CURRENT HPGe DSSD DESIGN & PERFORMANCE. 90 mm diameter, 10 mm thick. 55 cm2 active area. 16 x 16 orthogonal strips. 5 mm strip pitch (0.25 mm gaps) Mechanically cooled (75-85 K) Position Estimation. Sub-Strip interpolation. 530 μm x 530 μm pixel size.

2. Electrically Cooled Germanium System First electrically cooled HPGe detectors appeared on the market about 20 years ago, but were rather big and heavy and could not be used as portable NDA instrument that time. However, the technology has being improved and several years ago a new generation of portable electrically cooled HPGe …

cooled cryostat uses a CFC-free refrigerant and is well suited for use in industrial and laboratory applications. 5 10 20 50 100 200 500 1000 2000 10.0 1.0 0.1 ... Germanium Detectors Pulsed-Optical Reset preamplifiers are widely used on low energy detectors where resolution is of utmost consideration. Eliminating the feedback

The Compex detector is an electrically cooled, composite germanium detector that uses four coaxial, cubic-shaped, single-encapsulated germanium crystals. …

When germanium detectors are cooled with an electro-mechanical cooler, such as the ICS-P4 Integrated Cryocooling System for PopTop HPGe Detectors from ORTEC, there is a small possibility of an AC power failure causing detector damage. The supposed mechanism is that following the power failure, the system starts warming toward room …

We have successfully developed and fielded an electromechanically cooled germanium radiation detector (EMC-HPGe) at Lawrence Livermore National Laboratory (LLNL). This detector system was designed to provide optimum energy resolution, long lifetime, and extremely reliable operation for unattended and portable applications.

The RASA detector system will benefit from the availability of such detectors (Bowyer et al., 1997; Miley et al., 1998). Mechanical cooling of germanium detectors has historically been a difficult endeavor. The success or failure of mechanically cooled germanium detector systems arises from three main technical issues: temperature, vacuum, and

The purpose of this project was to develop a compact, modular multi-channel x-ray detector with integrated electronics. This detector, based upon emerging silicon drift detector (SDD) technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium (HPGe) detectors, without the …

in high-purity germanium detectors. In this fully automated setup, the detector under test is irradiated from the top with 661.660keV gammas, some of which Compton scatter inside the detector. The interaction points in the detector can be reconstructed when the scattered gammas are detected with a pixelated camera placed at the side of the ...

2. Methods. All measurements were performed using a mechanically-cooled HPGe detector from PHDs Co. (Knoxville, TN, USA). This double-sided strip detector was fabricated from a germanium crystal 90 mm in diameter and 10 mm thick using amorphous-semiconductor contacts (Hansen and Haller, 1977; Luke et al., 1992; Luke et al., …

resolution germanium detector for portable/field applications. The system weighs 6.8 kg and requires 40 watts of power to operate once the detector is cooled to its operating temperature. The detector is a 500 mm* by 20-mm thick low-energy configuration that gives a full-width at half maximum (FWHM) energy resolution of 523 eV at 122 keV,

Because germanium has relatively low band gap, these detectors must be cooled in order to reduce the thermal generation of charge carriers (thus reverse leakage current) to an …

the LN2 surrounding the detector array. In this configura-tion, the germanium detectors are directly cooled to a stable operating temperature by the LN2. Each detector string in CDEX-10 contains 3 point-contact germanium detectors denoted as Ge1-Ge3 from bottom to top, as shown in Figure 1. Each germanium crystal is ap-

High purity germanium remains the material of choice for the detection of photons in the range of MeV or higher, down to the hard X-ray range. Since the operation of HPGe-based detectors is possible only at or below the liquid nitrogen temperature, their advantage is mainly the resolution, which matches the Fano factor if appropriate cooled …

Germanium, due to its characteristics such as a narrow bandgap, high electron mobility, and high energy resolution, has emerged as an ideal material to produce various types of detectors [1,2,3].It has found widespread applications in fields such as nuclear physics, dark matter detection, and medical imaging [4,5,6,7,8].High-purity …

measured by using Hall Effect. Two different geometries of planar detectors were designed as shown in Figure 1. The thickness of their grooves and wings are fixed at 1.5 mm and 2 mm, respectively. The fabrication process is the same for the detectors with different geometries. Figure 1. Schematic of detector geometries for top view and cross ...

Parts of HPGe Detectors. The major drawback of germanium detectors is that they must be cooled to liquid nitrogen temperatures. Because germanium has relatively low band gap, these detectors must be cooled in order to reduce the thermal generation of charge carriers to an acceptable level. Otherwise, leakage current induced …

The next-generation mechanically-cooled germanium spectrometer has been developed. GeMini (GErmanium MINIature spectrometer) has been designed to bring high-resolution gamma-ray spectroscopy to a range of demanding field environments. ... The other is a 2000 mm/sup 2/ planar intrinsic germanium detector housed in an end …

@article{osti_894164, title = {Mechanically Cooled Large-Volume Germanium Detector Systems for Neclear Explosion Monitoring DOENA27323-2}, author = {Hull, E L}, abstractNote = {Compact maintenance free mechanical cooling systems are being developed to operate large volume high-resolution gamma-ray detectors for field …

Deciphering Radiation Alarms: Using High Purity Germanium Detectors for Nuclear Security; ... The need to keep the detector cooled, the comparatively high purchase and maintenance costs, and the required scientific expertise to interpret the data for security and safety purposes, present an impediment to widespread …

The ultra-low noise germanium test stand developed herein presents a unique and important opportunity for the study of fundamental physics of high purity germanium detectors and low noise electronics over a broad range of temperatures. Charge carrier mobility and leakage currents both improve at lower temperatures.

HPGe detector with LN2 cryostat Source: canberra. The major drawback of germanium detectors is that they must be cooled to liquid nitrogen temperatures. Because germanium has a relatively low band gap, these detectors must be cooled to reduce the thermal generation of charge carriers to an acceptable level. Otherwise, …

In this paper, methods are presented which can lower the electronic noise of these detectors. Through ultra-low vibration mechanical cooling and wire bonding of a …

of Mechanically Cooled High Purity Germanium (HPGe) Detectors at Elevated Temperatures." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Nuclear Engineering.

The signal-to-noise ratio (S/N) would be even smaller in doped material. Because germanium has a relatively low band gap, these detectors must be cooled to reduce the thermal generation of charge carriers (thus reverse leakage current) to an acceptable level. Otherwise, leakage current-induced noise destroys the energy resolution of the detector.

mechanically cooled germanium detectors stems from three main technical issues: temperature, vacuum, and vibration. These factors affect one another. A detailed analysis of these factors and their effects on detector performance was recorded last year (Hull et al., 2006). These factors are being studied in the laboratory at the most

First, excessive vibrations from conventional mechanical cooling (30–80 K) would significantly degrade the performance of low noise germanium detectors. Boiling liquid cryogens also cause microphonics which limit low noise performance at longer peaking times. Our detector system operated down to 30 K and eliminated microphonics …

germanium detectors for field use in rugged conditions. The hand-held "Detective" is an elegant example of a currently available mechanically cooled germanium detector system manufactured by Ortec (Keyser et al., 2003). This system uses a small Stirling-cycle cooler to cool a modest sized germanium detector to operating temperature

The germanium detector needs to be cooled, at least below 100–110 K, to reduce the thermal generation of charge carriers and associated noise. A lower temperature around 80 K is aimed at, as that mitigates trapping effects. These low temperatures are obtained inside a cryostat, which enables a direct thermal contact between the detector …

High purity germanium (HPGe) detectors o ff er excellent en- ergy resolution in a relatively lar ge (kg-scale) format with mate- rial purity suitable for ultra-low background experiments.