Thermally excited plasma modes are observed in trapped, near-thermal-equilibrium pure electron plasmas over a temperature range of 0.05,kT,5 eV. The modes are excited and damped by thermal fluctuations in both the plasma and the receiver electronics. The thermal emission spectra together with a plasma-antenna coupling coefficient calibration uniquely determine the plasma ~and load! temperature....

The appearance of resonant-particle effects in the linear dynamics of electron waves in a plasma whose electrons are trapped in a potential trough is discussed and conditions for the characteristic times involved are derived. For the special case of a parabolic potential trough it is shown that, within a limited time interval, a strong resonant effect may occur, due to the interaction of a wave...

Doppler reflectometry is considered in slab plasma model in the frameworks of analytical theory. The diagnostics locality is analyzed for both regimes: linear and nonlinear in turbulence amplitude. The toroidal antenna focusing of probing beam to the cutoff is proposed and discussed as a method to increase diagnostics spatial resolution. It is shown that even in the case of nonlinear regime of ...

This article describes an rf ion source with a back-streaming electron dump. A quartz tube, brazed to a metal plug at one end, is fused in the center of a flat quartz plate. rf power (at 13.6 MHz) is coupled to generate hydrogen plasma using a planar external antenna bonded to the window. Bonding the water-cooled rf antenna to the quartz window significantly lowers its temperature. The water-co...

Degradation of reliability caused by plasma induced damage (PID) has become a significant concern with miniaturizing a device size. In this paper, we measure frequencies of ring oscillators with an antenna structure on a single stage. In bulk, PID is relieved by connecting an antenna to a drain because electric charge flow to a substrate. The difference of initial frequencies is 0.79 % between ...

In the initial phases of the Levitated Dipole Experiment (LDX), multiple frequency ECRH (with frequencies between 2.45 and 28 GHz) will be used to produce a population of energetic electrons at high-β. Use of multiple frequency ECRH in mirror experiments have shown a reduction in plasma turbulence and increased heating efficiency. The pressure profile will be controlled by adjusting the relativ...

To study DEMO divertors, some linear devices have attempted to create DEMO-grade high-density steady-state divertor simulation plasma in a stronger magnetic field. Helicon sources using flat-type antenna, which are one of the methods radio frequency (RF) generation field, expected achieve this. In this study, we developed new RF source with two-turn flat-loop antenna having maximum output power...

The Alcator C-Mod experiment will study high power ICRF heating of elongated, diverted plasmas at high density in a compact, high field tokamak. ICRF heating will be carried out in the minority heating regime by fast wave excitation in a deuterium plasma with a 'He or H minority. Because of compact size of the tokamak, high loading will be required to couple the power at acceptable voltages and...

Damage free etching is required for the gate etching process in GaAs IC fabrication. While inductively coupled plasma (ICP) is thought to be the low damage etching technique, the degradation of DC characteristics was observed in our GaAs MESFETs. Threshold voltage shifts and Schottky barrier height is decreased. It was confirmed that the control of the antenna power (i.e. applied power to the u...