Dr Joshua Machacek

Dr Joshua Machacek
Research Fellow
Plasma Research Laboratory
Office phone
Cockcroft 5 08

The inverse swarm problem with neural networks

The traditional approach transport simulation is to measure cross sections and feed them into a code package. However, some cross sections are very difficult to both measure and calculate. The "inverse swarm problem" seeks to extract these cross sections from transport measruements such as current profiles or annihilation rates.

Dr Daniel Cocks, A/Prof. James Sullivan, Dr Joshua Machacek

Positron applications in medical physics

This is a multi-faceted project which can be adapted to students at the honours level and above. A number of possibilities exist to perform experiments directed towards improving the use of positrons in medice, mostly focussed on Positron Emission Tomography (PET).

A/Prof. James Sullivan, Professor Stephen Buckman, Dr Joshua Machacek

Positrons in plasma

Characterising plasmas is difficult. This project will explore the possibilty of probing a plasma using positrons by building a model and simulating a positron beam incident on a low-temperature plasma.

Dr Daniel Cocks, Dr Cormac Corr, Dr Joshua Machacek

Positrons and Dust Grains

Positron emitters are embedded in clouds of dust grains produced by supernova. This project will explore the transport of positrons in dust grains using Monte-Carlo techniques to improve our understanding of positron transport in an astrophysically relevant setting.

Dr Joshua Machacek, Dr Daniel Murtagh

Electron scattering in a magnetic field

A novel approach to low energy electron experiments has been developed, using strong magnetic fields to confine the electron beam. This project will further develop a new apparatus towards making important measurements of scattering cross sections.

A/Prof. James Sullivan, Dr Joshua Machacek

Benchmark positron scattering experiments

Using the atomic and molecular physics positron beam at the ANU, the student will undertake measurements of positron scattering from simple targets, providing high accuracy data to test recent theoretical calculations.

A/Prof. James Sullivan, Professor Stephen Buckman, Dr Joshua Machacek

Fragmentation of molecules by positronium

Positronium is a bound state between an electron and a positron. It is hydrogen-like with a binding energy half that of hydrogen. Positronium has been found to scatter like an electron for the same velocity. Electrons can fragment molecules by temporary attaching leading to fragmentation. This project will explore the fragmentation of molecules in positronium scattering with molecules.

Dr Joshua Machacek, A/Prof. James Sullivan, Professor Stephen Buckman

When dialing an ANU extension from outside the university:
  • (02) 612 XXXXX (within Australia)
  • +61 2 612 XXXXX (outside Australia)
Where XXXXX is the 5 digit extension number you are after.
Anti-Spam notice: The email addresses from this directory are made available to support the academic and business activities of ANU. These email addresses are not published as an invitation to receive unsolicited commercial messages or 'spam' and we do not consent to receipt of such materials. Any messages that are received which contravenes this policy is strictly prohibited, and is also a breach of the Spam Act 2003. The University reserves the right to recover all costs incurred in the event of breach of this policy.

Updated:  17 August 2017/ Responsible Officer:  Director, RSPE/ Page Contact:  Physics Webmaster