Hello, reader! We’re back with how fusion reactors work here on Earth to replicate the nuclear fusion that powers our Sun!
Wait, Carlos, I’m a new reader here, so what do I do?
Don’t worry, I got you covered! Here is our previous “Nano-Story” on what is Fusion!
100 Nano-Stories: What is Fusion?
Episode #5: Fundamental Concepts of Fusion Energy!
Gee, thank you, Carlos! You’re a real life-saver!
Thank you, reader! Now, today’s topic is…
Methods For Fusion
Today, we have two main methods of achieving fusion: inertial confinement and magnetic confinement.
Inertial Confinement is using hydrogen as our fuel, but instead of plasma, we are using hydrogen from a pellet that is composed of deuterium-tritium. This hydrogen pellet is being compressed with a lot of density and temperature. The fusion power happens before this pellet explodes; which is very little time.
Hmm… doesn’t sound that good, Carlos.
Hold on! Don’t jump to conclusions yet!
Fortunately or unfortunately, we only have about a few milliseconds before the hydrogen pellet explodes! But during this process, lasers are aimed at that pellet to heat, pressurize, and compress it to fuse into helium and release energy. The pellet radius must reach over 3 grams per square cm for the pellet to burn in a lesser time than it takes for disassembly.
The problem with this form of fusion energy is that it takes more energy for the lasers to use more energy than what we get in return. The lasers are too powerful, and they require a lot of energy, and I mean it.
Hmmm… then what about Magnetic Confinement? Is that better than Inertial Confinement?
Magnetic confinement is heating & squeezing hydrogen plasma via electric and magnetic fields.
But why both electric & magnetic fields, Carlos?
Hydrogen gas is heated by heat, microwaves, and more to eventually create the soup of ionized charged particles we call plasma. This is when the plasma will become compressed via magnets to begin the fusion process.
Oh! So that photo you showed us in the beginning, is that what people would normally use for fusion?
Actually, we normally use a toroid as our magnet to generate fusion! A toroid looks like your breakfast bagel or doughnut, you can pick whichever one you prefer!
Sounds interesting! Is there more behind magnetic confinement?
Yup! Let’s briefly talk about…
Huh? Is this gibber-ish or something?
A Tokamak is a bagel-shaped chamber that contains large magnets that are coiled around the tokamak. The reason for these magnetic coils is because they can confine plasma particles to allow the plasma to achieve the conditions necessary for fusion.
Wow! So this is how people achieve the nuclear fusion you were talking about! Can I see how big these coils are?
Woah! I’m interested! Tell me more about it!
The fusion reactor begins by heating deuterium and tritium to produce the hot plasma. Once the plasma is made, the plasma will be squeezed so the fusion can occur, and this reaction causes the lithium blankets surrounding the plasma chamber to absorb the neutrons, which produces more tritium fuel and heat.
Carlos, but why do we need heat?
This heat gets transferred to a heat exchanger to create steam, which drives turbines to create electricity, reader!
Cool! So what’s the problem with them?
The problem with tokamaks is that the plasma can fluctuate without warning. Scientists haven’t figured out how to get the reaction to self-sustain.
Awww.. so, no nuclear fusion then?
Calm down, reader! There is always hope for fusion energy to occur!
- Fusion Energy is what powers the Stars in the Universe.
- Fusion occurs when two particles merge to form nuclei & release energy.
- Unfortunately, we need a lot of energy to achieve nuclear fusion
- Fusion is possible via nuclear reactors!
- The two forms of Nuclear Fusion Reactors are Inertial Confinement and Magnetic Confinement to achieve high temperatures.
- If we can achieve Fusion, Fusion would be abundant, safe, environmentally friendly, affordable, and would be able to be produced on demand!
- Unfortunately, progress on fusion energy has not been where we would like it to be: there are technical, environmental, and political hindrances.
- Plasma is hard to sustain and hard to maintain high temperatures about 100 million degrees Celsius!
- Because progress on fusion is slow, it may not be able to mitigate the effects of climate change.
- Cost and Energy Output! It costs a lot for the tokamak and the pieces that make nuclear fusion, but our output is significantly less than what we add for our input of energy!
© 2021 by Carlos Manuel Jarquin Sanchez. All Rights Reserved.