Townsend discharge

Avalanche effect in gas subject to ionising radiation between two plate electrodes. The original ionisation event liberates one electron, and each subsequent collision liberates a further electron, so two electrons emerge from each collision to sustain the avalanche.

Voltage-current characteristics of electrical discharge in neon at 1 torr, with two planar electrodes separated by 50 cm.
A: random pulses by cosmic radiation
B: saturation current
C: avalanche Townsend discharge
D: self-sustained Townsend discharge
E: unstable region: corona discharge
F: sub-normal glow discharge
G: normal glow discharge
H: abnormal glow discharge
I: unstable region: glow-arc transition
J: electric arc
K: electric arc
A-D region: dark discharge; ionisation occurs, current below 10 microamps.
F-H region: glow discharge; the plasma emits a faint glow.
I-K region: arc discharge; larges amounts of radiation produced.

Neon lamp/cold-cathode gas diode relaxation oscillator

Plot of variation of ionisation current against applied voltage for a co-axial wire cylinder gaseous radiation detector.

The Townsend discharge or Townsend avalanche is a gas ionisation process where free electrons are accelerated by an electric field, collide with gas molecules, and consequently free additional electrons. Those electrons are in turn accelerated and free additional electrons. The result is an avalanche multiplication that permits electrical conduction through the gas. The discharge requires a source of free electrons and a significant electric field; without both, the phenomenon does not occur.

单词	Townsend discharge
释义	Townsend discharge 英语百科 Townsend discharge The Townsend discharge or Townsend avalanche is a gas ionisation process where free electrons are accelerated by an electric field, collide with gas molecules, and consequently free additional electrons. Those electrons are in turn accelerated and free additional electrons. The result is an avalanche multiplication that permits electrical conduction through the gas. The discharge requires a source of free electrons and a significant electric field; without both, the phenomenon does not occur.
随便看	starch iodine reaction的意思 starch iodine test的意思 Starchitect的意思 starchitects的意思 Starchitecture的意思 starchitectures的意思 starch jelly candy的意思 starch kernel的意思 starch laurate的意思 starch layer的意思 starch leaf的意思 starchless的意思 starchlike的意思 starchliker的意思 starchlikest的意思 starch lump的意思 starchly的意思 starch machine的意思 Starch maize的意思 starch mark的意思 starch mash的意思 Starch measurement的意思 starch microsphere的意思 starch milk的意思 starch mobility的意思