Why ?

Others did it, so why not me !!!

The aim of this project is to build a fusion device for confining a plasma by means of magnetic and electrostatic confinement. It is not a question of being the first to produce electricity, but of designing and manufacturing a complex experimental device to explore the techniques associated with this field of physics.

The name of my project: PPPX or P3X for Projet de Piège à Plasma eXpérimental, or expérimetal plasma trap project in english

This probably requires some explanation …

 

1 / My life, my work

I am now 50 years old and have spent most of my free time building all kinds of things, robots more or less evolved, autonomous miniature submarines, various electronic assemblies. So I acquired a lot of material in electronics, computer science and mechanics. Four years ago, I decided to embark on amateur physics experiments, starting by gradually acquiring second-hand equipment, especially to have a powerful vacuum system: probes, pumps, fittings, joints. .. In parallel, I started in my corner to acquire data acquisition equipment (Labview software, USB and PCI acquisition cards …) and learn about free shared data solutions (EPICS). Very quickly caught up in the desire to use all this by a rather ambitious achievement, my first project was to build a scanning electron microscope and I threw myself on all the doc available to refresh my knowledge acquired during my schooling. .. I managed in 2015 to have a fully automated vacuum system driven by a pc and labview, but also with different secondary emission sensors built and interfaced with the pc, a perfectly functioning electron gun and a modified vacuum chamber that can receive all its peripherals. As starting to design the electronic optical part of my project (beam condensation and scanning), I realized that it presented difficulties that exceeded my skills and my material capacities, in particular to achieve the final objective of the optical column. Never mind, I started looking for a new project to take advantage of all the equipment stored in my workshop. Everything has been disassembled, cleaned and stored. In the beginning of 2017, I m back to the starting point … But an early retirement in the summer offered me on the one hand the prospect of what I missed the most, that is to say time, and on the other hand the salvation of a geographical mobility of my wife taking us back to our family home with uninterrupted access to my workshop ….

2 / First of all, achieving vacuum

Whatever the aim, the building of a small facility devoted to particle and plasma physics needs a vessel in which you will have high vacuum. This step is expensive, tedious, but exciting and indispensable. Thus, from 2013, I started designing an integrating and automated vacuum system, with the idea that it would be a key part of any future project, whatever it will be. Moreover, I take into account the fact that it will be a very long path to achieve such a project, sometimes discouraging, and that I need to sustain motivation. This step gives me the opportunity to go away from theory and hypothesis, and to come back to my workshop to make electronics, mechanics and programming. Finally, this step is rewarding, and you can realize on the forums that the search for the best vacuum is for some people  a project in itself. My first purchases: the primary pump, two oil diffusion pumps, probes and various fittings.

Based on my past experience, I decided to integrate in my project the construction of an autonomous module dedicated to high vacuum, reusable independently of the project concerned. That was the mistake (among others) that I made in my previous project: as I integrate everything in a single chassis, I can hardly reuse anything without dismantling and integrating all the elements in a new structure. I also realized that the design, build and first tests of this part was a great opportunity to take advantage of the experience accumulated over four years to solve the many problems related to vacuum: leaks, operation of diffusion pumps and turbomolecular, servocontrol of valves, interfaces of probes ….

Do not be fooled, this step stops many amateur physicists in their quest. As long as you do not succeed in building a powerful vacuum system, you cannot go further.

 3/ Back to school…

Whatever the subject, it is necessary to spend a lot of time learning and understanding. I spent three years, for my previous project, consulting all that was available on the web about electron microscopy, high vacuum, production and electron beam transport, and to translate documentation in french, to consult sites of all kinds to find a model of electronic circuit, an example of power supply for a filament …

You will never find a “fusion reactor for dummies” with handbook and assembly instructions ready to use. Even if you find a complete amateur project, well documented, you will have to modify some parts to suit to your aim, to use your own equipment…

I also wanted to share, and thus opened this site but with a time consuming challenge … I also realized from my past activities on the web that I will probably have to translate it in english, as I have to confess that  people in France really don t have any interest in amateur physics. All the mails received, questions and encouraging words for my microscopy project came from the US, Great Britain and Canada.

Since January 2017, my decision to embark on a project related to nuclear fusion has led me to go back to the web to understand the theory of fusion, magnetic confinement, the search for open documentation on existing projects, the state of amateur achievements in this field … This laborious quest will almost never end and will continue throughout the life of the project.

4 / What for – the goals?

I try here to answer to the very hard question “why?”, hoping that it allows others to lead their own thinking and to imagine their own project.

Personal goals

The first approach is to achieve a technical performance adapted to my limited means. The idea is to build a complex machine to serve as a support for real scientific experiments, and the field of fusion offers an infinite area of research of any kind and probably allows an amateur to bring a contribution, probably modest and limited, to the extraordinary effort made to date by all the industrialized countries. Dreaming doesn’t hurt but can make you go far beyond your limits … For me, the technical challenge aims to build a complex device with all its peripheral resources and maximum automation, but also to ensure the implementation on an experimental basis and publish unpretentious potential results.

And above all, please me by testing both my technical and intellectual abilities on a project that is out of the ordinary hobbies…

Dream to contribute to a scientific révolution

Since motivation will often have to be maintained, it is also necessary to have the audacity to imagine that it can be useful: contribute to the amateur effort about miniaturization in the field of fusion.

It has also been shown by several amateur and teaching projects seen on the web that the studies and experiments on machines with magnetic confinement (tokamaks, stellarators) of very small size can also lead experiments whose scientific value is exploitable. This motivation is certainly ambitious, but also generates a very attractive perspective for an amateur.

extract from an ITER document

 Small magnetic confinement fusion devices have played and continue to play an important role in fusion research. Their compactness, flexibility, low running costs and the high skills of their staff contribute to a better understanding of phenomena in a wide range of areas such as plasma containment and energy transport, stability Plasma in different magnetic configurations, plasma turbulence and its impact on local and global plasma parameters, plasma edge processes and plasma chamber-vacuum chamber interaction, scenarios with additional heating and current drive non-inductive, etc. Research on small fusion devices has created the scientific basis for extension to larger facilities. In addition, these small fusion devices offer the attractive ability to develop and test new diagnostics, materials and technologies in the most efficient way (in terms of time and cost). In addition, the experimental work on small fusion devices is very suitable for educating students, scientific activities of postgraduate students and training of staff for fusion in larger devices.

 We are still in a time in which  research on fusion devices has brought forth many ideas of configuration and implementation techniques that remain to be consolidated and experimented. As a result, the field of fusion is particularly attractive for amateurs, since there is much to do and learn.

A more reasonable goal: learn the theory of operation of fusion devices

This has always been a major goal in my various projects: learning and understanding. The studies prior to the attempt to build an experimental device with toroidal magnetic confinement make it necessary to explore very diverse fields:

  • Electromagnetism
  • Magnetohydrodynamic (MHD)
  • Plasma physics
  • Physics of electromagnetic waves and their propagation for the heating part

But also technical challenges:

  • The vacuum in physics
  • High current power supplies
  • High current electromagnets
  • Complex mechanical structures that can withstand hard constraints
  • Precise machining of forms
  • Various diagnostic means

Even if I do not complete the project, I will be at least smarter and more technically cultured !