TY - JOUR
T1 - The new CSIRO-GEMOC nuclear microprobe
T2 - First results, performance and recent applications
AU - Ryan, Chris G.
AU - Jamieson, David N.
AU - Griffin, William L.
AU - Cripps, Gary
AU - Szymanski, Roland
PY - 2001/7
Y1 - 2001/7
N2 - A new nuclear microprobe (NMP) has been designed and built at the CSIRO featuring: (1) a quadrupole quintuplet lens system with a demagnification of 67 and 80 mm working distance; (2) a close detection geometry for Ge X-ray, 30% Ge γ-ray and particle detectors; (3) a high-quality normal-viewing microscope, coaxial with the beam; (4) computer-controlled beam-shaping and 5-axis sample stage; (5) scanning for imaging to >5×2 mm2; and (6) a vibration isolated mounting. Most design goals have been successfully achieved. On the first day of operation, a spot size of 1.3μm was obtained at a beam current of 0.5 nA, suitable for fluid inclusion analysis and imaging. The spot size grows to just 1.8μm at 8 nA (3 MeV protons) and 2μm at 10 nA, despite the low brightness of our tandem accelerator (1.2pA μm-2 mrad-2 MeV-1). This beam current is ideal for geological samples with PIXE detection limits down to 0.2 ppm (Br) achieved in silicates (39 pp b (Ge) in diamond at 22-25 nA) in quantitative, high resolution, trace element images.
AB - A new nuclear microprobe (NMP) has been designed and built at the CSIRO featuring: (1) a quadrupole quintuplet lens system with a demagnification of 67 and 80 mm working distance; (2) a close detection geometry for Ge X-ray, 30% Ge γ-ray and particle detectors; (3) a high-quality normal-viewing microscope, coaxial with the beam; (4) computer-controlled beam-shaping and 5-axis sample stage; (5) scanning for imaging to >5×2 mm2; and (6) a vibration isolated mounting. Most design goals have been successfully achieved. On the first day of operation, a spot size of 1.3μm was obtained at a beam current of 0.5 nA, suitable for fluid inclusion analysis and imaging. The spot size grows to just 1.8μm at 8 nA (3 MeV protons) and 2μm at 10 nA, despite the low brightness of our tandem accelerator (1.2pA μm-2 mrad-2 MeV-1). This beam current is ideal for geological samples with PIXE detection limits down to 0.2 ppm (Br) achieved in silicates (39 pp b (Ge) in diamond at 22-25 nA) in quantitative, high resolution, trace element images.
KW - Geology
KW - Nuclear microprobe
KW - PIGE
KW - PIXE
KW - Proton microprobe
UR - http://www.scopus.com/inward/record.url?scp=0035387962&partnerID=8YFLogxK
U2 - 10.1016/S0168-583X(01)00548-1
DO - 10.1016/S0168-583X(01)00548-1
M3 - Article
AN - SCOPUS:0035387962
SN - 0168-583X
VL - 181
SP - 12
EP - 19
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
IS - 1-4
ER -