Page 1 of 1

Fusors and Maxwell's Equations

Posted: Sat Oct 06, 2018 7:24 pm
by Nicolas Krause
I'm currently taking a standard electromagnetics physics course in my electrical engineering degree and I'm curious why the lower powered demo fusor's haven't caught on as teaching aids. The images posted here have been really helpful in visualizing the mathematical operations with Gauss' field. Surely if I wanted to approximate different Gaussian shapes, like a cylinder, or sphere I could change the grid shape in the demo fusor and obtain different looking plasma patterns. Instead of drawings on a whiteboard students would be able to physically see something in the real world.

Re: Fusors and Maxwell's Equations

Posted: Sun Oct 07, 2018 3:37 pm
by Rich Feldman
Sounds like a good idea, Nicolas.

I had the minor misfortune, in college, of being placed a year ahead in math with respect to physics. Divergence and curl of vector fields were just operations to remember and practice. Next year, in the context of electromagnetism, they immediately made sense. Became intuitive and beautiful, even, There must be people out there whose intuition holds up through quantum mechanics.

Re: Fusors and Maxwell's Equations

Posted: Mon Oct 08, 2018 5:07 am
by Richard Hull
There is an amazing opportunity in the demo fusor! I have harped on this for some years. It is in the doing and learning just how plasma work over a wide range of conditions. gas types, gas pressures, varying voltages and currents. You can "own" an understanding of the intimate and often strange and non-intuitive, (at first), actions in ionized gases. I spent two and one half years with two demo fusors reading books on ionized gases to help me understand what I was observing and why. I can't say too much about the intense pre-conditioning and learning processes with a demo fusor.

I fear far too many never take the opportunity to linger and learn with the demo device, coupled with reading in a self-directed learning and doing period well before attempting actual construction of a fusor.

Richard Hull

Re: Fusors and Maxwell's Equations

Posted: Tue Dec 18, 2018 6:43 am
by Samuel Low
Here's my take on it - it has the potential to be a GREAT educational tool, only if people allow it to be.

I got funding from my university to build one demo fusor for educational purposes. So, I wanted to use fusors to demonstrate the concepts of spherical capacitance, electrostatic fields, electromagnetic forces, in the capacity of a university senior or an IEEE member. I was a teaching assistant in the freshmore physics class and the sophomore electromagnetics class. My goal was to get "plasma and fusor-level science" down into the imagination and hands of every physics / engineering student, and I wanted to have a team or a class for these plasma making workshops.

It turned out to be an administrative nightmare for me. People were not prepared to receive the device the moment they hear the word "nuclear" or "fusion". Thoughts of explosions (or implosions) rattle in the minds of folks in the safety department or the facilities management department who do not come from very strong physics, science, or engineering backgrounds. They thought that 15,000V meant that I had to hook up 75 wall socket wires in series! Jesus! They thought that demo fusors would output neutron rays and vaporise people like the atom bomb Hiroshima or Nagasaki! When I used the term "star in a jar" to describe it (in hopes of stirring their enthusiasm), their imaginations got the science of fusing mixed up with some black-hole-generating magic that would completely destroy the campus.

In summary, communicating the science to the average student or the average school management was a downright chore and I hated it.

I spent 3 months focusing on writing safety reports and even photographing how I was going to man-handle the fusor with every step and moment, filling in hundreds of pages of risk assessments until I finally caved in and decided I was just going to build it for myself, my curiosity and my own entertainment.

I don't know how it is like from where you are, but over here in Singapore we have an immensely thick level of middle-management from bureaucratic backgrounds, even in a science or engineering institute. The level of "management", is just too much to get a fusor approved as an educational device.

That was my experience trying to bring fusors to people in real life, which is different from bringing fusors to subscribers on YouTube or the fusor forums, because demographically, the kinds of people who get attracted to such sites are naturally already inclined towards such breath-taking physics, and so the internet does the first level of filtering of the learning audience for you. In this sense I would still say that teaching and learning about fusors through the fusor forums is a lot more productive and efficient than to do it in the classroom, unfortunately by the virtue of human nature.

After all, what the mind cannot comprehend as science, it surrogates as pure black magic.

Re: Fusors and Maxwell's Equations

Posted: Tue Dec 18, 2018 5:01 pm
by Richard Hull
Samuel is right on ever single point. The old adage, "people who cannot do, teach" add to this natural failure of many teachers to ever lay a hand upon what they teach, add the litigious nature of this world to obtain money by legal means instead of working for it. Couple the foregoing with an overarching fear of virtually everything and all processes involved in the real assembly of parts and components to actually create a functioning device, and one is crippled from the get-go all the way down the line.

I advised during the construction of the VCU, Virginia Commonwealth university's, senior fusor project. (4 year effort). This interest stemmed from my presentation at an ANS meeting, (American Nuclear Society), of the amateur fusion effort in the U.S. and a followup invitation to my lab of a number of ANS members to see my working fusor. All were truly amazed as the star appeared on my large Video monitor and the 3He counter started to go nuts.

Money for the VCU fusor project came immediately due to the head of the nuclear engineering department's interest in the project. Within a few months, I was asked to oversee the results, thus far. They had a crude, but totally functional fusor system laid out schematically over two work benches. They had a full NIM bin with all the correct stuff in it and a 3He tube. They did a rather pitable amount of fusion 20kn/s, but it worked. As I left, I made a number of suggestions. One suggestion was that they make this voluntary effort a freshman to senior endeavor, much like U of W.

A year passed and at one of my ANS (American Nuclear Society) meetings at Dominion Power's meeting room, I saw the VCU department head and she indicated that once the administration heard they had a nuclear fusion system in a lab room, all effort ceased until the CHP's (pronounced "chips"), Certified Health Physics group ok'd and made recommendations on shielding, procedures, etc. Another year passes.....

I am called back to oversee their new effort. I find it is still run as a volunteer only, senior only, effort. Seniors as mere "babes in the woods" are thrust into a world they have never experienced...first hands-on plasma...first hands-on construction....first hands-on vacuum and high voltage work....etc.

As I walked in, two things struck me. No NIM bin...gone. No He3 tube...gone. I inquired where this very expensive kit was now. I got the "free look".... They had no idea what I was talking about. 3 years after I first saw proper instrumentation, it was now gone and no one knew where it got to as they never saw it in their current fractional year on the job. I asked, "how are you going to measure the neutron signature of fusion?" One student went to a drawer and pulled out a large pistol shaped device. It was a neutron counter which sported a lowest range of 0-10mrem. (worthless). There was no shielding in the room...(Did the CHPs find no hazard in the wasted year?) The system was over in the corner now, still schematically laid out with the only real change that I could see was a new, professionally welded, 6" SS fusor chamber. They had extreme issues with their super expensive 30kv, 20ma, Spellman power supply. When the plasma would strike, the supply cutout under the sharp loading. We got the current limiting shut down and ballasted the power line. The fusor now ran nicely with star mode, immediately apparent. This stunned all assembled as they gathered around with their cell and smart phones to photograph the stunning star.

The next day, when I showed up, I brought my best portable neutron counter that had a 0-1mrem range. Once running, their system barely moved the meter needle up range to about .1-.3 mrem. They were doing fusion. (Their pistol counter never budged!) I wrote out a report and e-mailed it to the head of the department with my recommendations and synopsis. I never heard a thing back.

Next thing I knew, I was invited to a senior engineering projects show for the entire college. All of the engineering departments had a show and tell. I found the fusor system neatly assembled in a roll-around cabinet on display. I fear this is the final event for the device and that it now resides in some dusty corner in a basement storage area. I may be wrong on this, but have not seen the head of the VCU nuclear engineering dept at any subsequent ANS meetings to inquire.

This is my tale of events around this effort.

Richard Hull

Re: Fusors and Maxwell's Equations

Posted: Sat Feb 16, 2019 4:17 am
by Ben_Barnett
Both very interesting accounts, Samuel and Richard.
It's very unfortunate. I think if our's ever really gets off the ground we'll be very careful... hence why when I wrote our funding proposal it was listed as a demo fusor - no neutrons allowed. I am still optimistically naive to see if we can get something going at our university, but I'll keep these accounts in mind.

Re: Fusors and Maxwell's Equations

Posted: Sat Feb 16, 2019 12:45 pm
by Dennis P Brown
A few comments that may or may not help those that desire to build a demo fusor at a school - either a student or teacher.

First and foremost, don't call a demo fusor project by that name. As soon as anyone in admin or safety googles that word, then nuclear fusion, neutrons and possibly x-rays source will appear. That will set off red flags. Call the device by what it will be at this stage: an electro-magnetic plasma demonstration device.

Next, don't use a voltage that will produce measurable x-rays; a NST is the best and safest transformer one can easily obtain at a very low cost that provides a good plasma.

Critically, call, and talk to any people that will be required to sign off - such as a safety person or department head, or principle - I have discovered that talking firsthand directly to these people so they feel they are in the loop really helps to convince them of what you are saying. Explain that it has no significant hazard at all - neither electrocution nor radiation. This will aid them in accepting the device. Provide a detail paper on these issues and why they are not issues but how this will aid students in study related subjects. Providing information like this in writing will help. Even if they barely read it, such a paper provides both proof that the issue that might be raised are addressed and makes people feel you have carefully studied these issues.

After getting approval and the device is operating for a while, approach safety or senior person that approved it previously, and ask about a possible up grade. That is, you have had great success with the device as a classroom device and now you would like to make a "demo fusor", Explain the limited upgrades you intend and its impact on safety - such as what a real fusor grade power supply addition will entail; give them details on the safety issues - electrocution hazard and possible x-ray production - then explain how you will make this safe through shielding and proper encasement of the high voltage system. Do listen to their concerns carefully and treat these with respect but provide clear explanations on how your procedures/safety measures will address their concerns. Provide a detail check list for the operation and a user list for their approval. Maybe provide a detailed paper on how and why the shielding will protect everyone and that the safety equipment will prove this - i.e. Geiger counter, any/other such device.

Hopefully, they'll give their approval. So, after approval do the work and get it operational. After they see it in operation and they test it or you show them using the appropriate testing equipment that it is safe and addresses any concerns they might still harbor, they will likely have a good appreciation of your ability to operate the device safely. Especially if they see the plasma and you explain the interesting aspects including star mode.

Finally, after a few months, ask them about what they feel would be required to do limited fusion by adding deuterium. Carefully show them the issues of neutrons, and provide all calculations (a detailed paper) on the radiation health hazards and how they are not an issue due to: low flux, shielding, and your providing an operation procedure. That proper safety of handling deuterium gas has also been addressed. Give them good reasons why neutron production is a valuable thing to do and what the students will get out of it and how this can further students interest in nuclear power. Maybe get them into STEM, etc.

While these will not guarantee anyone to get approval, such an approach might maximize your chances.