Download or read book Mechanically Cooled Large Volume Germanium Detector Systems for Nuclear Explosion Monitoring DOENA27323 1 written by E. L. Hull and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compact maintenance free mechanical cooling systems are being developed to operate large volume germanium detectors for field applications. To accomplish this we are utilizing a newly available generation of Stirling-cycle mechanical coolers to operate the very largest volume germanium detectors with no maintenance. The user will be able to leave these systems unplugged on the shelf until needed. The flip of a switch will bring a system to life in ~ 1 hour for measurements. The maintenance-free operating lifetime of these detector systems will exceed 5 years. These features are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems for Nuclear Explosion Monitoring. The Radionuclide Aerosol Sampler/Analyzer (RASA) will greatly benefit from the availability of such detectors by eliminating the need for liquid nitrogen at RASA sites while still allowing the very largest available germanium detectors to be reliably utilized.

Download or read book Waarom de derde orde written by and published by . This book was released on 1950 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanically Cooled Large Volume Germanium Detector Systems for Nuclear Explosion Monitoring written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compact maintenance-free mechanical cooling detector systems are being developed to operate large-volume (approximately 570 cubic cm, approximately 3 kg, 140% or larger) germanium detectors for field applications. These detector systems are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems. The Radionuclide Aerosol Sampler/Analyzer (RASA) nuclear explosion monitoring systems will benefit from the availability of such detector systems by allowing the very largest available germanium detectors to be utilized for the highest sensitivity measurements. To reliably provide such detector systems, three fundamental technical issues are being investigated: temperature, vacuum, and vibration. Two prototype detector systems (RASA 1 and RASA 2) have been developed, fabricated, and tested. The cryostats have been demonstrated to cool very large (slightly greater than 10(+)-cm long and 10-cm diameter) detectors to temperatures as low as 50 K. The vacuum design has been demonstrated to show no measurable degradation over long time periods. The detector systems have been demonstrated to successfully instrument high-purity germanium detectors. Microphonic noise from the vibrating cooler has been completely eliminated in one case, serving as a demonstration of the total detector system viability. Microphonic noise remains the largest technical issue for these detector systems. The third generation, RASA 3, design incorporates mechanical changes to eliminate microphonic noise issues.

Download or read book Mechanically Cooled Large Volume Germanium Detector Systems for Nuclear Explosion Monitoring written by Richard H. Pehl and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compact maintenance free mechanical cooling systems are being developed to operate large volume (~570 cm3, ~3 kg, 140% or larger) germanium detectors for field applications. We are using a new generation of Stirling-cycle mechanical coolers for operating the very largest volume germanium detectors with absolutely no maintenance or liquid nitrogen requirements. The user will be able to leave these systems unplugged on the shelf until needed. The flip of a switch will bring a system to life in ~1 hour for measurements. The maintenance-free operating lifetime of these detector systems will exceed five years. These features are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems for Nuclear Explosion Monitoring (NEM). The Radionuclide Aerosol Sampler/Analyzer (RASA) will greatly benefit from the availability of such detectors by eliminating the need for liquid nitrogen at RASA sites while still allowing the very largest available germanium detectors to be utilized. These mechanically cooled germanium detector systems being developed here will provide the largest, most sensitive detectors possible for use with the RASA. To provide such systems, the appropriate technical fundamentals are being researched. Mechanical cooling of germanium detectors has historically been a difficult endeavor. The success or failure of mechanically cooled germanium detectors stems from three main technical issues: temperature, vacuum, and vibration. These factors affect one another. There is a particularly crucial relationship between vacuum and temperature. These factors will be experimentally studied both separately and together to insure a solid understanding of the physical limitations each factor places on a practical mechanically cooled germanium detector system for field use. Using this knowledge, a series of mechanically cooled germanium detector prototype systems are being designed and fabricated. Our collaborators at Pacific Northwest National Laboratory (PNNL) will evaluate these detector systems on the bench top and eventually in RASA systems to insure reliable and practical operation.