Thermo Scientific SAM12, Manual

Page: 115 / 176

Issue: 1.0 Technical Description - Physics
Thermo Fisher Scientific SAM12 User Manual 6-11
free space, (i.e. un-attenuated). The detectors were optimised
for each Isotope in the geometric centre of the measurement
cubicle.
Efficiencies are quoted “Centre” (geometric centre of
Measurement Volume).
and
3 inches (centre of Measurement Volume 3”
from floor)
Nominal Value quoted with maximum spread in brackets.
Door configuration has a small, usually insignificant, effect on
6 detector efficiencies.
Table 1 Standard SAM12 Standard Stainless Steel Liners
Variant Total
Bgnd
(typ)
60
Co (1.2
MeV)
137
Cs (662
keV)
137
Ba (356
keV)
10
μ
R/h
0.1
μ
Sv/h
3 inches Centre 3 inches Centre 3 inches Centre
4C-XD-
1L 350 cps 45%
(40-
48) 40%
(36-
44) 17%
(16-
20) 16%
(15-
19) 28%
(26-
31) 26%
(24-
28)
6C-2D-
1L 550 cps 57%
(55-
59) 53%
(51-
55) 24%
(22-
26) 23%
(21-
25) 38%
(36-
40) 36%
(34-
38)
6C-1D-
2L 350 cps 61%
(58-
65) 58%
(56-
60) 26%
(24-
28) 25%
(23-
27)
—
—
Low Energy Variants have 6 detectors, 2 inches (50 mm) lead
shielding and an additional 2mm Copper X-ray absorber.
(
Note : mu-metal magnetic shielding is removed for maximum
sensitivity).
Table 2 Low Variant SAM12 Energy Variants
Total Bgnd
241
Am (59 keV)
3 inches Centre
SAM12LP – 6C-1D-2L
(Plastic Liners) 1000 cps 13½%
(12-15) 13%
(12-15)
SAM12LA – 6C-1D-2L
(Aluminium Liners)
1000 cps
9%
9%
SAM12A – Standard
Stainless Steel Liners
Low Energy Variants