New articles published: V. 14 n. 2 (2026)

Automation of Sample Handling for ORTEC’s Lead-Shielded High-Purity Germanium Gamma-Ray Detector

Abstract: Gamma spectroscopy is a non-destructive technique for identifying and quantifying radionuclides in environmental samples. High-purity germanium (HPGe) detectors are commonly used for these analyses. To minimize background radiation from sources other than the sample, the detector is housed in a lead shield. ORTEC’s low-background shield, weighing approximately 1180 kg, poses challenges for automation, making such systems rare and commercially expensive. Additionally, HPGe detectors require cooling to cryogenic temperatures, typically achieved using liquid nitrogen (LN₂). The drawbacks of LN₂ include its high cost and the limited duration of a 30 L LN₂ charge (around 14 days), regardless of detector operation. An autosampler, an automated sample-handling system, optimizes LN₂ usage by enabling sample changes during idle periods. In this work, we developed a cost-effective and efficient autosampler incorporating a “pick and place” robot and a pneumatic circuit for sample manipulation, linear actuators for automated door operation, and an electronic system integrated with “Maestro” (ORTEC’s spectroscopy software) via a custom-developed Python interface. This system integrates mechanical design, electronics, and programming to enhance efficiency, optimize LN₂ usage and reduce downtime, thereby improving overall operational performance. Read full article.