The rigid stem chambers are designed as reference chambers for absolute dosimetry to be used in radiation therapy or by secondary standard dosimetry laboratories (SSDL). The chambers have been type tested by PTB-Braunschweig, the German National Laboratory. They have very small variations of response with radiation quality from low X-ray energies up to high-energy photon and electron radiation.

The nominal useful energy range is from 30 keV to 50 MeV. Both chambers are shaped cylindrically (thimble chambers). The wall material is graphite with a protective acrylic cover. The electrodes are made of graphite-coated aluminum. The guard rings border the measuring volume. Both chambers are constructed with a long stem of approx. 25 cm length for easy mounting in the radiation beam. An acrylic build-up cap for in-air measurement in Co-60 beams is included with each chamber, as well as a calibration certificate for calibration in absorbed dose to water or in air kerma. Air density correction is required for each measurement. A radioactive check device is available as an option. Features:

Thimble chambers for measuring high-energy photon and electron radiation in air and in phantom material

Suitable as reference chambers for use in solid phantoms

Vented sensitive volumes of 0.3 cm³ and 1 cm³

Very flat energy response within a wide range