- Compact (6-1/2 in. x 20 in. maximum dimensions)
- Lightweight detector/dewar package 8–10 lb, stainless steel shroud 25 lb, aluminum shroud ∼12 lb
- 1/4 in. Swagelock fittings for cooling endcap (optional)
- Foam-rubber insulation reduces shock
- External connections for in-situ LN2 refilling
- Military specification electrical connections
- Water resistant
- Available with Be or Al end cap
The ORTEC Pipe Gage Monitor (PGM-1) is designed to monitor fluid/vapor density in nuclear reactor coolant piping. Other applications include activated corrosion products monitoring, activation analysis of sulphur in coal slurry, and stack monitoring. In applications requiring high-resolution gamma-ray spectroscopy, such as reactor coolant pipe monitoring, a high-purity germanium (HPGe) radiation detector may be desirable. However, all germanium radiation detectors require liquid nitrogen (LN
2) cooling to operate. A special dewar (thermos vessel) was designed to fit the compact space requirements.
The reactor coolant pipe is subject to temperatures of up to 650°F within 0.5 inches of the detector window. To ensure adequate cooling protection under this environment, a cooling coil is built into the stainless steel endcap to circulate cold water as required. This small but rugged package is bolted to the coolant pipe via a flange.
The liquid nitrogen is refilled periodically through a separate automated filling system attached to the rear of the housing. The holding time of the LN
2 dewar is more than 16 hours. Electrical connections (preamp power, detector, H.V. bias, H.V. cutoff, amplifier output, test pulser input) to and from the detector package are made through a military specification connector. This compact (approximately 20-in. in length and 6-1/2 in. in diameter maximum) rugged radiation detector package can be operated either indoors or outdoors.