It appears that the tactical chemical laser the US has been hoping to deploy to protect the Zionist Entity from rockets launched by Hezbollah guerrillas in southern Lebanon is, in the words of its developers, "not ready for action." http://www.newsday.com/ap/text/international/ap796.htm According to the defense department blurb on the system, called THEL (http://www.smdc.army.mil/FactSheets/THEL.html), the system employs deuterium fluoride as the lasing medium. Since deuterium is somewhat more expensive to produce than ordinary hydrogen, one wonders why the system has been designed to work with deuterium. Is it because the government does not want fuel for it to be easily produced, should the design fall into enemy hands. Or is there some engineering advantage to using deuterium? Does excited deuterium fluoride have some wonderful spectral line in exactly the right place, that pedestrian hydrogen fluoride does not? Any chemical or nuclear engineers here who could answer the question of why deuterium is more desirable? -- Eric Michael Cordian 0+ O:.T:.O:. Mathematical Munitions Division "Do What Thou Wilt Shall Be The Whole Of The Law"