BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-4826 DTSTART:20180421T170000Z DURATION:PT1H0M0S DTSTAMP:20260419T002529Z LAST-MODIFIED:20180416T191450Z LOCATION:2241 Chamberlin Hall SUMMARY:Gas Discharge Lamps – A Requiem\, JIMFEST 2018\, Graeme List er\, Lighting Consultant DESCRIPTION:Almost a century has passed since the introduction into th e market of gas discharge lamps for general lighting in the form of fl uorescent lamps\, made possible by the discovery of phosphors able to convert ultra-violet (UV) light to visible light in 1924. The journey from the first fluorescent lamps to\, efficient lamps producing high q uality light was an exciting one for researchers\, and much of the bas ic theory of gas discharge physics was developed by scientists during the early stages of gas discharge development. The trend for steady im provement continued through the end of last century\, but the discover y of efficient blue light emitting Light Emitting Diodes (LEDs) in the 1990s provided a path for lamp efficacies undreamed of and unattainab le by gas discharge sources. These “legacy” lamps will remain with us for many years\, perhaps decades to come\, but the overriding tren d in the market is towards introduction of LEDs for most general light ing applications\, due to the huge energy savings that will accompany them. There are certainly niche markets where LEDs have difficulty com peting\, but the general trend appears irreversible.
\nThis talk w ill take an affectionate and nostalgic backward look at the gas discha rge research for lighting to which I have devoted much of my career. M ost of the successes I have had would not have been possible without t he inspiration\, insight and friendship of Jim Lawler. The number of p apers we have published together bears testimony to this. The talk wil l describe a journey along the paths we trod to understand how gases p roduce light\, the fundamental principles involved\, the experiment pe rformed and the means of interpreting the results. Topics include stud ies of the negative glow\, the positive column\, and an extended look at “electrodeless“ fluorescent lamps and the efforts made to under stand their performance. More recent efforts to produce electrodeless metal halides will be discussed\, and finally a view on applications o f discharge lamps in the expanding market of lighting for plant growth . URL:https://www.physics.wisc.edu/events/?id=4826 END:VEVENT END:VCALENDAR