Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
22
D596.131.00/05 en
Device designation
Farmer chambers
ionization chambers, types 30010, 30013
Dimensions
refer to
Response
20 nC/Gy
Chamber voltage
n400 V
maximal ±500 V
Leakage current
≤ ±4 fA
Cable leakage
≤ 1 pC/(Gy∙cm)
Cable length
T30010: 1 m
T30013: 1.3 m
min. bending radius 20 mm (static)
min. bending radius 50 mm (for up to a maximum of 50 repetitions)
Maximum dose rate during
continuous radiation
(at nominal voltage)
99.0 % saturation
10 Gy/s
99.5% saturation
5 Gy/s
Maximum dose per radiation
pulse (at nominal voltage)
99.0 % saturation
0.91 mGy
99.5 % saturation
0.46 mGy
Ion collection time (at nomi-
nal voltage)
140 µs
Polarity effect
≤ ±0.5 % at
60
Co
Directional response
≤ ±0.5 % for rotation around the detector axis
≤ ±0.5 % for tilting by ±5° perpendicular to the detector axis
Energy response
≤ ±2 % (70 ... 280) kV, reference 200 kV
≤ ±4 % (200 kV ...
60
Co) reference
60
Co
Transient periods for
temperature equilibrium
pressure equilibrium
(2 ... 3) min/K
≤ 10 s
Pre-irradiation
none
Stabilization time
The response after 15 minutes and 2 hours differs by less than ±0.5 %
from the value after 1 hour.
Post irradiation leakage
signal drops to < 0.5 % within 5 s after irradiation
Stability
long-term stability: ≤ ±0.5 % per year
dose stability: ≤ ±1 % per 10 kGy
60
Co
