A systematic mass spectrometric survey has been performed to study ionic species that are formed in continuous supersonic planar plasma. he plasma is generated by electron impact ionization of gas that is expanded supersonically through a long and narrow slit. A quadrupole mass pectrometer is used to sample the adiabatically cooled plasma downstream for different precursor mixtures. The number ...

In this work, we present for the first time, a highly scalable general high voltage MOSFET model, which can be used for any high voltage MOSFET with extended drift region. This model includes physical effects like the quasi-saturation, impact-ionization and self-heating, and a new general model for drift resistance. The model is validated on the measured characteristics of two widely used high ...

Simulation results of InAlAs/InGaAs High Electron Mobility Transistors based on both GaAs and InP substrates are presented using the two-dimensional device simulator MINIMOS-NT. Three different HEMT technologies are evaluated by simulation and a single set of physical parameters is verified. The critical interaction of selfheating, impact ionization, SiN surface effects, and material compositio...

ATHENA’s first detection of cold antihydrogen atoms relied on their annihilation signatures in a sophisticated particle detector. We will review the features of the ATHENA detector and its applications in trap physics. The detector for a new experiment ALPHA will have considerable challenges due to increased material thickness in the trap apparatus as well as field non-uniformity. Our studies i...

Micromachined vacuum pumps are one of the key components in miniature systems for chemical and biological analysis. Miniature sensors and analyzers are normally operated at the pressure range lower than a few millitorr. We are developing a micromachined vacuum pump that is comprised of a mechanical rough pump integrated with micromachined ion-pumps. The rough pump generates a low vacuum of tens...

Electroluminescence is observed during porous etching of n-type GaP single crystals at strongly positive potential. The emission spectra, which include a supra-bandgap contribution, are markedly different from the spectra observed under optical excitation or minority carrier injection. The current density and electroluminescence intensity show a strong potential dependence and a similar hystere...

This paper presents measurements of the avalanche multiplication factor (M 1) in SiGe HBT’s using a new technique capable of separating the avalanche multiplication and Early effect contributions to the increase of collector current with collector-base bias, as well as allowing safe measurements at practical current densities. The impact of collector doping, current density, Ge profile, and ope...

D. Bernhardt,1 A. Becker,2 M. Grieser,2 M. Hahn,3 C. Krantz,2 M. Lestinsky,4 O. Novotný,3 R. Repnow,2 D. W. Savin,3 K. Spruck,1,2 A. Wolf,2 A. Müller,1 and S. Schippers1,* 1Institut für Atom und Molekülphysik, Justus-Liebig-Universität Giessen, Leihgesterner Weg 217, D-35392 Giessen, Germany 2Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany 3Columbia Astrophysi...

The efficiency of nonequilibrium electron trapping by capture centers in alkali halide crystals, quartz, and polymethyl-methacrylate exposed to an intense electron beam with a beam current density of about 20 A/cm 2 is studied. The trapped charge is estimated from the amount of irradiation-induced electrification of high-resistivity materials. It is shown that traps having captured thermalized ...

The calculation of total integral cross sections for electron-impact ionization of atoms and atomic ions has, in the last 8 years, greatly benefited from the development of several nonperturbative methods, which generally show very good agreement with each other and with experiment. For the electron-impact ionization of hydrogen, the convergent close-coupling @1#, the hyperspherical close-coupl...