Fluke Biomedical 30-471 - Manual (Page 12)

Nuclear Associates 30-471
Operators Manual
2-4
12-17 MV Diodes
As seen in the following figures, the results are good for angle variations in the plane perpendicular to the
direction of the cable. Again, there is a small (less than 1%) variation extending to ± 30-35 degrees off
center. Along the plane that includes the cable there is a 3% - 4% variation over the same angular range.
Gantry angle (degree with 180 being vertical)
Diode (type 472 [5–11 MV rated]) output vs. incident angle;
asymmetric setup in 6 MV photons
Diode out
p
ut (n
ormalized
to
180°)
Gantry angle (degree with 180 being vertical)
Diode (type 473 [12–17 MV rated]) output vs. incident angle;
symmetric setup in 6 MV photons
Diode out
p
ut (n
ormalized
to
180°)