|MadSci Network: Physics|
Good morning Chun Ming Wong!
I would be more than happy to answer your question about fluorescent lamp flicker/failure, but the theory of operation of them is quite involved, and the reasons for their failure are many and varied. The short explanation is this: A fluorescent tube emits light by the ultra-violet photons from a mercury (Hg) arc created within the tube, striking a phosphor coating on the inside surface of the tube. This coating then re- emits the energy in the visible electromagnetic spectrum, which we perceive as light. Anything that interrupts the arc (plasma) will be noticeable as decreased light output, flickering, or total failure. Temperature, voltage, current, contamination of the gases within the tube are all factors that must be considered.
Rather than re-inventing the wheel, so to speak, I would direct you to the following website for an excellent explanation of fluorescent lighting theory, construction, and potential problems and their causes: korry backlighting
Karl Kolbus - the not-so-mad scientist!
[note added by MadSci Admin: The "korry backlighting" URL is the 3rd page in a series of 9 pages. Be sure to look at all 9 pages!!
Also, most fluorescent lamps fail when one (or both) of the filaments ages and fails to provide sufficient current through the lamp. However, there are many modes of failure, not the least of which is the failure of the active resistor in the lamp fixture (the "ballast").]
Try the links in the MadSci Library for more information on Physics.