Conveners
2.5 Codes and Modeling and 2.8 THz Sources, Radiation, and Applications
- Ian Rittersdorf
Global models have become a popular tool for estimating volume-averaged plasma parameters such as number densities of plasma components, or electron temperature in partially-ionized plasmas of practical interest (with possibly thousands of chemical species and hundreds of thousands of chemical reaction paths in the discharge). Due to the usage of a volume-averaged approximation, global models...
The development of a low-impedance magnetically insulated line oscillator (MILO) driven by a compact Marx generator developed by Texas Tech University is discussed. The goals of the project aim to develop a MILO operating within the S-Band that can provide an RF peak output power of greater than 1 GW with greater than 10% efficiency. The device design followed a set of base design equations...
The Miram curve for a specific cathode surface describes the normalized current density as a function of cathode temperature. Understanding and predicting this curve is key to understand the performance vs. lifetime of many electrons gun sources [1]. As the cathode lifetime decreases rapidly with increased operating temperature, in many practical devices, the electron gun is operated just...
The surfaces of electron sources exhibit non-planar features (intentional ordered arrays here but the methods apply also random surface roughness), the dimensions of which are typically microscale and therefore much smaller than the active emission area [1, 2, 3]: because emission area is already small by comparison to device dimensions, such differences in magnitude are a challenge to beam...
This work presents a laser-driven semiconductor switch (LDSS) employing silicon (Si) and gallium arsenide (GaAs) wafers that has been used to produce nanosecond-scale pulses from a 3 μs, 110 GHz gyrotron at the megawatt power level. Photoconductivity was induced in the wafers using a 532 nm Nd:YAG laser, which produces 6 ns, 230 mJ pulses. Irradiation of a single Si wafer by the laser produced...
High peak power tunable THz sources are enabling tools for medicine and materials science, non-destructive evaluation, space exploration. There is a special class of military and defense applications that includes THz communication, atmosphere monitoring, stand-off weapon and contraband detection, crowd screening. All applications require highest possible power to increase the detection...
Probing structural dynamics at atomic spatial and ultrashort temporal scales reveals unprecedented details of nature’s fundamental behavior, allowing for better understanding of intricate energy-matter interaction occurring at such scales. Ultrafast electron diffraction (UED), is the ideal choice to capture information from atomic-scale initiated by a pump laser and probed by MeV electrons....
Increasing of electron beam current density is important problem in development of a THz generator. Howeever a conventional thermionic cathode have limited current density. Experiments with magnetron gun with transaction on plasma mode are described. The gun has a metall cathode with a diameter of 6 mm and a length nearly 70 mm. The cathode was coaxially mounted inside a stainless tube with a...
