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PopTop Cryostats and Dewars
Non-PopTop Cryostats and Dewars
Cryostat and Dewar Drawings
Germanium
Detector Stocklist |
GEM High-Purity Germanium (HPGe) Coaxial Detectors
(in PopTop
Capsule)
For computer-based analysis of complex spectra requiring the best in
resolution, peak-to-Compton ratio, peak shape, and efficiency:
- Large stocklist at all times
- Efficiencies to 150%, higher on request
- New "Application-Tuned" PROFILE Series available
- PopTop flexibility
- Excellent energy resolution
- Excellent peak symmetry
- Automatic high-voltage shutdown protects preamplifier input FET
- Indicator warns of excessive counting rate
- PLUS preamplifier option for ultra-high-rate applications
Figure 8. Configurations of Coaxial Germanium Crystals. |
GEM Series Germanium (HPGe) detectors are manufactured with
ORTEC’s own Germanium and represent the state of the art in "conventional",
i.e., outer contact Li diffusion and inner contact ion-implanted
Germanium coaxial detectors
(Fig. 8). Because of the superior quality of ORTEC’s Germanium material, GEM detectors
feature the best available energy resolution, peak-to-Compton ratios, and peak symmetry
ratios at 1.33 MeV. Note that energy resolution and symmetry ratios are warranted to two
decimal places.
The high degree of symmetry resulting from the superior material and
processes used in manufacturing ORTEC detectors make them ideal for computer-based
analysis where the detector peak shape is of paramount importance.
ORTEC is renowned for delivering detectors with measured specifications
substantially better than the warranted values.The geometrical features of the GEM detector that result in such
excellent peak shape are: (1) by far the world’s best germanium crystals, (2) deep
holes used for making the central contact, (3) "bulletized" (rounded) front
corners on the detector for uniform electric field. No one makes detectors as well as
ORTEC.
ORTEC maintains a large stocklist of GEM detectors. Some of these have "super
specifications," that is, a warranted energy resolution better than the first
category GEM specifications.Unless otherwise specified, each GEM HPGe
coaxial detector is supplied in a PopTop capsule. A complete
detector assembly requires a cryostat and a dewar.
Options of Interest
Ordering InformationGEM Germanium (HPGe) Coaxial Detector (Non-PopTop or PopTop)
For GEM Detector in PopTop capsule†, add "P4"
to the model no. [e.g., GEM90P4-95].
Endcap diameter must be specified, see Endcap Diameter Options
[e.g., GEM10-70,
GEM35P4-76]
FW.02M/FWHM specification is Typical, all other
specifications are warranted.
|
Model No. |
Efficiency (%) |
Resolution |
Peak-to-Compton Ratio |
Peak Shape* |
Endcap Diameter Options |
|
@122 keV (keV) |
@1.33 MeV (keV) |
FW.1M/ FWHM |
FW.02M/**
FWHM |
| GEM150 |
150 |
1.30 |
2.3 |
90:1 |
2.0 |
3.1 |
-108 |
| GEM140 |
140 |
1.30 |
2.2 |
90:1 |
2.0 |
3.1 |
-108 |
| GEM130 |
130 |
1.30 |
2.1 |
90:1 |
2.0 |
3.1 |
-108 |
| GEM120 |
120 |
1.30 |
2.1 |
86:1 |
2.0 |
3.1 |
-108 |
| GEM110 |
110 |
1.30 |
2.1 |
85:1 |
2.0 |
3.0 |
-95 |
| GEM100 |
100 |
1.20 |
2.1 |
83:1 |
2.0 |
3.0 |
-95 |
| GEM90 |
90 |
1.20 |
2.0 |
80:1 |
2.0 |
3.0 |
-95 |
| GEM80 |
80 |
1.10 |
2.0 |
77:1 |
2.0 |
3.0 |
-95 |
| GEM75 |
75 |
1.10 |
2.0 |
77:1 |
2.0 |
3.0 |
-95 |
| GEM70 |
70 |
1.00 |
2.0 |
75:1 |
2.0 |
3.0 |
-95 |
| GEM65 |
65 |
1.00 |
1.95 |
73:1 |
1.9 |
3.0 |
-83, -95 |
| GEM60 |
60 |
1.00 |
1.95 |
70:1 |
1.9 |
3.0 |
-83, -95 |
| GEM55 |
55 |
1.00 |
1.90 |
67:1 |
1.9 |
2.8 |
-83 |
| GEM50 |
50 |
0.90 |
1.90 |
66:1 |
1.9 |
2.6 |
-83 |
| GEM45 |
45 |
0.90 |
1.90 |
64:1 |
1.9 |
2.6 |
-76, -83 |
| GEM40 |
40 |
0.87 |
1.85 |
64:1 |
1.9 |
2.6 |
-76, -83 |
| GEM35 |
35 |
0.85 |
1.85 |
62:1 |
1.9 |
2.6 |
-70, -76, -83 |
| GEM30 |
30 |
0.85 |
1.85 |
60:1 |
1.9 |
2.6 |
-70, -76, -83 |
| GEM25 |
25 |
0.82 |
1.85 |
56:1 |
1.9 |
2.6 |
-70, -76, -83 |
| GEM20 |
20 |
0.82 |
1.80 |
52:1 |
1.9 |
2.6 |
-70 |
| GEM15 |
15 |
0.82 |
1.80 |
46:1 |
1.9 |
2.6 |
-70 |
| GEM10 |
10 |
0.80 |
1.75 |
41:1 |
1.9 |
2.6 |
-70 |
| Options |
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| -RB |
Reduced background PopTop Capsule with Carbon Fiber Endcap, add "-RB" to the
model number [e.g., GEM10P4-70-RB] |
| -PLUS |
Ultra-high-count-rate Preamplifier, add "-PLUS" to
the model number [e.g., GEM10P-70-PLUS for PopTop or GEM10-70-PLUS for Non-PopTop] |
| SMART-1-P |
SMART-1 detector option for positive bias detector. To order,
add SMART-1-P as a separate line item. |
†All GEM PopTop detector capsules include sealed detector element,
preamplifier, and high-voltage filter. Useful energy ranges, from 40 keV to 10 MeV.*FWHM = Full Width at Half Maximum; FW.1M = Full Width at One-Tenth
Maximum; FW.02M = Full Width at One-Fiftieth Maximum; total system resolution for a source
at 1000 counts/s measured in accordance with ANSI/IEEE Std. 325-1996, using ORTEC standard
electronics.
**Typical Value.NOTE: For those familiar with HPGe detector specifications, you will
notice that ORTEC now offers ONLY "first category" detector specifications.
Recent process improvements now make this possible. |
