Generation of charged droplets by field ionization of liquid helium

Generation of charged droplets by field ionization of liquid helium

Positively charged helium droplets were produced by ionization of liquid helium in an electrostatic spraying experiment, in which fluid emerging from a thin glass capillary was ionized by applying a high voltage to a needle inside the capillary. At 2.2 K, fine droplets (<10 μm in diameter) were produced in pulsed sprays or showers with total currents as high as 0.4 μA at relatively low voltages...

Ionization-excitation of helium by fast charged particles.

Catching proteins in liquid helium droplets.

An experimental approach is presented that allows for the incorporation of large mass-to-charge ratio selected ions in liquid helium droplets. It is demonstrated that droplets can be efficiently doped with a mass-to-charge ratio selected amino acid as well as with the much bigger m ≈ 12,000 amu protein cytochrome C in selected charge states. The sizes of the ion-doped droplets are determined vi...

Femtosecond ionization of magnesium clusters grown in ultracold helium droplets

Magnesium clusters grown in helium droplets and ionized with femtosecond laser pulses have been studied by high resolution mass spectrometry. For moderate laser intensities the abundance spectra show characteristic features indicating electronic shell effects. Compared to clusters of s–electron metals additional shell closures appear resulting from an electron rearrangement. Irradiation with hi...

Coalescence of Charged Droplets in Agitated Liquid-Liquid Dispersions

Experimental studies have been performed to assess the effect of drop charge on turbulent drop coalescence. Although it is well known that surface charge can affect coalescence rates of Brownian particles in a quiescent medium, no studies have been found in the literature which explicitly examine charge effects on larger drops in turbulent media. Results demonstate that drop charge can substant...