Radiation protection of astronauts in human missions to Mars: simulation and reality

Associate Professor: Susanna Guatelli
University of Wollongong
This special colloquium will be held at 2 PM, 27th May, in  Parnell building (07), Room #222

Abstract: Human missions to Mars have been identified as a main goal of human exploration by the International Space Exploration Coordination Group in 2013. The roadmap to the human exploration of Mars started with the International Space Station mission about twenty years ago and is envisaged to continue with a human outpost on the Moon and finally with a mission to Mars within the next twenty years.  A human mission to Mars would expose astronauts to serious health hazards, including acute and late risks caused by exposure to cosmic radiation, eventually leading to cancer and death. The design of shielding solutions and of powerful and accurate radiation monitoring systems are subjects of research to facilitate the human exploration of the Solar System. However, the testing of proposed novel technologies is limited on Earth as there are no accelerator facilities capable to reproduce the complex cosmic radiation field the astronauts would encounter in space. In the past fifteen years, Monte Carlo simulations, capable to describe cosmic radiation interactions in space mission habitats and in astronauts, demonstrated to be an extremely useful tool for radiation protection studies of astronauts. This seminar will begin with a description of the health hazards in astronauts caused by cosmic radiation and of Monte Carlo simulations for space exploration. The speaker will then illustrate her research in this field aimed to develop simulation tools to improve the prediction of health hazards in astronauts.

Bottom-up design of materials using organic building blocks

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Prof. Jennifer MacLeod
Queensland University of Technology

Abstract: One of the goals of nanoscience is achieving precise control over the structure and function of nanoscale architectures at surfaces. Bottom-up approaches using molecular building blocks present a flexible and intuitive approach to this challenge. Combining the Lego-like modularity of molecules with the epitaxial and reactive influences of surfaces creates a range of opportunities to build exciting new nanoarchitectures, which potentially have interesting and/or useful electronic properties.

I will describe two approaches to the fabrication of 1D and 2D organic materials. The first approach is based on self-assembly, which is spontaneous organisation of building blocks via non-covalent interactions. Self-assembled films can be highly-ordered and relevant to, e.g., thin-film organic semiconducting devices. The second approach addresses this point. The second approach involves covalently bonding organic building blocks on a surface, which can create robust materials with tailored electronic properties, I will discuss our recent work in studying the reactions of halogenated and carboxylated molecules at metal surfaces, where we have been focussing on understanding the effect of heteroatoms in the coupling reaction and the subsequent formation of oligomeric and polymeric structures. These studies draw on a combination of scanning tunnelling microscopy, photoelectron spectroscopy and near-edge x-ray absorption fine structure to gain a well-rounded insight into the processes.

The end goal of this work is to establish an understanding of how structure and function are related in these materials. Measuring the electronic properties of organic materials can be challenging, as not many methods offer a way to directly characterise their unoccupied electronic structure. I will provide an overview in our recent work in developing an inverse photoelectron spectrometer optimised for use on organic materials. This instrument, in combination with ultraviolet photoelectron spectrometry, allows us to measure all relevant energy levels in our organic materials.

Superfluids of light

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Prof. David Snoke
University of Pittsburgh, USA

Abstract: It is possible to engineer the properties of photons in an optical medium to have an effective mass and repulsive interactions, so that they act like a gas of atoms. These “renormalized photons” are called polaritons. In the past decade, several experiments have demonstrated many of the canonical effects of Bose-Einstein condensation and superfluidity of polaritons. In this talk I will review some of this past work and present recent results with polaritons that have very long lifetime, including movies of equilibration and damped oscillations of a condensate.

Exploring the Precision Frontier with Belle II

 

Prof. Markus Prim
Karlsruhe Institute of Technology
& KEK (High energy accelerator Research organization, Tsukuba, Japan)
This colloquium will be held at 11 am, 14th February 2020, in  Parnell building(07), Room #222
Abstract:
The Belle II experiment is a next-generation B-Factory located at the SuperKEKB electron-positron collider facility in Tsukuba, Japan. The experiment started to record collisions in 2018 and aims to collect a data sample of 50/ab in the coming years. The large anticipated collision data set will allow for precision tests to challenge the Standard Model of particle physics and search for signs of new physics processes and phenomena beyond the direct production threshold of the Large Hadron Collider. This talk will present the current status of Belle II and discuss the ongoing effort to search for signs of new physics at the precision frontier.