Time-dependent registration of ionization current for spectroscopy of rydberg atoms

Spectroscopy of atoms in Rydberg states was an object of extensive investigation (see for example [1-5] and references therein). Usually necessary population of Rydberg states is achieved by means of multi-stage pulse laser pumping. That is why useful signal of ionization current from Single Channel Electron Multiplier (CEM or channeltron) is also pulse signal. Essential temporal instability of this signal is one of the main problems during its registration. More over in order to investigate Rydberg spectra of elements with high value of ionization potential (Al, Cu, Au etc.) it is necessary to apply high-temperature source of atoms (up to 2000 3000K). That is why there appears effect of redistribution of population by means of black body radiation. This effect makes additional difficulties to study ionization spectra. In order to overcome these obstacles we propose to apply time-dependent registration of ionization current from CEM. First of all such approach will allow us to store individual time-dependent realizations and to provide averaging of these realizations numerically excluding temporal instability. In addition after improvement of the receiving system it will be possible to detect ionization spectra resolving Rydberg states populated by means of black body radiation.