tgray

Ok, more plasma tomorrow.

What did I get side tracked with? Rewiring most of the house with smart light switches (Lutron), under cabinet lighting install (Philips Hue), dropped cable TV, upped internet speed, got a new cable modem, got Youtube TV, and finally got a new amp for my stereo (DAC and old Hafler amp -> a new shiny Sonos Amp).

That last one cost me a good few hours because iTunes decided to mess with me. I have a few hi-res audio albums (96-192 kHz, and some 24 bit stuff). Sonos annoyingly doesn’t play nice with anything over 48 kHz or 16 bit. I decided to just transcode the hires stuff and replace it my iTunes library, which lives on my NAS, and keep the hires stuff separately if I wanted it. Well, iTunes decided to do some things to files at random and it took a few hours to fix. Moral of the story: standard res stuff only in iTunes.

Now it’s all sorted out. iTunes can stream to the stereo via Airplay 2, or I can play files directly with the Sonos amp pulling from the NAS (which are the same files). Next step is to load my wife’s music onto the NAS too.

tgray

Stellarators and tokamaks are very… similar. If anyone has questions about specific differences, we can discuss, but to the lay person, the difference is kind of like the difference between a gasoline and a diesel engine - they are both internal combustion engines. 🔬🔭🚀🛰

tgray

There will be no hairy spheres. If you clicked that last link, you’ll see that hairy donuts are allowed. This is the reason most fusion schemes are toroidal, i.e. shaped like a torus. The two leading contenders for magnetic fusion are the stellarator and the tokamak. 🔬🔭🚀🛰

tgray

So why not a sphere? If you think about magnetic field lines like hairs on a ball, you want to be able to comb all of the hairs so they line up with their neighbors. This topology discussion has a name: the hairy ball theorem. 🔬🔭🚀🛰

tgray

Where were we? Plasmas are hot. If we want them to do useful things, like in fusion, we have to keep them from interacting with the things we don’t want them interacting with.

Since they are charged particles, they can be ‘trapped’ on magnetic fields. 🔬🔭🚀🛰

tgray

One last plasma note for the day: the term was coined by Irving Langmuir. Read his wiki page and feel inadequate. Coincidentally, he was the inspiration for the scientist in Vonnegut’s Cat’s Cradle. I recommend The Brothers Vonnegut for those interested. 🔬🔭🚀🛰📖

tgray

So plasmas. Where do they occur?

  • Fluorescent & neon bulbs
  • Stars
  • Plasma processing
  • Fusion reactors
  • Ion engines and other electric propulsion devices
  • Arc welders (and electric arcs)
  • Plasma TVs
  • Auroras
  • Lightning (and static electricity)
  • HID bulbs

🔬🔭🚀🛰

tgray

Since plasmas are ionized, they (typically) have a lot of energy, i.e. ‘hot.’ Even low temperature (classical) plasmas are hot. Electrons in those have temperatures of 1-10 eV (electron volts). What’s an eV? 11600 Kelvin. So a ‘cold’ 1 eV plasma is 11,300 Celsius. 🔬🔭

tgray

Plasmas exhibit what is called collective behavior (think waves). They also react to electric and magnetic fields, as well as support carrying currents in them (like a conductor/wire). We will use these behaviors later.🔬🔭

tgray

A few common questions about plasma, with short answers:

  • “Is it the same as blood plasma?” No.
  • “Is it the same as plasma TVs?” Yes.
  • “Explain how a plasma globe works.” That’s complicated. So no. :)

🔬🔭

tgray

One ionization event does not make a plasma. We need a bunch. When you get a bunch, you have a quasi-neutral soup of positive (ions) and negative (electrons) charges. There are other types of plasmas (quark-gluon, non-neutral, dusty), but this is the classical one. 🔬🔭🚀🛰

tgray

As I mentioned yesterday, I’m a plasma physicist. What is a plasma? When you pump enough energy into matter, the electrons can escape from the neutral atoms. This is called ionization. The byproducts are an ion (positively charged nucleus of atom) and an electron.🔬🔭🚀🛰

tgray

I know there is one other plasma guy on micro.blog, @dcpace, so I’m going to tag him right now. He is still active in the fusion field and works at one of the most advanced tokamaks in the world, DIII-D. 🔬🔭

tgray

First, a little about myself. I am a plasma physicist. I started off studying nuclear fusion, then worked on some ‘basic plasma physics’ topics for a few years. I took a brief detour while I worked as a valve designer before I ended up working on electric propulsion. 🔬🔭🚀🛰

tgray

I’m purposefully breaking it up across many days; I don’t want it to be a giant sprawling blog post that no one will ever read. I’ll try to do a few meaningful bits every day, but no promises. 🔬🔭🚀🛰

tgray

I have a little free time on my hands right now, so I thought it would be a good idea to flesh out the science and space topics here. This will be a meandering discussion. Please feel free to stop me and ask questions. Or to redirect the conversation.🔬🔭🚀🛰