GLP0 pages

ORTEC®
GLP Series Planar
HPGe Low-Energy Detector
Product Configuration Guide
• Excellent energy resolution in the 3 to 300 keV range
• Active area from 30 to 1000 mm2
• PopTop flexibility
• Unequaled timing performance
• Detectors larger than 36-mm diameter available
• Available with special feedback resistor for high-rate applications
• POF preamplifier option for superior energy resolution and high count rate at
low energies
The ORTEC GLP Series Planar Low-Energy Photon Spectrometer (LEPS) is a
small-area, high-purity germanium photon spectrometer for use in applications
over the energy range from 3 to ~300 keV.
Available in diameters from 6 to 36 mm, the LEPS offers exceptional energy
resolution for low and intermediate energies. At low energies in nuclear structure
physics GLP detectors are irreplaceable because of their excellent timing performance
(see Table 1).
A cross sectional drawing of a 16-mm LEPS is shown in Figure 1.
The Following Specifications are Provided for Each Model
GLP Detector
• Active crystal diameter and depth.
• Energy resolution at 5.9 keV photons from 55Fe at optimum shaping time
unless the window material prohibits this energy.
• Energy resolution at 122 keV photons from 57Co at optimum shaping time.
Configuration Guidelines
PopTop or Streamline (non-PopTop) Configuration
The essence of a PopTop detector system is that the HPGe detector element cryostat, preamplifier, and high voltage filter are housed
in a detector “capsule” which is then attached to an appropriate cryostat (Figure 2.)
In so called Streamline systems, the detector
capsule in 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.
The actual PopTop capsule has its own vacuum.
It can be mounted on any of the available
cryostats, cryostat/dewar combinations, or the
X-COOLER II mechanical cooling system.
Fig. 1. 16-mm Diameter, 10-mm Deep GLP Detector.
Table 1. Timing at Low Energies with 10 cm2
Active Area Planar Detectors*.
Source Energy (keV) Time Resolution(ns)
22Na 20 ±10
100 ±10
511 ±5
20 ±2
8.5 ±1
4.5 ±0.2
133Ba 31 ±3
81 ±3
85 ±5
356 ±5
19 ±2
Isomer
11 ±1
6.0 ±0.5
152Eu 41 ±3
122 ±5
125 ±5
344 ±5
779 ±5
15 ±1
Isomer
6.5 ±0.5
5.0 ±0.2
3.8 ±0.3
*Data courtesy of Dr. Kim Lister, Argonne National Lab.
Fig. 2. Diagram of PopTop Detector.