Blog

Only showing posts tagged with 'sun' Show all blog posts

Recreating the conditions inside the sun

Introduction

Hello! My name is Asad and I’m a PhD student at the School of Mechanical, Aerospace and Civil Engineering at the University of Manchester. Within my PhD, I work in the relatively recent field of nuclear fusion. More specifically, I look at the effects of plasma damage and neutron irradiation (both known phenomenon that occur within nuclear fusion) on materials that could be used to build a potential fusion reactor.

A little bit about my background first. Before I embarked on my PhD, I completed a Master of Engineering (MEng) in Mechanical Engineering with a minor focus on Nuclear Engineering. I also did some part time study in mathematics and research projects within fluid mechanics. Of the latter, a noteworthy one is that I constructed a mathematical model of the acoustics of a banjo!


In Depth

Science has always intrigued mankind. Some of the foremost questions we have been obsessed with are the simple ones:

·  “Where did we come from?”

·  “Why are we here?”

·  “What do we do?”

No matter who you ask, you will realise that we still don’t really know the answers to these; whether we look for philosophical reasoning or scientific. We search high and low for answers. Our universe is at the centre of such research. And at the centre of our universe: the sun.

The sun can be considered a giant ball of energy. The manner in which this energy is generated is referred to as nuclear fusion. As the human species observed this, we felt the urge to exploit the process to aid our need for energy, in order to survive on a world where resources are rapidly depleting.

What exactly is nuclear fusion? The answer is a result of work done by pioneering scientists such as Ernest Rutherford, Pierre Curie and Marie Curie. We find that certain atoms of elements undergo interesting transitions. We have been able to exploit these, such as nuclear fission which is currently a dominant process to generate electricity. Within fission, we find that under the right conditions, some of the atoms will split and become smaller releasing energy in the process. Fusion is the opposite; some atoms combine and through the process release energy. It has been found that the energy released through fusion could potentially be more sustainable, cleaner, and less fraught with the risks associated with the energy generated through fission. 

Thus we are now engaged in a global technological race to be able to achieve the right conditions for fusion on earth. Thus far we have managed to recreate the conditions. However, we still haven’t managed to be able to maintain these for long enough, nor have we been able to extract power from it. We have some ideas on how to achieve both. One of the questions however is, do we have the materials to be able to do so?


This is where people like me come in. Thus far I have spoken about how this is a relatively new process mingled with a plethora of difficulties. Therefore, it will not be surprising when I say that we don’t exactly have the appropriate facilities to be able to entirely comprehend the extreme effects taking place. So how do we go about solving the problem? Some people try and use proxies, alternative approaches that in some way mimic certain effects we expect. Others try to use computational techniques and our understanding of physics to paint a picture. I’m involved in the latter. I use modelling and simulation to try and deduce what we expect. It isn’t as simple as pushing a button however. One needs to be aware of a lot of inter-related pieces of physics. Sometimes, we also find that we don’t have the computational power to actually be able to process all of these (surprising isn’t it given the progress in the field of IT).  Sometimes my job is therefore to see which processes are negligible. At other times, it is to check and draw conclusions from the results of my simulations. To name a few of the techniques I use; I use solvers for the neutron transport equation, binary collision approximation and molecular dynamics. The last considers how atoms are likely to behave. This generates some interesting perceptions of important chemical and atomic processes.

I’ll stop here. I’ll end on a note that the human race is currently engaged in very exciting things. But to see this realised; we need young, ambitious and creative minds that are keen to learn as well as try new things. 


Going Further

If you want any more information, please feel free to contact me at: asad.hussain@postgrad.manchester.ac.uk . 

To find out more about the chemical and atomic processes generated in molecular dynamics: http://lammps.sandia.gov/movies.html

A more comprehensive yet elementary guide on nuclear physics can be found at (http://hyperphysics.phy-astr.gsu.edu/hbase/nuccon.html)

Here are also some web links pertinent to what I have written: 

Culham Center for Fusion Energy: http://www.ccfe.ac.uk/introduction.aspx

Nuclear Energy Agency: http://www.oecd-nea.org/workareas/

Fusion Center for Doctoral Training: http://www.york.ac.uk/fusion-cdt/