CSIRO-UNSW PhD Project

Development of a Real-Time Toxic Elements Analyser using X-ray Fluorescence

 
Supervisors:
CSIRO:  Dr Yves Van Haarlem -  yves.vanhaarlem@csiro.au
UNSW:  Dr Pramod Koshy -  koshy@unsw.edu.au & Prof Charles Sorrell - C.Sorrell@unsw.edu.au
 

Introduction

The following are the details of an opportunity to undertake a Ph.D. through a collaborative research between CSIRO and UNSW. This project will be conducted with the Sensing and Sorting Research Group based at Lucas Heights. Our main research activities involve the development of novel instruments for minerals and security industry applications. We focus on carrying new ideas from the basic research stage through to industrial demonstration and commercialisation. Our group comprises a mix of students, postdoctoral fellows, scientists, and mechanical, electronic and software engineers.
 
The student would join the X-rays team, who focus on inventing, designing and building X-ray and nuclear-based measurement and imaging systems. The projects involve a diverse range of skills, including:

• Computer modelling of radiation, using Monte Carlo tools;
• Designing, building and operating experimental equipment;
• Research high purity materials and robust, radiation hard X-ray windows
• Investigating novel methods for measuring trace element using X-ray fluorescence
• Using radiation sources and detectors, including X-ray tubes and high-resolution solid-state detectors;
• Data collection and analysis using python; and
• Writing publications and a research thesis.
 
The student will be based at CSIRO’s Lucas Heights laboratories.

 

There are also excellent opportunities to continue with CSIRO following successful completions as a Postdoctoral Fellow or Research Scientist.


Profile


The ideal candidate should possess a physics/materials science background with good mathematical knowledge, strong interest in conducting experimental and analytical work in the laboratory in terms of sample preparation, material fabrication and characterisation, computer simulation. The candidate should also possess good knowledge of at least one scripting or programming language, preferably Python.

The candidate should also obtain an Australian Government Research Training Program (RTP) Scholarship (previously APA or equivalent). A top-up may be provided by CSIRO.

International students with equivalent scholarships are eligible to apply, but security clearance can impact on their selection and may cause delays to the commencement of the work. 


Project Background


In today’s ever growing cities, the need for accurate real-time monitoring of toxic elements in food, water and soil becomes very important.  At the moment some of the required accuracies cannot be met with existing analysers. We - the X-ray team that is part of Sensing and Sorting, Mineral Resources Business Unit, CSIRO - developed a technology called UltraGold (UG) that enables real-time detection of gold at parts-per-billion level in mineral processing streams also called tailings. 
 
This project involves the further development of this technology in order to push detection limits for toxic elements. We aim for markets like the Chinese one where the need for environmental control is rising and hence the requirement for the proposed analyser.
Challenge

Our team focusses on mineral processing applications but we believe that the UG technology can be used as a basis for the development of a table top size XRF analyser that is able to detect toxic elements like lead, arsenic, selenium and cadmium. We want to focus on soil because it is the hardest sample type to analyse as it often contains a lot of interfering elements for which a correction has to be applied. If an analyser can be developed for soil, the same analyser can be used for most other samples like water, rice, tobacco, tea, etc. Moreover, when detecting low concentrations (at parts-per-billion level), it is important that the analyser itself does not contain elements it tries to measure. Materials have to be researched for their purity and robustness. Another important part of the analyser is the X-ray window: it is the interface between the sample and the analyser.  This material needs to be strong, thin and radiation hard. 



Project Outline

 
First, the candidate will start with a study to establish what elements the new analyser should focus on and gain proficiency with XRF analysis in terms of relevant physics, X-ray tubes, detectors, typical geometries, software, etc. In this stage clear requirements will be set for the desired analyser.

In the first year of the project, the candidate will focus on the analyser design, including material for the holding structure and X-ray window. The X-ray team uses in-house simulation software based on EGS to simulate X-ray interactions with matter. The candidate will use this software to simulate several designs to find the optimal performing analyser.

The second year is about the construction of the prototype, characterizing parts like optics (when used) and material impurity interference, writing the analysis software, and calibration of the detector with standards.

The third year will focus on testing the detector with known and blind samples to establish the analyser’s performance and come up with improvements through experience.