We present measurements of H and He emission absorption lines produced in RRab fundamental mode pulsators during primary light rise. The define universal progressions rise decay metal-poor stars. Such a progression cannot be constructed for metal-rich (those with [Fe/H]> -0.8) because weak I is detected only two the six our survey. Great variety exists phase variations blue- red-shifted compone...

We have studied ionization of alkali-metal Rydberg atoms by blackbody radiation (BBR). The results of theoretical calculations of ionization rates of Li, Na, K, Rb and Cs Rydberg atoms are presented. The calculations have been performed for nS, nP and nD states for principal quantum numbers n=8-65 at ambient temperatures of 77, 300 and 600 K. The calculations take into account the contributions...

We study the field-ionization threshold behavior when a Rydberg atom is ionized by a short single-cycle pulse field. Both hydrogen and sodium atoms are considered. The required threshold field amplitude is found to scale inversely with the binding energy when the pulse duration becomes shorter than the classical Rydberg period, and, thus, more weakly bound electrons require larger fields for io...

Strong few-cycle lasers enable sequential ionization of more than one electron per optical half-cycle. Understanding these correlated electron ionization events is crucial in developing a model of ionization dynamics in few-cycle laser fields and describing the foundations of laser plasma generation [1]. We have developed an experimental setup capable of characterizing correlated ionization eve...

Electrochemical or photo-electrochemical reactions in both electrospray ionization and laser desorption ionization are discussed stressing the role of the electrode reaction in influencing the ionization process. In particular, upon application of a high voltage during electrospray ionization, the emitter includes a working electrode, where redox reactions are observed, such as electro-generati...

Numerically determined ionization rates for the field ionization of atomic hydrogen in strong and short laser pulses are presented. The laser pulse intensity reaches the so-called “barrier suppression ionization” regime where field ionization occurs within a few half laser cycles. Comparison of our numerical results with analytical theories frequently used shows poor agreement. An empirical for...

A multiple ionization mass spectrometry strategy is presented based on the analysis of human serum extracts. Chromatographic separation was interfaced inline with the atmospheric pressure ionization techniques electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) in both positive (+) and negative (-) ionization modes. Furthermore, surface-based matrix-assisted laser ...

Helium and other atoms can, in principle, become doubly ionized when exposed to an intense laser pulse through two different channels: a direct process whereby both electrons are ejected simultaneously from the atom and a sequential process whereby the second charge state is created only after the first charge state. Crance and Aymar [1] calculated for He that if the number of photons required ...