Published online by Cambridge University Press: 15 February 2011
Starting with basic physical radiation principles and with Beers law formulas for the radiation characteristics of arrays of pointlike radiation sources and tubular halogen lamps are analytically derived. Different arrangements of tubular halogen lamps are considered and compared with each other. Homogeneity criteria are worked out and it is demonstrated that the minimum homogeneity distance between a plane in which all filaments are arranged parallel to each other, and an object depends only on the distance between two neighbouring filaments and thus can be given by a simple number. Interesting aspects for RTP equipment manufacturers as well as for users are demonstrated by comparing different lamp arrangements with each other: In crossed lamp fields latticelike inhomogeneity knots arise in the object plane at points where the lamp filaments of the upper and the lower lamp plane cross. If the filaments are arranged parallel to each other in two filament planes, very homogeneous results are obtained when the filaments of the two planes interlace.