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• A cryo-EM with a cold-field emission gun (CFEG) was tested for single particle analysis. • GUI programs were developed for an efficient and accurate data collection. • Imaging with CFEG is beneficial to obtaining high-resolution structures by single-particle cryo-EM. A new cryo-EM system has been investigated for single particle analysis of protein structures. The system provides parallel illumination of a highly-coherent 300 kV electron beam from a cold-field emission gun, and boosts image contrast with an in-column energy filter and a hole-free phase plate. It includes motorized cryo-sample loading and automated liquid-nitrogen filling for cooling multiple samples. In this study, we describe gun and electron beam characteristics, and demonstrate the suitability of this system for single particle reconstructions. The performance of the system is tested on two examples, a spherical virus and apoferritin. GUI programs have also been developed to control and monitor the system for correct illumination, imaging with less ellipticity and steady magnification, and timing of flashing and liquid-nitrogen filling. These programs are especially useful for efficient application of the system to single particle cryo-EM. [ABSTRACT FROM AUTHOR]

A series of Zn1−xCoxSe (x = 0, 0.025, 0.050, 0.075, and 0.100) films using were evaporated (thickness of 1 μm) using electron beam gun. The effect of Co doping on the structural, optical, and magnetic properties has been investigated. X‐ray diffraction studies confirm formation of zinc blend structure for all Zn1−xCoxSe films. The crystallite size increases and the lattice strain decreases with the increase in Co content. The elemental constituents were characterized by energy dispersive X‐ray. Optical studies showed an increase in refractive index and a decrease in energy gap with the increase in the cobalt doping. The dispersion of the refractive index has been analyzed in terms of the Wemple‐DiDomenico single oscillator model. The oscillator parameters including the single oscillator energy (Eo), the dispersion energy (Ed), and the static refractive index (n0) were estimated. Magnetization measurements via vibrating sample magnetometer showed a hysteresis loop and confirmed room‐temperature ferromagnetism in Co‐doped ZnSe films. [ABSTRACT FROM AUTHOR]

We present the design and beam dynamics analysis of a Transmission Electron Microscope illumination system. A LaB 6 emitter is used as a cathode/source with an emissive surface area of diameter 50 μm generating fixed emission current of 5 mA which is biased by −300 V with Wehnelt electrode. The gun is comprised of five electrostatic lenses in-between the focusing and anode electrodes to accelerate and focus the beam with integrated energy of 160 keV in the post anode region with diameter around 228 μm. Finally, the beam is focused using the condensed electro-magnetic lenses of field strengths 183 mT and 331 mT, respectively to spot size 1.8 μm in the post-lens position. The obtained focal spots are largely symmetric along the two transverse directions. The illumination system geometry offers full beam collimation control. The study provides a theoretical basis for the structure and optics design of the Transmission Electron Microscope. • The design, simulation and analysis of integrated illumination system of the TEM have been discussed for the study of beam dynamics first time in the literature. • The method and design of a symmetric small size probe and its transportation successfully has been obtained. • The illumination system geometry offers full beam collimation control, making it suitable for electron diffraction studies. [ABSTRACT FROM AUTHOR]

Copyright of Electrometallurgy Today / Sovremennaya Elektrometallurgiya is the property of International Association Welding (Paton Publishing House) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The thermionic electron gun is one of essential parts of electron accelerators and vacuum tubes. For electron beam generation it is basically configured by cathode, anode and it can have control electrode. In common electron guns, beam current is typically controlled by the bias voltage on the Wehnelt electrode. To deeply study the control mechanism of electron beam current, a three-dimensional model of a 60 kV/6 kW thermionic electron gun is established and the simulation of electric field distribution with CST software is shown in this paper. The particle tracking model is used to track the movement of emitted electrons and the quantitative relationship between beam current and bias voltage is established. Results show that electron beam current is inversely proportional to the bias voltage within a certain range. As the bias voltage increases, the electric field distribution in electron gun changes and the equipotential line of accelerating voltage moves towards the emitting surface of cathode, therefore the Effective Emitting Area (EEA) of cathode decreases and, accordingly, the beam current also decreases. Besides, when the bias voltage is fixed, fluctuations of the accelerating voltage cause fluctuations of the beam current, which is especially severe when the beam current is small. Graphical abstract Image 1 Highlights • Beam current control mechanism in the thermionic electron gun is simulated. • Beam current is inversely proportional to the bias voltage within a certain range. • The bias voltage adjusts beam current by changing the effective emitting surface. • Beam current with small value is more affected by high voltage fluctuations. [ABSTRACT FROM AUTHOR]

In this paper, a stacked dual beam electron gun and the associated electron optical system are proposed. The stacked dual beam electron gun includes two compact focusing electrodes which help to achieve dual sheet beams. As an application of this dual beam electron gun, a 340 GHz integrated dual beam traveling wave tube (TWT) based on the staggered dual vane slow-wave structure (SWS) is also put forward. In order to reduce the length of the TWT, a novel input/output coupler is introduced. The overall transmission characteristics of the SWS structure together with the input/output couplers show a wide bandwidth covering a frequency range of 306 GHz to 360 GHz. Based on the parameters obtained for the integrated TWT, a stacked dual-beam electron gun with dual focusing electrodes is designed to achieve a beam current of 43 mA, a beam voltage of 21.4 kV, and a cross-sectional size of each beam of 0.3 mm × 0.08 mm. A uniform magnetic field of 0.52 T is utilized to focus the dual electron beams, and a beam transmission efficiency of 97.1% is achieved over a length of 50 mm. Finally, particle in cell simulation results show that the integrated dual-beam TWT can generate an output power of 5 W over the frequency range of 315 GHz to 350 GHz, with the maximum output power of 24.5 W at 330 GHz. [ABSTRACT FROM AUTHOR]

A magnetic-focused X-band traveling wave tube (TWT) based on carbon nanotube (CNT) cathode is presented. The CNT TWT has a simple structure of the electron gun, consisting of a CNT emitter electrode and a ring-shaped anode, with no metallic mesh extracting electrode, nor electrostatic focusing electrode. The field emission electrons are extracted directly by the ring-shaped anode, while the electron beam focusing is realized by an extra magnetic field. Apart from the CNT electron gun, the TWT mainly has a high-frequency interaction circuit and a collector. All these components are totally immersed in a uniform axial magnetic field, and thus, electrons are confined by the Lorentz force during their traveling process from the cathode surface toward the collector. The fabricated CNT TWT was tested in a superconducting system providing a uniform axial magnetic field. The dc mode testing showed about 86% of the emission electrons can reach collector, which is better than a common gate-controlled CNT electron gun. [ABSTRACT FROM AUTHOR]

• A near ambient pressure photoemission electron microscope (NAP-PEEM) has been successfully developed; • Concepts of two-stage accelerating electric field and three-stage differential pumping have been adopted in combination with construction of a NAP cell; • High resolution PEEM imaging can be performed in near ambient pressure gases (> 1 mbar) and at varied temperatures; • Near ambient pressure low energy electron microscopy (NAP-LEEM) is feasible using the same electron lens system combined with an electron gun; Photoemission electron microscopy (PEEM) is a powerful surface technique for dynamic imaging of surface processes while PEEM studies have been performed under ultrahigh vacuum or high vacuum conditions. Here we report on a near ambient pressure PEEM (NAP-PEEM) instrument, which enables high resolution PEEM imaging in near ambient pressure (> 1 mbar) gases over a wide temperature range (150 – 1200 K). Installed with an electron gun near ambient pressure low energy electron microscopy (NAP-LEEM) can be achieved as well. The success of this new NAP-PEEM/LEEM instrument relies on the following key design concepts. First, a two-stage accelerating electric field consisting of a low field region between sample and intermediate electrode ("nozzle") and a high field between nozzle and objective lens. Second, a three-stage differential pumping system allowing a near ambient pressure atmosphere at the sample surface while ultrahigh vacuum maintained in the imaging lens systems. Third, a unique NAP cell with gas inlet/outlet, light illumination, sample cooling/heating, and precise sample positioning. The new technique will have important applications in surface catalysis, thin film growth, and energy conversion devices under nearly realistic working conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Promising application for atmospheric pressure ionisation in IMS and MS. • The Atmospheric Pressure Electron Gun (APEG) can replace β-emitter-based ion sources. • Deposition of thin gold films on the membranes improves the APEG performance. • Improvement of the APEG characteristics in comparison to earlier studies. Abstract In this work, we present the results of an experimental study focused on characterisation of an electron gun designed for atmospheric pressure ionisation - Atmospheric Pressure Electron Gun (APEG). The APEG generates electrons with energies of several keV and could be used as replacement for β-radiation-based ionization sources for Atmospheric Pressure Ionisation (API) in Ion Mobility Spectrometry (IMS) or Mass Spectrometry (MS). In present work we have used Si 3 N 4 membranes with thicknesses of 100 and 150 nm as vacuum–atmosphere separators. For different initial electron energies we have measured electron currents, electron energy distribution functions, and electron energy after the transmission through the membrane. We have also tried to improve the electron transmittance characteristics of the APEG by modification of the membranes by deposition of thin gold films (2.5 to 10 nm), with only the 2.5 nm film achieving an improvement. Finally, we have investigated performance of APEG in air at atmospheric pressure achieving ion currents from 2.5 to 4 μA for 10 keV electrons and found similar thresholds for electron penetration in both the positive and the negative mode of 2.6 and 3.4 kV using the 100 and 150 nm membranes, respectively. [ABSTRACT FROM AUTHOR]

The nondominated sorting genetic algorithm II and the electron optics simulator were combined to form a multiobjective optimization design tool for electron optics systems of traveling-wave tubes. After determining the objective functions that vary with the macroscopic electrical parameters that need to optimize the electron optics system, the optimization tool is capable of obtaining the optimal solution set automatically. Then, the microscopic electron trajectories of the individuals in the optimal solution set are analyzed to get the final scheme. In the collector optimization, the maximum collector efficiency and the minimum back-streaming current are used as optimization goals. While for the demonstrated electron gun, the maximum waist position is set to be the optimization goal, together with constraints of emitting current and beam waist radius. After analyzing the energy density distribution on the collector inner surface or the laminar flow of the electron gun, the final scheme is determined from the optimal solution set. [ABSTRACT FROM AUTHOR]

We present a newly designed 30 kV pulsed electron gun for ultrafast electron diffraction suited for pump-probe setups driven by femtosecond laser pulses. The electron gun can be operated both in transmission and reflection geometry. A robust design with a back illuminated Au photocathode, extraction fields of 7.5 kV/mm, and a magnetic focus lens ensures reliable daily use. Magnetic deflectors allow for beam alignment and characterization. Focusing of the UV pulse on the photocathode results in a small source size of photoemitted electrons and thus a high transverse coherence length of more than 50 nm in diffraction. A low difference of ΔE = 0.1 eV between the work function of the 10 nm Au photocathode and photon energy of the frequency tripled UV laser pulses results in an instrumental temporal resolution of 330 fs full width at half maximum. This resolution is discussed with respect to the number of electrons per pulse. [ABSTRACT FROM AUTHOR]

The design of a hollow electron beam (HEB) electron optics system for a 10-kW Ka-band extended interaction klystron is presented. To lower the maximum cathode current density and realize the fast switch of the current emission, an HEB with two focus electrodes (FEs) is chosen, which attains to a high area compression ratio of over 100. A 25-kV, 2.5-A beam is produced by a curved spherical segment cathode with the area of 0.321 cm2 and an average beam loading of 8 A/cm2, namely, the high area compression ratio is necessary to reduce the cathode emission current density. The HEB with an area compression ratio of 105 can propagate 40 mm long with good laminarity confined by a 0.7-T uniform magnetic field. The beam current can be quickly shut off when the voltages of the FEs are biased to −4100 V. The results were simulated with two simulation codes: EGUN and OPERA 3-D. A sensitivity analysis with respect to critical parameters such as the displacement of FE1 and FE2 in the radial direction is provided. The simulation results of OPERA 3-D/SCALA and EGUN show an excellent agreement. [ABSTRACT FROM AUTHOR]

Abstract A new concept of pulse radiolysis based on a photoinjector, which can synchronously offer femtosecond (fs) pump electron beams and intense Terahertz (THz) probe pulses, is proposed and studied in this paper. The two electron beams are generated in the radio-frequency (rf) electron gun by illuminating the photocathode with two laser pulses, then compressed and accelerated in two linear accelerators respectively. By applying the brake-applied velocity bunching bunch compression method, a few hundreds of fs electron beams with nano-Coulomb (nC) bunch charge can be obtained. The front beam can generate THz pulse with MW peak power for THz probe, and the rear beam is used to pumping the radiation induced phenomena. This new concept pulse radiolysis scheme provides a promising way for high time resolution pump-probe experiments with a novel experimental methodology. Highlights • A femtosecond pulse radiolysis with high intensity Terahertz probe is proposed. • Providing a promising way for pump-probe experiments. • Electron beam has a femtosecond length with a nano-Coulomb charge. • THz radiation is broadband with a MW peak power. • This scheme is very compact and has a high time resolution. [ABSTRACT FROM AUTHOR]

An algorithm of calculation of the focal distance of a hollow conical electron beam, formed by high voltage glow discharge electron guns, as well as the calculation of the diameter and thickness of a focal ring of such a beam, are considered in the article. The proposed algorithm is based on the model of free moving of electrons in the anode plasma and formed on the base of the laws of electron optics with using the methods of discrete mathematics and minimax analysis. Obtained simulation results allow to find the important regularities, which characterized the dependencies of focal parameters of a hollow conical electron beam, formed by the high voltage glow discharge electron guns, on the constructive parameters of electrodes’ system of the electron gun. [ABSTRACT FROM AUTHOR]

Abstract Distributed X-ray sources provide a solid foundation for the invention of new-generation computed tomography (CT). This study proposes a novel multi-focal spot electron gun scheme for distributed X-ray sources. The source in this study uses a dispenser cathode as the electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflecting. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. It consists of two identical half-rectangle opening electrodes by adjusting the potential of the two electrodes to control the trajectory of the electron beam and then obtain multi-focal spots on the anode target. The number of X-ray sources in the distributed source is limited by the amount of cathodes. The multi-focal spot electron gun can break this limitation and provide more possibilities and options for distributed X-ray sources and stationary CT. Experimental results reflect the excellent repeatability of the multi-spot electron gun. The dynamic effective focal spot sizes of the deflected (deflected amplitude, 10.5mm) and non-deflected electron beams at full with half max (FWHM) are 1.30mm × 0.60mm and 1.15mm × 0.55mm, respectively (anode voltage, 160kV; beam current, 30 mA). [ABSTRACT FROM AUTHOR]

A high power Ku-band TE01 mode gyrotron traveling wave tube amplifier (gyro-TWT) is designed and experimented in this paper. The emphasis is put on the gyro-TWT with a high average power. In the design process, a low average velocity spread magnetron injection electron gun and a wideband multichannel TE01 mode input coupler are adopted. At the same time, a high average power curved collector is also applied. To suppress the potential gyro-backward wave oscillator interactions, a new type lossy ceramic rings and lossy ceramic pieces hybrid loaded structure is used in the high-frequency interaction circuit of gyro-TWT. In hot test, the developed Ku-band TE01 mode gyro-TWT is driven by a 70-kV 23-A helical electron beam and produce a ~31.5 kW maximum saturated output average power at 16.2 GHz, corresponding to a saturated peak power of ~450 kW (7% duty ratio), a saturated gain of ~40.5 dB, an efficiency of ~28%. The measured 3-dB bandwidth is ~2.1 GHz. The gyro-TWT is found to be zero-drive stable at these operating points. [ABSTRACT FROM AUTHOR]

The results of the performance tests of a three-layer foil separator for a high-current electron gun of an ELA excimer laser are presented. The separator consisted of two layers of thin titanium foil with a polyimide film between them. Such a composition withstood 5630 electron beam pulses with duration of 80 ns and an energy density per pulse of about 9 J/cm2. In this case, the polyimide film (Dupont Kapton polyimide film) with a thickness of 38 μm was irradiated with a dose of 1 GGy. The initial and induced absorption of this film was measured in the range from 20 to 0.4 μm. The mechanical tensile strength of the irradiated film decreased by 17 times. [ABSTRACT FROM AUTHOR]

Abstract Many applications, such as high-data-rate wireless communications, spectroscopy, high-resolution radar, biomedical imaging, security, etc. require compact high-power sources of sub-THz radiation. Traveling wave tube (TWT) amplifiers are the most promising candidates for such sources combining 10–100 W power and wide bandwidth. Here we present the results of design and simulation of a 0.2-THz TWT with a grating slow-wave structure (SWS) and electron-optical system (EOS) with a converging sheet electron beam. The designed EOS provides substantial improvement of the amplifier performance as compared with the EOS with straight beam immersed in a uniform magnetic field. In particular, it facilitates beam focusing and allows reduce of the focusing magnetic field and cathode current density. The latter allows increase of lifetime and makes possible operation in a continuous-wave mode. In addition, decrease of the beam thickness allows reduce of the beam tunnel height accordingly, which leads to nearly 2.5-times increase of the Pierce coupling impedance resulting in increase of gain and decrease of the required driving power. The simulation predicts small-signal gain over 30 dB in 180–200 GHz frequency band and over 80 W saturated power. [ABSTRACT FROM AUTHOR]

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: For scanning particle beam therapy, interference between scanning patterns and interfield organ motion may result in suboptimal dose within target volume. In this study, we developed a simple offline correction technique for uniform scanning proton beam (USPB) delivery to compensate for the interplay between scanning patterns and respiratory motion and demonstrate the effectiveness of our technique in treating liver cancer. Methods: The computed tomography (CT) and respiration data of two patients who had received stereotactic body radiotherapy for hepatocellular carcinoma were used. In the simulation, the relative beam weight delivered to each respiratory phase is calculated for each beam layer after treatment of each fraction. Respiratory phases with beam weights higher than 50% of the largest weight are considered "skipped phases" for the next fraction. For the following fraction, the beam trigger is regulated to prevent beam layers from starting irradiation in skipped phases by extending the interval between each layer. To calculate dose‐volume histogram (DVH), the dose of the target volume at end‐exhale (50% phase) was calculated as the sum of each energy layer, with consideration of displacement due to respiratory motion and relative beam weight delivered per respiratory phase. Results: For a single fraction, D1%, D99%, and V100% were 114%, 88%, and 32%, respectively, when 8 Gy/min of dose rate was simulated. Although these parameters were improved with multiple fractions, dosimetric inhomogeneity without motion management remained even at 30 fractions, with V100% 86.9% at 30 fractions. In contrast, the V100% values with adaptation were 96% and 98% at 20 and 30 fractions, respectively. We developed an offline correction technique for USPB therapy to compensate for the interplay effects between respiratory organ motion and USPB beam delivery. Conclusions: For liver tumor, this adaptive therapy technique showed significant improvement in dose uniformity even with fewer treatment fractions than normal USPB therapy. [ABSTRACT FROM AUTHOR]

Vigorously developing nuclear power is the main development direction of current renewable energy. In the nuclear environment, in order to avoid nuclear radiation damage to maintenance personnel and improve the efficiency of nuclear reaction, it is necessary and urgent to realize automatic replacement of vulnerable parts in the electron gun. As the key equipment for the generation and control of nuclear reactions in nuclear reactors, electron guns have been widely used in nuclear power plants of traveling wave reactors. However, the “high-voltage conductive ring” in electron guns is a vulnerable part. It is likely to cause nuclear reactor accidents when the vulnerable part is damaged. Automatic replacement of vulnerable parts is an important part of the entire maintenance equipment. Considering the entire maintenance equipment and the working environment, an innovative design process for vulnerable parts replacement is established. Under the guidance of the process, in order to ensure the continuity of a series of maintenance actions, the technical contradiction resolution theory is first used to conduct the overall analysis of the general direction to obtain the design layout. Then, the contradiction resolution theory and the object-field model analysis are utilized to get and improve the detailed design of the device mechanism. The theory of TRIZ can help us to get the overall mechanical structure design that meets the engineering requirements. The device is designed with a replacement part adjustment scheme to ensure the completion of the maintenance actions. Furthermore, the design provides a solution to the possible jamming phenomenon in the automatic maintenance process and achieves the maximum use efficiency of the storage and replacement of vulnerable parts. [ABSTRACT FROM AUTHOR]

The space-charge field at the cathode limits the current density extracted from particle sources such as photoinjectors. For a long time, the maximum current has been estimated by using the classical Child-Langmuir law, which is derived with an assumption inconsistent with the conditions of modern laser-driven electron guns. Here, we introduce a theoretical model that accurately accounts for space-charge effects in transversely confined particle beams emerging from photocathodes. The model enables us to (i) determine the maximum current density extractable from the photocathode for an arbitrary cathode radius, (ii) reveal its dependence on the transverse profile of the particle beam, and (iii) predict its upper limit for structured beams such as the ones produced by surface-plasmon resonance-enhanced photocathodes. [ABSTRACT FROM AUTHOR]

Abstract The AXSIS project (Attosecond X-ray Science: Imaging and Spectroscopy) aims to develop a THz-driven compact X-ray source for applications e.g. in chemistry and biology by using ultrafast coherent diffraction imaging and spectroscopy. The key components of AXSIS are the THz-driven electron gun and THz-driven dielectric loaded linear accelerator as well as an inverse Compton scattering scheme for the X-rays production. This paper is focused on the prototype of the THz-driven electron gun which is capable of accelerating electrons up to tens of keV. Such a gun was manufactured and tested at the test-stand at DESY. Due to variations in gun fabrication and generation of THz-fields the gun is not exactly operated at design parameters. Extended simulations have been performed to understand the experimentally observed performance of the gun. A detailed comparison between simulations and experimental measurements is presented in this paper. [ABSTRACT FROM AUTHOR]

Abstract The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapor plasma cell to create strong wakefields allowing sustained electron acceleration. The electron beam to probe these wakefields is created by an electron accelerator consisting of an rf-gun and a booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The booster structure should accelerate the electrons to 16 MeV. The electron line includes a series of diagnostics (pepper-pot, BPMs, spectrometer, Faraday cup and screens) and an optical transfer line merges the electron beam with the proton beam on the same axis. The installation of the electron line started in early 2017 and the commissioning will take place at the end of 2017. The first phase of operation is called RUN1. After the long shutdown of LHC a second phase for AWAKE is planned starting 2021 called RUN2. In this phase the aim is to demonstrate the acceleration of high quality electron beams therefore a bunch length of the order of 100 fs rms is required corresponding to a fraction of the plasma wavelength. The AWAKE collaboration is studying the design of such an injector either based on classical rf-gun injectors or on laser wake-field acceleration. The focus for the RF accelerator is on a hybrid design using an S-band rf-gun and x-band bunching and acceleration cavities. The layout of the current and the future electron accelerator and transfer line, including the diagnostics will be presented. Highlights • Electron source for the AWAKE experiment at CERN. • Design of an ultra-short bunches electron source. • Optical and electrical diagnostics for the AWAKE experiment at CERN. [ABSTRACT FROM AUTHOR]

Abstract The concept of the electron multi-beam linear accelerator EVT invokes aspects of a two-beam accelerator. Here, effective transformation of several drive beams energy into the high-voltage accelerated beam energy takes place. It combines an RF generator and essentially an accelerator within the same vacuum envelope. Acceleration occurs in inductively-tuned cavities. The ratios between values of RF beam currents and their voltages are similar to ratios for an electric transformer that allows to designate this device as an Electron Voltage Transformer (EVT). The EVT accelerator properties prove to be true by the example of numerical simulations of two-stage EVT operating in S-band with a 60 kV gun and generating a 1 A, 4.5 MV beam at its output, having efficiency of 25% is presented. ©2001 Elsevier Science. All rights reserved. [ABSTRACT FROM AUTHOR]

Highlights • KoHLT-EB (Korea Heat Load Test facility with Electron Beam gun) is operated for the performance testing of PFCs in Korea. • Various tungsten mockups were fabricated by HIP (Hot Isostatic Pressing) and VPS (vacuum plasma spray) coating technique. • A thermal fatigue test was performed to validate manufacturing technology, thermo-hydraulic performance and design validation. Abstract KoHLT-EB (Korea Heat Load Test facility with Electron Beam gun) is operated for the performance qualification testing of the plasma facing components (PFC), ITER first wall (FW), ITER TBM (Test Blanket Module) FW, and DEMO PFCs in Korea. A thermal fatigue test shall be performed on the fabricated mockups to validate manufacturing technology, thermo-hydraulic performance and design validation using high heat load testing. The test parameters are defined along with numerically simulated conditions. For the high heat flux testing, various mockups were fabricated by each bonding technique, such as HIP (Hot Isostatic Pressing), vacuum plasma spray (VPS) coating technique. Each fabricated mockup was installed inside the vacuum chamber of KoHLT-EB, and thermo-hydraulic performance tests and thermal fatigue tests were performed to qualify the mockups specification and bonding techniques. [ABSTRACT FROM AUTHOR]

Abstract: The dynamics of the electron beam in a C-band linear accelerator, a bremsstrahlung source with a boundary energy switched between 2.5 MeV and 6 MeV, which is intended for stereotactic and three-dimensional conformal radiotherapy in static and rotational modes, was calculated. [ABSTRACT FROM AUTHOR]

Features a study that developed an approach for controlling the electron trajectories in a relativistic electron beam diode which is based on appropriately contouring an externally generated, axial magnetic field. Technique for designing low-current, electrostatically focused electron guns; Analysis of the diode geometry to illustrate the solution technique; Assumptions used in the analysis.

Presents a study which measured the temporal evolution of beam emittance and beam brightness from a field-emission electron gun. Information on the technical applications of relativistic electron beams; Details of the experimental techniques used; Impact of repetitive pulsing of the electron gun on electron beam brightness.

Presents a study that described the design of an electron gun and gyroklystron circuits. Features of an ideal electron gun; Effect of finite magnetic transitions on an electron gun; Comparison of the design of two gyroklystron circuits.

Describes the electro-optical simulation of rotationally symmetric triode electron guns. Importance of computer aided design in the design of electron optical devices; Calculation of potential fields and trajectories; Development of a computer code for experimental verification.

Deals with a study which obtained molybdenum disilicide under ultrahigh vacuum conditions through electron gun evaporation of molybdenum on heated monocrystalline silicon substrate. Experimental procedures; Assessment on the relative orientation of tetragonal silicide; Epitaxial relationships deduced from indexation.

Presents a study which developed a high brightness electrostatically focused field emission gun for use in free electron laser. Experimental arrangement; Results; Comparison of results with previous studies.

Focuses on a study that examined the strain behavior of polycrystalline niobium (Nb) thin films deposited onto oxidized silicon substrates using an electron gun in a high vacuum system. Status of the sign and magnitude of strain in Nb thin films; Factor responsible for the increase in the use of refractory thin films as electrode device materials; Significance of the reduction of strain level in refractory films.

Presents information on the performance of materials processing to the applications of a pulsed cold cathode electron gun. Information on the model of the cold cathode electron gun discharge; Details on the material interactions in relation to the electron beam; Conclusion of the experiment.

Presents information on a study that accomplished deposition of silicon dioxide thin films on silicon, germanium, and glass substrates by electron gun evaporation under various experimental conditions. Experimental procedure; Results and discussion on the study; Conclusion.

Presents a study which detailed the preparation of silicon dioxide thin films by electron-gun evaporation under various deposition conditions. Way in which the residual stresses in SiO[sub2] films were determined; Characteristics of the films under deposition conditions; Types of stresses.

Examines the structure and mechanisms of the plasma-anode electron gun. Background on high-voltage electron guns as laser sources; Operating principles; Electron-beam profile and temperature; Information on the gun's cold-cathode electron source.

Focuses on the observation of a charge limit for semiconductor photocathodes. Description of the photocathode electron gun; Effect of the titanium:sapphire laser illumination on the photocathode; Comparison between the saturation curves for circular polarized light and line polarized light.

This paper presents the design studies of the common input and output system of a continuous wave (CW), V-band gyrotron at second harmonic for plasma diagnostics application. Two different designs are carried out with design 1 operating at TE 7 , 3 mode having same geometrical parameters for dual power operation of 100 kW and 200 kW and design 2 operating at TE 8 , 3 mode has same geometry that can support dual power operation of 100 kW and 200 kW respectively. The selection of the initial design parameters has been done using our in-house computer code Gyrotron Design Studio Second Harmonic Version 2020 (GDS2H-2020). The electron guns along with magnetic guidance systems are designed to generate electron beam with the required beam parameters using software package EGUN. The design and optimization of the Non-Linear Taper (NLT), Quasi-Optical Launcher (QOL) and RF window are carried out for both the designs. NLTs are optimized for maximum transmission efficiency of the desired modes using Computer Simulation tool (CST). QOLs are designed for converting the operating modes into Gaussian-like mode using commercial software packages Launcher Optimization Tool (LOT) and SURF3D. The designs of the single-disk RF window for high-power output beam extraction are performed using CST. • Common input-output system of V-band second harmonic gyrotron for plasma diagnostics. • Two different designs with same geometrical parameters for dual power operation. • Input system comprises of electron guns along with magnetic guidance systems. • Output system consists of Non-Linear Taper, Quasi-Optical Launcher and RF window. [ABSTRACT FROM AUTHOR]