For applications requiring both portability and flexibility of use, the MAC (multi-attitude cryostat) is the answer. The unique fill and vent system employed by the MAC cryostat allows operation of the detector in any orientation without LN2 spillage even when the Dewar is full. The small size, lightweight, and ruggedness of the unit permit use of the unit in field conditions. The slimline detector chamber allows the unit to be shielded very effectively for use in low level counting applications.
The MAC detector consists of a Dewar having two fill and vent ports arranged so that one of the ports is the vent, regardless of the Dewar's orientation. This allows the Dewar to be operated in the horizontal position, vertically uplooking, or vertically downlooking, without loss of LN2.
A single port version of the MAC and Big MAC cryostat is available on special order. This version has half the capacity and holding time of the standard product. A gravity-feed supply Dewar/stand is available for the single port cryostat. The single port cryostat is compatible with other brands, and it holds LN2 in all orientations which may be important in some applications, e.g. for use in a submarine (see Mirion Model 7411).
The detector/preamp includes a sensor which provides a signal when the LN2 is depleted. This output can be used to shut down the bias supply, to operate an alarm, or both.
The standard MAC unit features the Mirion Slimline™ Cryostat option in which a Mirion preamplifier is packaged behind the detector chamber within the confines of the 80 mm diameter snout. The Slimline cryostat allows the detector to be installed in a shield with very little difficulty and with efficient use of shielding material. The snout is long enough to reach through 10-15 cm of shielding material and still accommodate Marinelli beaker samples.
A flanged version of the MAC cryostat is also available. This version makes use of a conventional box style preamplifier having bulkhead connectors (rather than pigtail connectors) and is somewhat more compact than the Slimline version.
The MAC unit comes with detachable carrying handle assembly. With the carrying handle assembly removed, there are no obstructions beyond the outer diameter of the Dewar, and the unit can be readily installed in other scientific apparatus such as whole-body counters, scattering chambers or low-level counting systems.
Both manual and automatic refill systems are available for use with the MAC. Since the MAC has separate fill and vent ports, the LN2 supply and the vent lines can be made gas tight, thus avoiding the hazards of cold N2 or LN2 to either personnel or adjacent equipment.
The MAC cryostat is available as an option with most of the High Purity Germanium detectors offered by Mirion. Consult the Canberra™ Catalog for information on the wide variety of detectors that are available from Mirion.
Worldwide Support and Sales for Spectroscopy and Waste Characterization products