Features
- Vented sensitive volume of 28 cm3
- Suitable as high precision reference chamber for radiation protection dosimetry
- Very flat energy response within a wide range
The spherical chamber TK-30 is designed as a reference chamber for absolute dosimetry to be used by secondary standard dosimetry laboratories (SSDL) and users with high quality requirements. It has very small variations of response with radiation quality from low X-ray energies up to high-energy photon radiation. The guard ring is designed up to the sensitive volume. The chamber is constructed with a long rigid stem of approx. 20 cm length for easy mounting in the radiation beam. Air density correction is required for each measurement.
Specifications
| Type of product | vented spherical ionization chamber |
|---|---|
| Application | radiation protection measurements |
| Measuring quantity | photon equivalent dose, exposure |
| Nominal sensitive volume | 27.9 cm3 |
| Design | not waterproof, vented |
| Reference point | chamber center |
| Direction of incidence | radial |
| Nominal response | 0.8 µC/Sv |
| Chamber voltage | 400 V nominal ± 1000 V maximal |
| Energy response | < ± 5 % (48 keV … 60Co) |
| Directional response in air | < ± 0.5 % for for rotation around the chamber axis and < ± 3 % for tilting of the axis up to ± 45° |
| Leakage current |
≤ ± 5 fA |
Materials and measures
| Wall of sensitive volume | mm POM
(polyoxymethylene, graphited) |
|---|---|
| Total wall area density |
453 mg/cm2 |
| Dimension of sensitive volume |
radius 22 mm |
| Central electrode | graphite coated PMMA, diameter 4.2 mm |
Ion collection efficiency at nominal voltage
| Ion collection time | 4.5 ms |
|---|---|
| Max. dose rate for ≥ 99 % saturation ≥ 90 % saturation |
29.4 Sv/h 294 Sv/h |
| Max. dose per pulse for ≥ 99 % saturation |
26 µSv |
Useful Ranges
| Chamber voltage | ± (200 … 400) V |
|---|---|
| Radiation quality | 25 keV … 1.3 MeV |
| Temperature | (10 … 40) °C (50 … 104) °F |
| Humidity | (10 … 80) %, max 20 g/m3 |
| Air pressure | (700 … 1060) hPa |
Parts
TN32005 Spherical chamber TK-30, connecting system BNT
TW32005 Spherical chamber TK-30, connecting system TNC
TM32005 Spherical chamber TK-30, connecting system M
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