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The CSIRO-GEMOC Nuclear Microprobe

System Overview

Lens System

Quadrupole Design

Quintuplet Configuration

Beam Shaping Controls

Scanning, Beam Deflection


Data Acquisition and Analysis

Target Chamber

Quadrupole picture

Return to NMP microanalysis

Quadrupole Design

The quadrupole yokes are shaped with pole-tip extensions, which bring the quadrupole fields 30 mm closer to the target. Also, to accommodate unrestricted detector access at 135° to the beam, the yokes have cut-outs between poles for symmetric detector ports. The cut-outs permit these ports to fit between coil windings, and four cut-outs are used to maintain four-fold symmetry. The result is an effective working distance of 80 mm despite a large yoke outer diameter of 270 mm and a bore of 14 mm [1,2].

New quadrupole design

A CSIRO-GEMOC Nuclear Microprobe quadrupole singlet showing these new design features, and developed as a collaboration between the CSIRO and the MARC group of the University of Melbourne.

These new quadrupole lens elements are being manufactured by, and are available through, MARCO, Melbourne.

[1] C.G. Ryan and D.N. Jamieson, "A high performance quadrupole quintuplet lens system for the CSIRO-GEMOC Nuclear Microprobe", Nucl. Instr. Meth. B158 (1999) 18-23.

[2] C.G. Ryan, D.N. Jamieson, W.L. Griffin, S.H. Sie, G. Cripps and G.F. Suter, "The new CSIRO-GEMOC Nuclear Microprobe: A new highly integrated design for geoscience applications", proc. 10th Australian Conf. on Nuclear Techniques of Analysis, Canberra, ISSN 1329-8437 (1997) NTA/VSA8.

For further information contact: Dr. Chris Ryan via email: (
Phone +61-3-9905 9087
Fax orders +61-7-3327 4455
CSIRO Exploration and Mining
Bayview Road, Clayton VIC 3168
CSIRO Australia

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