GWL (Well) P-type Reverse Coaxial Radiation Detectors
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For Analysis of Small, Low-Activity Samples • • • • • • • GWL Series Coaxial HPGe Detector Product Configuration Guide High absolute counting efficiency for small samples Active Volumes to 400 cc Unique ion-implanted blind well Resolution specified with source inside the well Spectroscopy from 10 keV to 10 MeV Near 4  geometry Extra-large well (1.55 x 4.0 cm) standard ORTEC’s High-Purity Germanium (HPGe) Well Detectors offer high absolute counting efficiency for radiochemical analysis and low-level gamma-ray spectroscopy. The unique ion-implanted detector well has an ultra-thin dead layer (only 0.3 µm thick), and therefore provides the most extensive useful energy range (10 keV to 10 MeV). Unlike other Well detectors that have a hole all the way through the germanium crystal, ORTEC’s Well Detectors have a “blind hole” with at least 5 mm of active germanium at the bottom of the hole (Fig. 1). This near 4  geometry provides the maximum absolute counting efficiency available. The large well (1.55-cm-diameter and 4.0-cm-long) accommodates an extensive range of sample sizes. Like all of ORTEC’s HPGe photon detectors, the HPGe Well detector may be stored or cycled repeatedly to room temperature without performance degradation. As specified in ANSI/IEEE Std. 325-1996, the resolution is measured with a point source inside the well, 1 cm from the bottom. Measurements of resolution outside the well can be deceiving. Fig. 1. Simplified Isometric View of HPGe Well Detector Cryostat. A typical curve of absolute efficiency in the well vs. photon energy is shown in Fig. 2. The Following Specifications are Provided for Each Model GWL Detector • Energy resolution at 1.33-MeV photons from 60Co at optimum shaping time. • Active Ge volume and well tube diameter. • Energy resolution at 122 keV photons from 57Co at optimum shaping time. Configuration Guidelines Streamline (non-PopTop) Configuration In so called Streamline systems, the detector capsule is NOT demountable. Detector capsule and cryostat share the same vacuum. In configuration terms, this requires a cryostat or cryostat/dewar selection with the cryostat having a matching diameter to the capsule endcap. A cryostat must always be ordered with a Streamline capsule, because they are integral. Fig. 2. Absolute Detection Efficiency in the Well vs. Photon Energy. [If a well detector is used as a general-purpose coaxial detector (a use not recommended by ORTEC), its relative efficiency at 25 cm can be determine

Steps to Configure Your ORTEC HPGe Detector 1) Configure the Detector Model • Ge Crystal active volume and well tube diameter • Endcap and window • Mount • Preamplifier • High Voltage Filter • Cable Package Options are available for the detector model that can change specific materials used in the construction of the detector endcap, cup, and mount. Preamplifier options are also available. 2) Configure the Cryostat/Dewar Model • Vertical Dipstick style (separate Dewar or Mobius Recycler) • Sidelooking designed to be oriented with the detector horizontal at the bottom of the dewar • “J”...

GWL Series Coaxial HPGe Detector Product Configuration Guide Streamline Detector Capsule Electronic Shroud Preamplifier is Resistive Feedback Preamplifier Outside Vacuum -HJ changes Preamplifier and High Voltage Filter to Remote and eliminates the Electronic Shroud Cup default is Al -LB-AWT and -XLB-AWT change to Cu Window (well tube) default is Al -LB-AWT and -XLB-AWT change to High Purity Al High Voltage Filter -XLB-AWT extends capsule by ~1 inch to accommodate lead shield in cryostat Mount default is Al -LB-AWT and -XLB-AWT change to Cu Endcap default is Al -LB-AWT and -XLB-AWT change to...

Streamline Dimensional Data Streamline systems (detector capsule and cryostat) share the same vacuum, requiring a cryostat or cryostat/dewar selection with the cryostat having a matching diameter to the capsule endcap. A cryostat must be ordered with a Streamline capsule. The cryostat and dewar drawings that follow are to be used in conjunction with the accompanying tables of dimensions. Note: Cryostat/Dewar drawings are NOT to scale, see tables that follow for complete dimensions. Dimensions are for reference only and subject to change, if dimensional constraints are critical, contact the...

GWL Series Coaxial HPGe Detector Product Configuration Guide Note: Cryostat/Dewar drawings are NOT to scale, see tables that follow for complete dimensions. Dimensions are for reference only and subject to change, if dimensional constraints are critical, contact the factory. CFG-SJ, MOBIUS-B CFG-HJ, MOBIUS-B

• Dimensions are for reference only and subject to change. • If dimensional constraints are critical, contact the factory. GWL-120-10 120 cc active volume GWL detector with 10-mm diameter well tube and 70-mm diameter endcap. CFG-SV-70 Vertical “dipstick” style cryostat to fit 70-mm diameter endcap. DWR-30 30 liter top port dewar that accepts “dipstick” style cryostats. GWL-300-15-LB-AWT 300 cc active volume GWL detector with 15-mm diameter high purity Al (low-background) well tube and 95-mm diameter Cu endcap. CFG-SL-LB-95 Sidelooking cryostat and dewar to fit 95-mm diameter endcap with low...

Ordering Information • If dimensional considerations are critical, contact factory. • Cryostat and dewar or other cooling device are not included with detector and are required for operation. • A cryostat must be ordered with a Streamline detector. GWL Detector Options -LB-AWT Low-Background Detector with OFHC Cu Endcap and High Purity Al Well Tube, add “-LB-AWT” to the model number. Requires selection of a Low-Background LB cryostat. -XLB-AWT Extra-Low-Background Detector with OFHC Cu Endcap and High Purity Al Well Tube, add “-XLB-AWT” to the model number. Requires selection of a...