PPC05 Plane Parallel Chamber

Description

The parallel plate ionization chamber PPC05 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 photon and proton absolute and relative dosimetry as well.

The construction materials are air equivalent conducting plastic Shonka C552 (housing, entry window and side walls) and highly insulating plastics PEEK and PPE. The collecting electrode material is graphitized PEEK. The chamber is constructed with a circular sensitive volume of planar geometry covered by a rigid 1 mm thick entry window. The small collecting volume with 0.6 mm plate spacing, 9.9 mm diameter and a 3.4-mm-wide guard ring enables excellent resolution in depth dose studies and requires a small perturbation correction. The chamber is waterproof and vented through a silicone sleeve


Technical specs

Outer dimensions

  • Chamber outer diameter: 30.0 mm
  • Chamber body height: 14.0 mm
  • Stem diameter: 8.5 mm
  • Stem length: 38.0 mm

Inner dimensions

  • Sensitive volume (nominal): 46.0 mm3
  • Cylinder height: 0.6 mm
  • Entry window (polarizing electrode) diameter: 20.0 mm
  • Entry window thickness: 1.0 mm (0.176 g/cm2)
  • Diameter of collecting electrode: 9.9 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: 1.7 nC/Gy
  • Guard potential: ±300 V (max. ±500 V)
  • Temperature range: +15 – +35 °C
  • Relative humidity range: 20 % – 80 %