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ACTINIDE-85 Germanium (HPGe) Lung Monitor Detector
The unique detector design combines large area and excellent energy resolution across a wide range of energy, with excellent peak shape, so important in analysis of complex spectra. The result is excellent sensitivity for the detection of small amounts of actinides such as uranium, plutonium, and americium, as well as higher energy fission products and naturally-occurring radioisotopes, in a distributed source such as the human lung. The large frontal area (>54 sq cm) of ACTINIDE-85 provides high geometrical detection efficiency and superior resolution performance in the lower energy range of actinides such as Pu, Am and U, below around 400 keV, while the crystal depth of 30 mm means good stopping power and excellent relative efficiency at higher energies. The excellent warranted energy resolution at 1.33 MeV, combined with exceptionally good peak shapes, means that the ACTINIDE-85 is the ideal detector solution for analysis of fission products as well.In lung burden measurements, large diameter detectors allow better coverage of the lung; with ACTINIDE-85, critically important energy resolution is maintained. The special mechanical construction of the cryostat allows two, three, or four ACTINIDE-85 detectors to be placed very close to each other and in contact with the subject. This configuration gives the maximum possible detector efficiency for human lungs. The detector cryostat is made of selected and qualified low background material, based not only on radioactive background characteristics, but also on long-term reliability. The detector endcap is made of an ultra-low background, high-strength carbon fiber composite which provides greater than 85% transmission for photon energy above 15 keV and nearly 100% transmission for photon energy above 20 keV. To further assure and verify low background quality, each detector is placed inside a graded-Z shielding and a background spectrum is taken for 100,000 seconds after assembly. This spectrum is delivered with the detector. PositioningORTEC ACTINIDE-85 detectors may be ordered in a variety of configurations to meet a variety of requirements for lung burden, body burden, and whole-body counting programs. ORTEC lung burden assessment systems allow independent detector positioning which provide for optimum detector placement and measurement efficiency. In general, positioning mechanisms should be made of carefully screened low-background materials and designed for ease of use and reliability. Cryostat and Dewar The standard ACTINIDE-85 is supplied with a 3.5L "high fill" dewar. Which provides a typical holding time of 48 hrs. A turn-key automatic LN2 fill system is also available as an option. ACT85-FILL OptionThe ACT85-FILL option is an advanced, microprocessor-based solution designed to provide reliable level monitoring and control of LN2. It is capable of supporting two ACTINIDE-85 detectors. If more than two detectors are to be used, multiple fill systems may be used. The unit operates by measuring sensor capacitance, which is directly related to the liquid level in the sensor. The system consists of the controller, sensors, and connecting coaxial cables. Cryogenic solenoid valves operated by the controller are included. All calibration data is password protected to prevent unauthorized modification and is stored in non-volatile memory. In most cases, factory calibration is included, but for highest accuracy the system can be field calibrated after installation is complete. The ACT85-FILL system is supplied complete, except for the bulk LN2 storage tank. It comprises:
X-COOLER II Mechanical Cooling Option The ORTEC X-COOLER II can be employed as an alternative to liquid nitrogen to cool the ACTINIDE-85 detector. The use of LN2 is costly, time consuming, and (of particular concern for lung burden assessment) is potentially hazardous. In addition, the presence of LN2 can be intimidating to personnel. X-COOLER II is a proven, economical alternative to LN2 for whole-body counting. It can be shown that the savings in LN2 alone will mean that the investment in the X-COOLER II is recovered in a timescale as short as one year. Specifications
1Smaller crystal dimensions are available. Contact your ORTEC Sales Representative or the Main Factory. 2FWHM = Full Width at Half Maximum; FW0.1M = Full Width at One-tenth Maximum; FW.02M = Full Width at One-Fiftieth Maximum; total system resolution for a source at 1000 counts per second measured in accordance with ANSI/IEEE Std. 325-1996, using ORTEC standard electronics. 3Measured at optimum shaping time using ORTEC analog or digital electronics. 4The proprietary contact employed by the ACTINIDE-85 detector offers exceptionally high transmission at energies below 40 keV. Some instability in transmission may occur below 20 keV if stored uncooled at room temperature for extended periods of time (20–25°C or above). It is therefore recommended that the ACTINIDE-85 detector be kept cold, limiting the exposure to elevated ambient storage temperatures for applications which demand minimally varying efficiency below 20 keV. Ordering Information
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