Use of a particle beam glow discharge (PB-GD) source for mass spectrometric determinations of deoxy- and ribonucleosides and nucleotides is described. Use of this combination of sample introduction and ion source decouples the vaporization and ionization steps, leading to very simple spectral structure. The mass spectra of these compounds are EI-like in nature, with clearly identified molecular...

A fast gas flow through a negative glow plasma creates an afterglow region where supercooled electrons are separated from energetic beam electrons to produce a population inversion by collisional recombination. We report spatially-resolved electron temperature measurements of the afterglow plasma showing electron temperatures in the range of 750-1100 K under steady-state conditions. A 4 em long...

A novel power supply system that directly couples pulsed high voltage (HV) pulses and pulsed 13.56 MHz radio frequency (rf) has been developed for plasma processes. In this system, the sample holder is connected to both the rf generator and HV modulator. The coupling circuit in the hybrid system is composed of individual matching units, low pass filters, and voltage clamping units. This ensures...

A novel chemical ionization source for organic mass spectrometry is introduced. This new source uses a glow discharge in the flowing afterglow mode for the generation of excited species and ions. The direct-current gas discharge is operated in helium at atmospheric pressure; typical operating voltages and currents are around 500 V and 25 mA, respectively. The species generated by this atmospher...

RF glow-discharge plasmas provide mild energetic ion bombardment of exposed surfaces. The characteristics of a 10 MHz RF glow-discharge Ar plasma are studied by particle-in-cell simulation. The model simulates a spherical plasma device using a one-dimensional plasma model. The code is used to determine the breakdown voltage, Vrf , for a given pd , where p is the gas pressure and d is the plasma...