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Compton-suppressed HPGe system for low-background counting
Complete system for very low-background gamma spectrometry. An NaI guard detector around the HPGe detector records photons scattered out of the germanium crystal, and coincident events are rejected so that the Compton continuum is reduced. This improves the minimum detectable activity, particularly for small samples such as air filters and petri dishes.
Download product sheet (PDF)All values with references – for tender documents
Specifications checked against the manufacturer’s documents on 2026-10-17
The number after each value refers to the source listed below. Values are as published by the manufacturer; the exact configuration is always confirmed in our quotation.
| Detector type | N-type HPGe (GMX) with carbon-fibre endcap, max. Ø83 mm (3.25 in), and low-background Al cup1 |
|---|---|
| Guard detector | 9 × 9 in NaI annulus (3.5 in I.D., 10.75 in O.D., FWHM ≤11% at 662 keV) and 6 × 2 in NaI plug (FWHM ≤7% at 662 keV)1 |
| Relative efficiency | 60% by default; other detector sizes up to 60% as options1 |
|---|---|
| Peak-to-Compton ratio | 1300:1 or greater (guaranteed, with the default GMX60 detector; averaged background region at 500 keV); smaller GMX detectors give lower values1 |
| Background rate | 0.5 cps or lower with rectangular or cylindrical shields1 |
| Maximum sample size | 3.5 in diameter × 3 in high (up to 750 mL)1 |
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| Included software | GammaVision; a computer is typically not included but can be provided on request1 |
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| Electronics | DSPEC-502A digital dual MCA (setup under 30 minutes) and 556H power supply for the NaI annulus1 |
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| Lead shielding | Cylindrical, 10 cm (4 in) reprocessed lead with inner liner (Tn/Cu); cavity 11 in diameter × 18 in high; optional cosmic veto with plastic scintillator1 |
The data comes from the manufacturer’s published documents. Manufacturers may change specifications; the current configuration and performance are confirmed in the quotation.
The number after each value refers to the source listed below. Values are as published by the manufacturer; the exact configuration is always confirmed in our quotation.
HPGe gamma detector
Digital gamma spectrometer / MCA
HPGe detectors for gamma spectroscopy
Planar HPGe gamma detector
We help you choose the right configuration, detector and accessories for your measurement task.
ORTEC (AMETEK)