Pinched plasma inside a neutral beam injector

In summary, the conversation discusses the possibility of using a similar concept to the Zap Energies sheared flow pinch reactor in a neutral beam injector. The idea is to first compress and heat the plasma inside the NBI using a pinch, then heat it using microwaves, accelerate it, and neutralize it. However, it is pointed out that this may not be efficient as the NBI machine is already designed to add reactants and energy to the plasma. Additionally, compressing bare ions is more difficult than compressing a neutral plasma. RF heating is also mentioned as a method used to directly heat the tokamak plasma.
  • #1
Andrewtv848
17
3
TL;DR Summary
I was wondering if you could use a Z pinch as well as microwaves to heat a plasma inside a neutral beam injector?
Let me start this off with saying I am just a uneducated idiot, But after reading about Zap Energies sheared flow pinch reactor I was wondering if you could use a similar concept in a neutral beam injector? Like could you first compress and heat the plasma inside of a NBI using a pinch, then heat it using microwaves, accelerate it and neutralize it.
Its just a rough idea and I probably over looked something completely obvious but it would be nagging at me if I didn't ask.
thank you for your time,
Andrew
 
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  • #2
Did you look at the basic articles with respect to this topic?
https://en.wikipedia.org/wiki/Neutral-beam_injection

Neutral beam injection actually accelerates the ions that it uses after it strips electrons from ions before the acceleration phase. Then once the ions are accelerated it reintroduces electrons so that the fast ions could enter the plasma without being deflected , because the charge on both protons and electrons is the same strength but the mass differs by alot, so it is essential to accelerate the ions instead of electrons.
The gained kinetic energy then adds to the plasma energy by interactions.I don't believe your idea is meaningful because the NBI machine in of itself is a way to add reactants to the tokamak plasma while also adding energy to it.
+ to compress bare ions is much harder than to compress a plasma that is neutral also having electrons present because bare ions have higher electrostatic repulsion than if they are within a plasma that also has electrons.

On the microwaves part I'm not sure but I would believe that it wouldn't be efficient because the idea within a neutral beam injector is to cause the ion beam to gain linear momentum so that after recombination with electrons they can fly into the fusion plasma much like a car accelerates within the accelerating lane to flow within the highway traffic , only unlike a car on a highway the accelerated ions then interact with existing ones within the fusion plasma and share their energy.
RF heating is done directly to the tokamak plasma with antennas located on the inner sides of the tokamak chamber.
 

FAQ: Pinched plasma inside a neutral beam injector

What is a neutral beam injector?

A neutral beam injector is a device used in plasma physics and fusion research to introduce neutral particles into a plasma. It typically generates a high-energy beam of neutral atoms that can penetrate the plasma without being affected by electromagnetic fields, allowing for heating and current drive in fusion reactors.

What does "pinched plasma" refer to?

Pinched plasma refers to a state of plasma where magnetic or electric fields compress the plasma, leading to increased density and temperature. This phenomenon can enhance the confinement of plasma, making it more stable and efficient for fusion reactions.

How does pinching occur in a neutral beam injector?

Pinching in a neutral beam injector can occur when the injected neutral beam interacts with the plasma, leading to local increases in density and temperature. The neutral atoms can ionize upon entering the plasma, contributing to the overall plasma pressure and creating conditions conducive to pinching.

What are the benefits of using pinched plasma in fusion research?

The use of pinched plasma in fusion research can improve confinement times and increase the likelihood of achieving the necessary conditions for fusion. By maintaining higher temperatures and densities, researchers can enhance the efficiency of energy production in fusion reactors.

What challenges are associated with pinched plasma in neutral beam injectors?

Challenges associated with pinched plasma include maintaining stability and controlling the dynamics of the plasma during the pinching process. Instabilities can lead to loss of confinement and energy, and managing the balance between heating and confinement is crucial for successful operation in fusion experiments.

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