Highly Charged Ion

A Highly Charged Ion ( highly charged ion ), abbreviated HCI, is an atom that has lost many electrons and therefore has a high positive electric charge.

The maximum achievable positive charge is the "bare " nucleus, ie the number of protons in the nucleus. For example, an iron atom ( chemical symbol Fe), whose nucleus contains 26 protons, 13 electrons emit at temperatures of about 1 million degrees in the solar corona and a 13 -fold positively charged () ion occur. In solar flares can occur even due to the much higher temperature also about ( ) ions.

Ion, to which a single electron is still attached, is called hydrogen- like manner, according to the element hydrogen, which has only one electron in the neutral state; analog is referred to as helium -like, like lithium, etc. ( according to the elements of helium, lithium, which have two or three electrons in the neutral state ), those who have two or three electrons. The number of bound electrons determines the basic structure of the emission spectrum of these ions, which can therefore be classified in the isoelectronic series. With increasing charge on the ion, although the emission lines of the spectrum are becoming increasingly high-energy, ie, short-wave, but the relative arrangement and the number of lines to remain within a range isoelectronic largely unchanged.

Highly charged ions allow due to their emission lines through telescopes and spectrographs the analysis (see also plasma diagnostics ) the chemical composition, temperature and density of extremely hot plasmas in astrophysics. Similar methods are used to study the magnetically confined plasmas in nuclear fusion research.

The study of highly charged ions in the laboratory is possible by means of heavy ion accelerators and the Electron Beam Ion Traps.