Stereotactic Calibration Phantom
The CNMC Model SWP-1427 water-filled stereotactic calibration phantom offers an economical means of achieving the desired depth when calibrating a stereotactic beam with a N23342 plane-parallel ion chamber. The phantom consists of a 13cm diameter acrylic cylinder, 27cm high, bonded to a 14cm x 14cm, 5mm thick
water-equivalent plastic base. This configuration offers zero depth correction. The water level may be conveniently adjusted using the spigot mounted in the side of the cylinder.
In use, the N23342 ion chamber is placed into a phantom section that is custom machined to position the chamber sensitive volume at the exact beam central axis, with its window flush with the phantom top surface. The water-filled calibration phantom is then placed on top of the phantom section. Exact depth is achieved by adding water to the cylinder.
In the same manner, the SWP-1427 may be used on top of the STP-156 phantom that accommodates a small field semiconductor detector for achieving variable build-up.