Features
- Ultra thin entrance window
- For low-energy photons from 8 keV to 35 keV
- Sensitive volume 0.02 cm3, vented to air
- Radioactive check device (option)
The 23342 soft X-ray chamber is the golden standard for absolute dose measurements in low-energy photon beams as used in superficial radiation therapy. Correction factors needed for the determination of absorbed dose to water are available. The chamber is designed for the use in solid state phantoms.
Specifications
| Type of product | vented plane parallel ionization chamber acc. IEC 60731 |
|---|---|
| Application | absolute dosimetry in low-energy photon beams |
| Measuring quantities | absorbed dose to water, air kerma, exposure |
| Reference radiation quality | 30 kV, HVL 0.37 mm Al (T30) |
| Nominal sensitive volume | 0.02 cm3 |
| Design | not waterproof, vented |
| Reference point | in chamber center of entrance foil underside |
| Direction of incidence | perpendicular to chamber plane |
| Nominal response | 1 nC/Gy |
| Long-term stability |
≤ 1 % per year |
| Chamber voltage | 300 V nominal ± 500 V maximal |
| Directional response | ≤ ± 1 % for chamber tilting up to ± 20° |
| Leakage current | ≤ ± 10 fA |
| Cable leakage | < 1 pC/(Gy·cm) |
Materials and measures
| Entrance foil | 0.03 mm PE |
|---|---|
| Total window area density | 2.76 mg/cm2 |
| Sensitive volume | radius 1.5 mm depth 1 mm |
Ion collection efficiency at nominal voltage
| Ion collection time | 30 µs |
|---|---|
| Max. dose rate for ≥ 99.5 % saturation ≥ 99.0 % saturation |
175 Gy/s |
| Max. dose per pulse for ≥ 99.5 % saturation ≥ 99.0 % saturation |
1.8 mGy 4.5 mGy |
Useful Ranges
| Chamber voltage | ± (100 … 400) V |
|---|---|
| Radiation quality | (8 … 35) keV X-rays |
| Field size | (1 x 1) cm2 … (40 x 40) cm2 |
| Temperature | (10 … 40) °C (50 … 104) °F |
| Humidity | (20 … 80) %, max 20 g/m3 |
| Air pressure | (700 … 1060) hPa |
Options
T48010 Radioactive check device 90Sr
T23238 Chamber holding device for check device
Parts
TN23342 Soft X-ray chamber 0.02 cm3, connecting system BNT
TW23342 Soft X-ray chamber 0.02 cm3, connecting system TNC
TM23342 Soft X-ray chamber 0.02 cm3, connecting system M
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