VF HF-50 - Page 20

Technical specification
VF1807090083 EN revision 20
3.2. Surface Contamination Detector SCD-525
Detectors specification
Detected radiation
SCD-525A: Alpha in one channel
SCD-525B: Alpha + Beta in one channel
SCD-525C: Alpha / Beta in two channels
SCD-525D: Alpha + Beta + Gamma in one channel
SCD-525E: Alpha / Beta+Gamma in two channels
Scintillators
SCD-525A: ZnS(Ag) on acrylic glass, 1.5 mm thickness.
Surface density of the scintillator ZnS(Ag) (3.25 ± 0.25) mg∙cm
-2
SCD-525B: plastic scintillator of 0.25 mm thickness
SCD-525C: ZnS(Ag) on a plastic scintillator of 0.25 mm thickness.
Surface density of the scintillator (3.25 ± 0.25) mg∙cm
-2
SCD-525D: plastic scintillator of 5 mm thickness
SCD-525E: ZnS(Ag) on a plastic scintillator of 5 mm thickness.
Surface density of the scintillator ZnS(Ag) (3.25 ± 0.25) mg∙cm
-2
Photomultiplier
Diameter 25 mm with hemispheric window
High voltage source
(400 ÷ 1000) V with sensitive current limitation
Sensitive area of the
detector
(150 x 350) mm = 525 cm
2
(81.4 in
2
)
Window
Aluminized light-tight foil (3 x 0.29) mg∙cm
-2
Protective grid
Hexagonal grid, permeability 78 %
Dead time
Automatically compensated, typically 4.6 μs