101
Revision 00 EN - 01/2021
HP-MSM-HB
35,0(6
23.2.2
Determination of the beam position
The beam position is determined by means of the 1. moment method. This means the moment of inertia of
the power density distribution (E(x, y, z)) is determined.
(1.5)
As mentioned at the beginning of the chapter, there are two possibilities how to determine the beam radius
after the determination of the beam position.
23.2.3
Radius determination with the 2. moment method of the power density distribution
The calculation of the beam radius according to the 2. moment method of the power density distribution is
effected as shown in equation
(1.6)
.
(1.6)
Based on equation
(1.6)
the beam diameter is determined as follows:
(1.7)
This algorithm contains the product derived from the power density and the squared distance to the moment
of inertia. It is only reliable when the zero level is determined correctly. The fill factor, the ratio of the beam
diameter divided by the integration range/measuring window size is a further important quantity. It should
always have a value between 0.35 and 0.7.
