Performance of an electron gun
Electron gun for applying external gun to diode emitter region
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High Pressure Electron Gun for Electron Beam Welding and Additive Manufacturing
Electron beam welding is a premier technology for high quality welding. However, e-beam welding is viewed as very expensive method for quality results. Therefore, it is often the last choice for joining metals. U.S. Electron is developing a technology that changes the welding environment. As a result of this pursuit of technology, e-beam welding can be field deployable. U.S. Electron has received a DOE SBIR Phase I grant to demonstrate a proof of principle that the plasma cathode can be installed in an electron gun housing, generate a current and energy enough to weld stainless steel. Under this CRADA, Fermilab proposed to provide a power supply, the necessary safety expertise and the physical location for testing of the initial prototype equipment developed by U.S. Electron.
43 PARTICLE ACCELERATORS↗
Carbon nanotube electron gun
An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.
Nguyen, Cattien V.↗
Carbon Nanotube Electron Gun
An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.
Nguyen, Cattien V.↗
PROPOSAL FOR HOLLOW CATHODE ELECTRON GUN FOR ELECTRON COOLING
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Krienen, F.↗
A compact high current pulsed electron gun with subnanosecond electron pulse widths
A magnetically-collimated, double-pulsed electron gun capable of generating electron pulses with a peak instantaneous current of approximately 70 microamps and a temporal width of 0.35 ns (FWHM) has been developed. Calibration is accomplished by measuring the lifetime of the well known 2(1P)-to-1(1S) transition in helium (58.4nm) at a near-threshold electron-impact energy by use of the delayed-coincidence technique.
Khakoo, M. A.↗
Inverted Geometry Ceramic Insulators in High Voltage DC Electron Guns for Accelerators
A direct current (dc) high voltage photo-emission electron gun operating at 130 kV is utilized at the Jefferson Lab (JLab) Continuous Electron Beam Accelerator Facility to generate spin-polarized electrons for nuclear physics experiments. Over the past decade, JLab has tested and implemented inverted-geometry ceramic insulators in photoguns, connecting the cathode electrode in vacuum to the high voltage power supply using commercial high voltage cables. This contribution reports on tests performed up to 375 kV dc, implementation of inverted insulators in a 300 kV dc photogun generating magnetized electron beams, and describes plans to develop a reliable insulator-cable connector for applying 500 kV dc to a future polarized beam photogun operating reliably and without field emission at 350 kV.
Hernandez-Garcia, C.↗
The development programme of cathodes and electron guns for the Hollow Electron Lenses of the High Luminosity LHC project1
The High Luminosity LHC project (HL-LHC) foresees the construction and installation of important new equipment to increase the performance of the LHC machine. The Hollow Electron Lens (HEL) is a promising system to control the beam halo. It improves the beam collimation system of the HL-LHC and mitigates possible equipment damage in case of failure scenarios from halo losses. The halo can store up to 30 MJ energy. The specifications for this new device are quite demanding. The source, an electron gun with an annular shaped cathode, has to deliver a current up to 5 A. This is five times higher than the current in the existing electron lenses in Fermi and Brookhaven national laboratories. This note describes the programme carried out to design and test high-perveance guns equipped with two types of high-performance scandate cathodes. The size of the final gun is now considerably smaller than the one of the first prototype, allowing a reduction of diameter and cost of the superconducting magnet system used to steer the electron beam. The tests carried out at FNAL, BVERI and BJUT demonstrated that the developed cathodes fulfil the specifications and can supply a 5 A fully Space Charge Limited (SCL) current.
43 PARTICLE ACCELERATORS↗
Development program on a cold cathode electron gun
A prototype electron gun with a field emitter cathode capable of producing 95 mA in a 1/4 mm diameter beam at 12 kV was produced. Achievement of this goal required supporting studies in cathode fabrication, cathode performance, gun design, cathode mounting and gun fabrication. A series of empirical investigations advanced fabrication technology: More stable emitters were produced and multiple cone failure caused by chain reaction discharges were reduced. The cathode is capable of producing well over 95 mA, but a substantial collector development effort was required to demonstrate emission levels in the 100 mA region. Space charge problems made these levels difficult to achieve. Recommendations are made for future process and materials investigation. Electron gun designs were modeled and tested. A pair of two-electrode gun structures were fabricated and tested; one gun was delivered to NASA. Cathodes were pretested up to 100 mA at SRI and delivered to NASA for test in the gun structure.
Spindt, C. A.↗
The development of a multi-cathode electron gun
A multicathode electron gun, capable of automatically interchanging cathode structures of a microwave electron tube upon command was developed. This technique extends the life of a microwave electron tube into the range of fifty to one hundred years. The concept consists of mounting a number of cathode structures on a rotating platform. Rotation of the platform moves the different cathodes into operating position. The component tests, construction and operation of the gun are described.
Roberts, L. A.↗
Progress on the Electron Gun Design for a McMillan Electron Lens in the Fermilab Integrable Optics Test Accelerator (IOTA)
This paper covers the progress made so far in designing the first McMillan electron lens for the Fermilab IOTA ring. The novel design allows for an increase in tune spread without limiting the dynamic aperture due to its integrability. Shown are simulations for an electron gun design to generate the specific required current density distribution for the nonlinear integrable system in IOTA.
43 PARTICLE ACCELERATORS↗
Pulsed Electron Gun
Magnetically-collimated electron gun generates electron pulses with peak instantaneous currents of approximately microA with pulse widths of approximately 0.35 ns.
Srivastava, Santosh K.↗
Radial radio frequency (RF) electron guns
Radial radio frequency (RF) electron guns and radial RF electron gun systems are provided that are capable of generating an electron beam that can propagate either radially inward, towards the axis of a cylinder, or radially outward from the axis. A beam source capable of generating a radially inwardly propagating electron beam, while perhaps not particularly useful as a source for a higher-energy accelerator, offers potential advantages for materials processing, as the geometry allows irradiation from all sides of an enclosed material flow with a single structure. Other potential applications include, but are not limited to, atmospheric plasma generation, radiation damage testing, and possibly, novel electron lens-type devices for hadron accelerators.
Lewellen, John↗
Application of a radial radio-frequency electron gun to waste treatment
Electron-beam irradiation has been shown to be a clean, efficient, and effective technique for treating a variety of contaminants in a variety of media. In particular, the ionizing radiation produced by an electron beam can effectively decontaminate wastewater and aid in removing harmful chemicals from industrial flue gas. In this paper, we investigate a novel technique for waste treatment using an electron-beam system in which an (approximately) annular beam converges radially into the treatment volume. We provide preliminary system-level analysis of the design of a radial electron gun, and we discuss hypothetical system constructs in which a radial electron gun is used for treatment of flue gas and wastewater. We derive dose uniformity, throughput rates, and other important treatment parameters for each application. Our results suggest that a lower-energy system with a large-radius cylindrical treatment volume is preferable for flue gas treatment, whereas a higher-energy system with an annular treatment volume is better-suited for wastewater treatment.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Performance of a Carbon Nanotube Field Emission Electron Gun
A cold cathode field emission electron gun (e-gun) based on a patterned carbon nanotube (CNT) film has been fabricated for use in a miniaturized reflectron time-of-flight mass spectrometer (RTOF MS). Performance of the CNT e-gun has been evaluated. A traditional thermionic electron gun has also been fabricated and evaluated in parallel and its performance is used as a benchmark in the evaluation of our CNT e-gun. Implications for future improvements and integration into the RTOF MS are discussed.
Getty, Stephanie A.↗
An electrostatically and a magnetically confined electron gun lens system
Focal properties, electron trajectory calculations, and geometries are given for two electron 'gun' lens systems that have a variety of applications in, for example, electron-neutral and electron-ion scattering experiments. One nine-lens system utilizes only electrostatic confinement and is capable of focusing electrons onto a fixed target with extremely small divergence angles, over a range of final energies 1-790 eV. The second gun lens system is a simpler three-lens system suitable for use in a uniform, solenoidal magnetic field. While the focusing properties of such a magnetically confined lens systenm are simpler to deal with, the system does illustrate features of electron extraction and Brillouin flow that have not been suitably emphasized in the literature.
Bernius, Mark T.↗
A fast electron gun for study of atomic decays.
A fast electron gun with subnanosecond rise and decay times and 100 mA peak beam current has been developed for delayed coincidence studies of atomic decays. The gun is fabricated from an inexpensive tetrode nuvistor, only slightly modified. The electron gun system has been successfully used in a delayed concidence study of fast decays of ionized helium.
Sutton, J. F.↗
ELECTRON GUN FOR EVAPORATION OF OXIDE FILM
Electron guns for evaporation of refractory oxide film
OXIDE FILM↗