The xenon tube is used in cameras with an electronic flash, LASERs and in strobes. The tube is made from glass or quartz, has an electrode in each end and contains high pressure xenon gas. It also has a third connector for triggering.

To use the tube a capacitor connected to the electrodes is charged to between 200V and 400V. Since xenon is normaly nonconductive, it needs some help to flash. This is done by sending a 3-6kV pulse on the trigger electrode (Some flashtubes doesn't have a trigger connector, but here the trigger voltage is connected to the reflector behind the tube) The pulse 'injects' a flow of electrons in to the tube. This causes an avalanche effect where the electrons hit the xenon atoms, that emits more electrons and so on. This ionizes the gas and makes it connductive, and the capacitor is discharged through the tube. The accelerated electrons that fly trough the tube knocks away atoms from the electrode when it hits, and after 5000-7000 discharges the tube must be replaced(Strobe tubes work at lower effects, and can survive several million flashes).

Log in or register to write something here or to contact authors.