Always perpendicular to the beam:
Truly angle-independent measurements

Fig. 1: Detector always perpendicular to the beam
The OCTAVIUS 4D phantom offers perfect isotropic measurement geometry. It rotates the detector synchronously with the gantry, always perpendicular to the beam, thus eliminating any angular dependence of the detector response (Fig. 1).

Fig. 2: Truly angle-independent measurements
OCTAVIUS 4D (right) compared to other dosimetry systems (left, center) where inclined beam vectors result in a varying angular response of the diodes.