINR, Dubna, Moscow Region, Russia
	The treatment of deep-situated malignant tumors is often a difficult problem in which the purpose is to reduce the size of completely remove a tumor by using one or more modalities. The traditional methods are: radiation therapy, chemotherapy and surgery. Hyperthermia is another method which is used alone or coupled with other methods of cancer treatment. Hyperthermia is a heating of the tumor that makes it more sensitive to chemotherapy or radiation therapy and leads to it thermal damage. Temperature range for hyperthermia treatment is from 42.5 C to 45 C. It is important to prevent heating of healthy tissues and to produce sufficient heating at the site of a deep-situated tumor. This kind of hyperthermia is called the local hyperthermia. The electromagnetic field in 100-200 MHz frequency range is optimal for heating of deep-situated tumors. The system for local hyperthermia of cancer was simulated. This system is based on cylindrical phased array consisting of multiple dipole antennas with operating frequency 150 MHz. The electric fields and specific absorption rate distributions are calculated in cut of tissue-equivalent phantom. Shown that electric field can be focused in desirable region by means of varying of amplitudes and phases of each dipole. The advantages of using combined therapy of common hyperthermia with chemotherapy or radiation therapy are discussed.

WEPPC038	RF Power and Control Systems for Phased Dipoles Array System for Hyperthermia	dipole, controls, focusing, 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.

Paper

Title

Other Keywords

Page

TUZCH02

Mathematical Modeling and Optimization of Beam Dynamics in Accelerators

rfq, controls, focusing, quadrupole

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]

FRXOR01

Technique and Instrumentation For Bunch Shape Measurements

electron, target, linac, ion

181

A. Feschenko
RAS/INR, Moscow, Russia

Bunch shape is one of the most important, interesting but difficult to observe characteristics of a beam in ion linear accelerators. Different possibilities of bunch shape measurements are considered but the emphasis is put on the Bunch Shape Monitors (BSM) developed in INR RAS. The operation of BSM is based on a coherent transformation of a longitudinal structure of a beam under study into a spatial distribution of a secondary electron beam through rf scanning. BSM characteristics found both by simulations and experimentally are presented; the ultimate parameters and the limitations are discussed. Modifications of BSM are described. Some experimental results of bunch observations are demonstrated.

Slides FRXOR01 [6.339 MB]

MOPPA002

Nonlinear Theory of Excitation of an Axially Asymmetric Wakefield in Dielectric Resonator

wakefield, electron, vacuum, acceleration

245

K.V. Galaydych, G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine

A nonlinear self-consistent theory of excitation of an axially asymmetric wakefield by relativistic electron bunches in cylindrical dielectric resonator with a vacuum channel for the charged particles transportation through the resonator is constructed. An excited fields are presented in the form of superposition solenoidal and potential fields. The solenoidal electromagnetic fields are presented by an expansion of the required fields into solenoidal fields of the empty dielectric resonator. The potential field is presented by the eigenfunction expansion method. The dispersion equation for determination of eigenfrequencies and the equation for eigenvalues are obtained, eigenwaves, eigenfunctions and their norms are found. For an excited fields the analytical expressions, that take into account both longitudinal and transverse dynamics of bunch particles are derived. Along with the equations of motion they provide a self-consistent description of the dynamics of generated fields and bunches. The formulated nonlinear theory allows investigating numerically the nonlinear effects such as increasing of the transverse bunch size, and head-tail beam breakup instability, which occurs if the electron bunch in the structure is misaligned.

MOPPA007

Wakefield Produced by a Small Bunch Moving in Cold Magnetized Plasma Along the External Magnetic Field

plasma, wakefield, acceleration, electron

257

S.N. Galyamin, D.Y. Kapshtan, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: The Dmitry Zimin "Dynasty" Foundation and Russian Foundation for Basic Research (Grant No. 12-02-31258).
Plasma wakefield acceleration (PWFA) is a promising tool for acceleration of charged particles to high energies at relatively small lengths. Knowledge about the structure of the electromagnetic field produced by the driver bunch in plasma plays the essential role for the realization of this accelerating scheme. Constant external magnetic field which can be used for focusing the driver bunch affects the field structure essentially because plasma acquires both anisotropy and gyrotropy. However, the electromagnetic field in the latter case has not been practically investigated until present. Here we study the field produced by point charge and small bunch moving in cold magnetized plasma along the external magnetic field. We note the singular behavior of some components of the wave field produced by point charge near the charge trajectory. We also analyze the influence of the external magnetic field and bunch size on the field components.

TUPPB026

Comparison of Matrix Formalism and Step-by-step Integration for the Long-term Dynamics Simulation in Electrostatic Fields

simulation, lattice, storage-ring, controls

370

A.N. Ivanov
St. Petersburg State University, St. Petersburg, Russia

An approach based on matrix formalism for solving differential equations is described. Effective in sense of performance matrix formalism can be tested with less efficient, but accurate traditional algorithm of numerical simulation based on the Runge-Kutta scheme. In both cases the symplectic version of the algorithms are used. The results coincide to analytical calculations, but some disagreements have been identified. The approach implementation is demonstrated in the problem of long-term spin dynamics in electrostatic fields.

TUPPB028

Degenerate Solutions of the Vlasov Equation

simulation

376

O.I. Drivotin
St. Petersburg State University, St. Petersburg, Russia

The report deals with degenerate solutions of the Vlasov equation. By degenerate solution we mean a distribution which have support of dimension smaller than dimension of the phase space. Well known example is the Kapchinsky-Vladimirsky (KV) distribution, when particles are distributed on the 3-dimensional surface in the 4-dimensional phase space. We use covariant formulation of the Vlasov equation developed previously*. In traditional approach, the Vlasov equation is considered as integro-differential equation with partial derivatives on phase coordinates. Covariant approach means tensor formulation. For the covariant formulation of the Vlasov equation, we use such tensor object as the Lie derivative. According to the covariant approach, a degenerate solution is described by differential form which degree is equal to the dimension of its support. Main attention is paid to the KV distribution, which is described by the differential form of the third degree. It is demonstrated that the KV distribution satisfies to the Vlasov equation in covariant formulation. It is shown, how one can set initial partical positions in the phase space to simulate that distribution. Some other distributions are also considered. This work has theoretical as well as practical significance. Presented results can be applied for description and simulation of high-intensity beam.
O.I. Drivotin. Covariant Formulation of the Vlasov Equation.
Proc. of IPAC 2011, San-Sebastian, Spain.
http://accelconf.web.cern.ch/AccelConf/IPAC2011/papers/wepc114.pdf

WEPPC037

Cylindrical Phased Dipoles Array for Hyperthermia of Deep-Situated Tumors

dipole, simulation, radiation, radio-frequency

521

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

The treatment of deep-situated malignant tumors is often a difficult problem in which the purpose is to reduce the size of completely remove a tumor by using one or more modalities. The traditional methods are: radiation therapy, chemotherapy and surgery. Hyperthermia is another method which is used alone or coupled with other methods of cancer treatment. Hyperthermia is a heating of the tumor that makes it more sensitive to chemotherapy or radiation therapy and leads to it thermal damage. Temperature range for hyperthermia treatment is from 42.5 C to 45 C. It is important to prevent heating of healthy tissues and to produce sufficient heating at the site of a deep-situated tumor. This kind of hyperthermia is called the local hyperthermia. The electromagnetic field in 100-200 MHz frequency range is optimal for heating of deep-situated tumors. The system for local hyperthermia of cancer was simulated. This system is based on cylindrical phased array consisting of multiple dipole antennas with operating frequency 150 MHz. The electric fields and specific absorption rate distributions are calculated in cut of tissue-equivalent phantom. Shown that electric field can be focused in desirable region by means of varying of amplitudes and phases of each dipole. The advantages of using combined therapy of common hyperthermia with chemotherapy or radiation therapy are discussed.

WEPPC038

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

dipole, controls, focusing, 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.