We present a characterization of molybdenum sources, ΓMo , core Mo density, nMo, and their dependencies on Alcator C-Mod operational regimes. This includes sources from the divertor, the inner wall and the ICRF antenna limiters. We also present information characterizing the penetration of these impurities into the core plasma under different conditions based on penetration factors, PF=nMo/ΓMo ...

The input impedance of a large circular loop antenna with arbitrary orientation in a cold magnetoplasma is calculated by using a transmission line theory. New impedance resonances for antennas of finite size in a magnetoplasma in the frequency region below and near the electron cyclotron frequency are indicated theoretically. The resonance peak of the impedance at the lower hybrid resonance fre...

An inductively coupled plasma source, designed for ion beam applications, is allowed to float up to several kilovolt positive. If one side of the radio frequency (rf) antenna is grounded and the dielectric source tube and the surrounding air are allowed to reach a threshold temperature corona breakdown at the rf antenna occurs. The experiments presented here show that a dc corona can be ignited...

Inductive current profile modification in MST has been successful in reducing fluctuations and transport but is transient and radially non-localized. Current profile control with rf waves offers steady and more precise control. Studies of lower hybrid wave and electron Bernstein wave injection are underway. The lower hybrid antenna has coupled 125 kW to the plasma. Hard x-ray emission with ener...

The RF ion source at Spallation Neutron Source has been upgraded to meet higher beam power requirement. One important subsystem for efficient operation of the ion source is the 2MHz RF impedance matching network. The real part of the antenna impedance is very small and is affected by plasma density for 2MHz operating frequency. Previous impedance matching network for the antenna has limited tun...

Fast Waves (FWs) at 60 MHz and 90 MHz are used in DIII-D for central electron heating and current drive. Coupling of FWs to high-performance discharges is limited by low antenna loading in these regimes. To extend the application of high-power FWs to such regimes, methods of increasing the antenna loading in these regimes are needed. A systematic study of loading enhancement techniques has been...

A 2.58THz detector based on plasma-wave theory proposed by Dyakonov and Shur was designed fabricated in 55nm standard CMOS process. Each consists of a filter patch antenna metal-oxide-semiconductor field-effect-transistor (MOSFET). We design to receive the terahertz signal, output is extracted phase-locked amplifier. The generates filtering function adding two pairs branches feeding lines. freq...

a newly designed printed slot antenna is presented that incorporates variable two band-notched functions for ultra-wideband (uwb) applications. the two band notches of this coplanar waveguide (cpw) fed antenna are achieved by an m-shaped slot (mss) embedded in the radiating element and a c-shaped strip(css) close to ground plane, therefore two very narrow rejected properties in the wireless loc...

A compact microstrip-fed antenna with dual notched bands is proposed. First, a simple basic configuration is presented for Ultra Wide Band (UWB) applications and then the dual band notched structure is extended from the UWB one. The basic structure of the UWB antenna consists of a simple square radiating patch and a ground plane with a wide square slot on back of the substrate. A semi-circle sh...

Antenna 3D pattern measurement can be a tedious and time consuming task even for antennas with manageable sizes inside anechoic chambers. Performing onsite measurements by scanning the whole 4π [sr] solid angle around the antenna under test (AUT) is more complicated. In this paper, with the aim of minimum duration of flight, a test scenario using unmanned aerial vehicles (UAV) is proposed. A pr...