As Hall and ion thrusters are scaled to power levels below 300 W to operate on smalland micro-satellites, hollow cathodes must be designed to accommodate the new operating regimes with efficient use of power and propellant. The conclusions of previous cathode scaling efforts by other authors are reviewed, and the importance of heat transfer and orifice processes are emphasized. Performance data...

Energy distributions of N atoms in a hollow-cathode planar sputtering magnetron were obtained by use of optical emission spectroscopy. A characteristic line, N I 8216.3 Å, well-separated from molecular nitrogen emission bands, was identified. Jansson's nonlinear spectral deconvolution method, refined by minimization of χw , was used to obtain the optimal deconvolved spectra. These showed nitrog...

Energy distributions of nitrogen atoms (N) in a hollow-cathode planar sputtering magnetron were obtained by use of optical emission spectroscopy. A characteristic line, N I 8216.3 A, well separated from molecular nitrogen emission bands, was identified. Jansson's nonlinear spectral deconvolution method, refined by minimization of chi(2)(w), was used to obtain the optimal deconvolved spectra. Th...

A ferroelectric cathode is employed for the first time as the electron-beam source in a microwave amplifier tube. A PLZT 12/65/35 ferroelectric ceramic with a high dielectric constant ( 4000) is used in a form of a hollow cathode. The tube is operated in poor vacuum conditions (2 10 Torr) at room temperature, in a mechanism of a cyclotron-resonance maser amplifier. The device operates near the ...

In this paper, a review on microplasma discharges is conducted. The different types and configurations used in microplasmas such as the Cathode Boundary Layer (CBL), Dielectric Barrier Discharge (DBD), Capillary Plasma Electrode Discharge (CPED), Inverted Square Pyramid (ISP), Square Cross Sectional Cavities (SCSC), Radio Frequency Inductively Coupled Discharge (RFIC), Radio Frequency Capacitiv...

In the last decade, white-light illuminated Fabry-P\'erot interferometers wave been established as a widely used, relatively simple, reliable, and cost-effective way to precisely calibrate high-resolution echelle spectrographs. However, Terrien et al. (2021) recently reported chromatic drift of interferometer installed at Habitable-zone Planet Finder spectrograph. particular, they found that va...