Patent ID: 6515418
Filing Date: 2003-02-04
Classification: H01J

Abstract:
High pressure sodium vapour lamp having a fill consisting of sodium, mercury and xenon in an arc tube with a sodium weight portion within the sodium-mercury-amalgam of approx. 12% to approx. 20%, having a xenon filling pressure in the cold state between approx. 180 Torr and approx. 350 Torr, having a D-line reversal width (distance of the tops of both wings of the sodium-D-line of the radiation spectrum) of between approx. 100 Ã¥ and approx. 200 Ã¥, and having between approx. 14% and approx. 18% radiation portion in the red wave lengths range 635 nm to 750 nm and having between approx. 7% and approx. 10% radiation portion in the blue wave lengths range 380 nm to 500 nm, in each case of the radiation power in the wave length range 380 nm to 780 nm for promotion of plant growth.