Features
- Useful for measurements in small and large photon fields
- Excellent spatial resolution
- Minimized energy response for field size independent measurements up to 40 cm x 40 cm
The 60008 Dosimetry Diode P is ideal for dose measurements in small photon fields as encountered in IORT, IMRT and stereotactic beams. The excellent spatial resolution makes it possible to measure very precisely beam profiles even in the penumbra region of small fields. The superior energy response enables the user to perform accurate percentage depth dose measurements which are field size independent up to field sizes of (40 x 40) cm2. The waterproof detector can be used in air, solid state phantoms and in water.
Specifications
| Type of product | p-type silicon diode |
|---|---|
| Application | dosimetry in radiotherapy beams |
| Measuring quantity | absorbed dose to water |
| Reference radiation quality | 60Co |
| Nominal sensitive volume |
0.0025 mm3 |
| Design | waterproof, disk-shaped sensitive volume perpendicular to detector axis |
| Reference point |
on detector axis, 2 mm from detector tip |
| Direction of incidence | axial |
| Nominal response | 175 nC/Gy |
| Dose stability |
<10 %/1kGy at 23MV
<1 %/10 kGy at 60Co |
| Temperature response | 0.15 %/K |
| Energy response | at higher depths than dmax, the percentage depth dose curves match curves measured with ionization chambers within ± 0.5 % |
| Detector bias voltage | 0 V |
| Signal polarity | negative |
| Directional response in water | le; ± 0.5 % for rotation around the chamber axis, ≤ ± 1 % for tilting < ± 20° |
| Leakage current | ≤100 fA |
| Cable leakage | < 1 pC/(Gy·cm) |
Materials and measures
| Entrance window |
1 mm RW3, 1.045 g/cm3 1 mm epoxy |
|---|---|
| Total window area density | 221 mg/cm2 |
| Water-equivalent window thickness | 2.2 mm |
| Sensitive volume |
radius 0.56 mm depth 2.5 µm |
| Outer dimensions |
diameter 7 mm, length 47 mm |
Useful Ranges
| Radiation quality | 60Co … 25 MV photons |
|---|---|
| Field size | (1 x 1) cm2 … (40 x 40) cm2 |
| Temperature | (10 … 40) °C (50 … 104) °F |
| Humidity | (10 … 80) %, max 20 g/m3 |
Parts
TN60008 Dosimetry Diode P, connecting system BNT
TW60008 Dosimetry Diode P, connecting system TNC
TM60008 Dosimetry Diode P, connecting system M
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