Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"Electron source"”.
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A high average-current electron source for the Jefferson Laboratory free electron laser
… from the Jefferson Laboratory infra-red free electron laser is primarily limited by the performance of the electron injector. Free electron laser power is directly proportional to the electron beam current and at present the electron injector is limited to 10mA average current. To date the …
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Double-gated isolated vertically aligned carbon nanofiber field emission and field ionization arrays
Electron impact ionization (ElI) is used extensively in mass spectrometry for gas-phase analytes. Due to the significant amount of fragmentation generated by ElI, the spectrum is usually very noisy. In addition, the thermionic emission electron source used in ElI has a slow response time and …
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The penning trap electron gun for the KATRIN experiment
… 2010. The experiment will measure the energy of electrons recoiling from the three body beta decay of Tritium (Hydrogen with two neutrons) in order to obtain the mass of the neutrino. The experiment will be sensitive down to 0.2ev/c2. My thesis focuses on the one of the calibration sources for …
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Karlsruhe Tritium Experiment: Detector System Commissioning and In-Situ PIN-Diode Array Dead-Layer Measurement
… of the KATRIN experiment is determined by the source strength and the main spectrometer resolution, but a confluence of focal plane detector parameters contribute to the uncertainty in the measured neutrino mass including the detector backgrounds and the detector electron response function. The …
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Dose analysis of the Model 112A Pulserad Pulsed X-Ray Generator by ITS/CYLTRAN.
… photon energy spectrum is independent of the electron source beam parameters such as beam radius and angular distribution. A previously unexplained measured dip in the radiation dose at the beam center line can be explained with an angular divergence of the electron beam from the cathode. The …
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Experimental study of rare-gases excimer VUV system and H2 Lyman-bands calibration
An electron impact rare gas excimer vacuum ultra-violet experimental system is custom-designed and tested using an argon and H2 mixture. An electron flooding system, i.e. filament, is used as the hot electron source. A SiNx membrane is applied as the entrance foil separating the high vacuum chamber …
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Development of optical field emitter arrays
Optical field emitters are electron emission sources actuated by incident light. Optically actuated field emitters may produce ultrafast pulses of electrons when excited by ultrafast optical pulses, thus making them of interest for specific applications such as ultrafast electron microscopy, …
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Swept Neutral Pressure Instrument (SNeuPI): Investigating Gravity Waves In The Ionosphere
… is achieved by use of micro-tip emitters as an electron source and micro channel plates(MCPs) as ion collectors. Ionization of the neutral gas produces a current at the output of the MCPs to quantify the pressure of the ionosphere. Traditionally, such measurements are made on larger satellites …
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Spin-polarized low energy electron diffraction studies of Cu¿Au(001)
Combined measurements in low-energy electron diffraction of both intensity and diffracted electron spin-polarization are obtained for Cu,Au(1). Here the use of polarized LEED represents a refinement over standard LEED techniques because additional and complementary data is obtained. In addition, …
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Double-gated field emission arrays
… parallel, individually addressed and focused electron sources for applications such as flat panel displays, mass storage and multi-beam electron beam lithography. This project fabricates and characterizes double-gated field emission devices with high aspect ratio. One of the gates extracts the …
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Silicon field emission pressure sensor
… as device medium and field emission cathode as electron source, a renewed interest in vacuum microelectronics utilizing advanced IC technology is emerging. This thesis demonstrates an application of field emission emitters in two novel pressure sensors. One is based on a diode structure with one …
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Spin holography
In electron emission holography, the sources are electron emitting atoms. The primary (unscattered) electron wave interferes with the waves scattered elastically by nearby atoms resulting in a holographic fringe pattern in the angular distribution of the emitted electrons. In cases that the …
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Miniaturized electron-impact-ionization pumps using double-gated isolated vertically aligned carbon nanotube arrays
… can be readily integrated with other MEMS and electronic components at the chip-scale level. Miniaturized ion pumps exhibit favorable scaling down because they are surface-limited and miniaturization increases the ratio between the active surface and the chamber volume, resulting in enhanced …
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Magnetostatic Modelling and Measurement for Particle Dynamics of a Magnetic Energy Filter
… filter designed to selectively filter low-energy electrons from beams produced by electron sources. Two electron source configurations—based on a direct current (DC) 0.5 MeV electron gun and a 3.5 MeV radio frequency (RF) electron gun available at the Canadian Light Source (CLS) test …
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Low-Energy Electron-Photon Interactions in a Scanning Electron Microscope
The interaction of free-electrons with matter and light is among the most fundamental of processes in nature. From the use of free-electrons for atomic imaging, to their use in the generation of high-intensity, tunable light in synchrotrons, the physics of unconfined electrons has wide application. …
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Fast-ion spectrometry of ICF implosions and laser-foil experiments at the omega and MTW laser facilities
… and intensity of the driver, generate hot electrons with temperatures ranging from tens to thousands of kilo-electron-volts. These electrons, which accelerate the ions measured in this work, can be either detrimental or essential to implosion performance depending on the ICF scheme …
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Investigation of the feasibility of sensing transient velocity by means of gaseous ionization
… of voltage, electrode separation and primary electron source strength. A curie of tritium placed on the central portion of either electrode produced a constant initial emission current and a high sensitivity. Sensitivity could be increased by using a stronger current source, higher voltage and …
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Experimental studies of the dynamics of neutral electron-positron beams
… interaction between relativistic quasi-neutral electron-positron beams and an ambient electron-ion plasma. In both investigations, the Astra-Gemini laser system was used to produce laser-wakefield accelerated electron beams, that subsequently seeded a quantum electromagnetic cascade in a high-Z …
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generation and transport of high-current relativistic electron beams in high intensity laser-solid interactions
… ultra-high intensity laser-driven relativistic electron beams in overdense plasma is investigated experimentally and numerically. The fast electron beam is experimentally diagnosed by means of a 2D Cu Kα imager and the TNSA-generated proton beam. Analytical models together with a 3D hybrid-PIC …
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Carrier transport properties measurements in wide bandgap materials
… two were optical beam induced current (OBIC) and electron beam induced current (EBIC) time of flight transient measurements. These techniques consist of measuring the current response to the drift and diffusion of generated electron-hole pair carriers created by a short-duration pulse of …
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