Preferred Label : Penning gas mixture;
IUPAC definition : A Penning gas mixture consists of a rare gas containing impurity atoms possibly at
very low concentrations. The impurity atoms have an ionization potential V ion which
is lower than or equal to the metastable potential (V meta) of the parent noble gas.
The Penning effect in a Penning gas mixture is the ionization by charge transfer (charge
exchange) during collision between a metastable atom and a neutral atom which decreases
the average energy to form an ion pair, e.g. In a glow discharge, this results in
an increase of the the ionization coefficient (Townsend first coefficient), a decrease
in breakdown potential and a lowering of the cathode fall potential. The magnetic
Penning effect describes the increase of the ionization probability of gas in a low
pressure electrical discharge resulting from the helical (spiral) movement of electrons
in a magnetic field placed normal to the anode-cathode electrical field.;
Origin ID : P04476;
See also
A Penning gas mixture consists of a rare gas containing impurity atoms possibly at
very low concentrations. The impurity atoms have an ionization potential V ion which
is lower than or equal to the metastable potential (V meta) of the parent noble gas.
The Penning effect in a Penning gas mixture is the ionization by charge transfer (charge
exchange) during collision between a metastable atom and a neutral atom which decreases
the average energy to form an ion pair, e.g. In a glow discharge, this results in
an increase of the the ionization coefficient (Townsend first coefficient), a decrease
in breakdown potential and a lowering of the cathode fall potential. The magnetic
Penning effect describes the increase of the ionization probability of gas in a low
pressure electrical discharge resulting from the helical (spiral) movement of electrons
in a magnetic field placed normal to the anode-cathode electrical field.
