Designed for absolute and relative electron beam dosimetry
The parallel plate ionization chamber PPC40 is designed for absolute and relative electron beam dosimetry above 2 MeV in the measuring quantity absorbed dose to water. It can be used for proton beam absolute and relative dosimetry and for photon beam depth-dose measurements as well. The PPC40 is entirely made from PMMA; with graphitized electrodes. It is constructed with a circular sensitive volume of planar geometry covered by a rigid 1 mm thick entrance window. As an associated measuring instrument for precise absolute dose determinations, in reference dosimetry, compliance testing or installation and set-up of treatment machines or other equipment, it is recommended to use the reference-class therapy dosimeter Dose1. The PPC40 is waterproof and its cable is covered by a watertight silicon sleeve that allows for air ventilation.
Detector Brochure
Technical specs
Outer dimensions
- Chamber outer diameter: 44.0 mm
- Chamber body height: 10.0 mm
- Stem diameter: 10.0 mm
- Stem length: 50.0 mm
Inner dimensions
- Sensitive volume (nominal): 0.40 cm3
- Cylinder height: 2.0 mm
- Entrance window (polarizing electrode) diameter: 20.0 mm
- Entrance window thickness: 1.0 mm
- Diameter of collecting electrode: 16.0 mm
- Guard ring diameter: 17.8 mm
- Guard ring width: 3.4 mm
Operational characteristics
- Polarizing voltage: ±300 V (max. ±500 V)
- Typical leakage current: 5 fA
- Recommended pre-irradiation: 5 Gy
- Typical sensitivity: 11 nC/Gy
- Guard potential: ±300 V (max. ±500 V)
- Temperature range: 15 to 35 °C
- Relative humidity range: 20 % to 80 %