Detectors
The target chamber accommodates two X-ray detectors, one Ge gamma-ray detector and up
to four particle detectors (two Canberra PIPS detectors initially).
The main X-ray detector is a Ge large area variety and is equipped with an
X-ray filter to attenuate intense major element lines. The chamber permits
a close geometry with the detector 16 mm from target [1,2]. This is complemented by a
second X-ray detector, a 10 mm2 Si(Li) (not shown above), to provide major element detection.
The principal X-ray detector is a Canberra Ultra LE Ge detector, an intrinsic Ge
detector with a 100 mm2 active area, a thickness of 10 mm and a measured energy
resolution of 143 eV (Mn Ka). The detector uses a Canberra 2060 digital signal
processor (DSP) which includes pile-up rejection and is capable of high counts rates,
by virtual of the digital filtering approach. The gamma-ray detector is a Canberra 30%
Ge detector, with a slim-line preamplifier configuration to insert into the chamber
0° port. The measured energy resolution is 1.9 keV (Co60 1.332 MeV). It uses a second
DSP, which includes pile-up rejection, as well as ballistic deficit correction [1].
[1] C.G. Ryan, D.N. Jamieson, W.L. Griffin, G. Cripps and R. Szymanski, "The New
CSIRO-GEMOC Nuclear Microprobe: First Results, Performance and Recent Applications",
Nucl. Instr. Meth. B181 (2001) 12-19.
[2] C.G. Ryan, D.N. Jamieson, W.L. Griffin and G. Cripps, "The CSIRO-GEMOC Nuclear Microprobe:
A high-performance system based on a new closely integrated design", Nucl. Instr. Meth. B158 (1999) 97-106.
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