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Electron Beam Control and Diagnostics for Advanced Technologies
Zobač, Martin ; Kolařík, Vladimír (referee) ; Průša, Stanislav (referee) ; Lencová, Bohumila (advisor)
The thesis deals with problems of control and diagnostics of electron beam technological devices which use electron beam for localised intensive heating of a material. A brief description of the electron beam welder MEBW-60/2 is included; the author has participated on its development and implementation. Main topics are the analysis of deflection system properties and the measurement of current distribution of the beam (so-called beam profiles). Geometrical aberrations, hysteresis, stability and dynamics of a single-stage magnetic x-y deflection system are described. Suitable measurement procedures and correction methods are introduced. Methods of transverse and longitudinal beam profile acquisition is presented using successive sampling of the local current density of the beam by a modified Faraday cup. The data processing and evaluation of characteristic beam parameters are shown. The presented methods were verified by fourteen experiments using the electron beam welder. The methods have proven to be useful in practical evaluation of the device properties.
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Electron Beam Control and Diagnostics for Advanced Technologies
Zobač, Martin ; Kolařík, Vladimír (referee) ; Průša, Stanislav (referee) ; Lencová, Bohumila (advisor)
The thesis deals with problems of control and diagnostics of electron beam technological devices which use electron beam for localised intensive heating of a material. A brief description of the electron beam welder MEBW-60/2 is included; the author has participated on its development and implementation. Main topics are the analysis of deflection system properties and the measurement of current distribution of the beam (so-called beam profiles). Geometrical aberrations, hysteresis, stability and dynamics of a single-stage magnetic x-y deflection system are described. Suitable measurement procedures and correction methods are introduced. Methods of transverse and longitudinal beam profile acquisition is presented using successive sampling of the local current density of the beam by a modified Faraday cup. The data processing and evaluation of characteristic beam parameters are shown. The presented methods were verified by fourteen experiments using the electron beam welder. The methods have proven to be useful in practical evaluation of the device properties.
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Diagnostic Lithium Beam System for COMPASS Tokamak
Háček, P. ; Weinzettl, Vladimír ; Stöckel, Jan ; Anda, G. ; Veres, G. ; Zoletnik, S. ; Berta, M.
The COMPASS tokamak has been re-installed in IPP Prague after its transport from Culham in UK. A Diagnostic Lithium Beam system is being developed for COMPASS tokamak. Its main goal is to provide edge density (Beam Emission Spectroscopy) and edge plasma current (Atomic Beam Probe) measurements to address the scientific programme focused on H-mode and pedestal physics. It features several newly designed and developed parts, including improved emitter and neutralizer. Atomic Beam Probe is an innovatory diagnostic for measurement of poloidal magnetic field and plasma current fluctuations in the plasma edge. Currently, the system is connected to tokamak (August 2011) and first experiments with plasma were performed. The system still undergoes vacuum, neutralization and high voltage testing. This article reviews the concept and current state of the Lithium Beam diagnostic for COMPASS and provides its first test results.
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Atomic Beam Probe Diagnostic for COMPASS Tokamak
Háček, Pavel ; Weinzettl, Vladimír ; Stöckel, Jan ; Anda, G. ; Veres, G. ; Zoletnik, S. ; Berta, M.
The COMPASS tokamak has been re-installed in IPP Prague after its transport from Culham in UK. New diagnostic tools are under development to address the scientific program focused on H-mode and pedestal physics. Atomic Beam Probe (ABP) is an innovatory diagnostic for measurement of poloidal magnetic field and plasma current fluctuations in the plasma edge. It is planned to be an extension of the beam emission spectroscopy system by collecting the lithium ions stemming from beam ionization. In the first approximation, ionization is proportional to the local plasma density. The poloidal magnetic field moves the ions toroidally. Therefore, the two-dimensional poloidal-toroidal measurement of the ion current in the exit port reveals information on both the density and magnetic field profiles, thereby also on the edge current profile. This article reviews the concept of the ABP diagnostic and the status of its installation on the COMPASS tokamak.
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