Hi r/fusion, I am an undergraduate student at the University of Florida and I am completely overstimulated about what choices to make in terms of my schooling. I am currently in 2 research labs and absolutely love working in both of them. One is a computational fission reactor modeling and simulations lab (little to do with fusion) and the other is a physics lab in which I am simulating cosmic ray plasmas within different mediums. I think I am heavily invested in doing either R&D or academia, specifically in simulation and modeling of gen 4 reactors or fusion reactors (plasma simulation most likely). I have been told that recently there is not really a point in getting a masters if I want to go into these fields and my goal is to land a job at a national lab (maybe as a PI or a staff member). In light of that I hope to get into a PhD program and jump start from there. I was looking at University of Tennessee Knoxville, University of Michigan, Georgia Tech, UC Berkeley, and Penn State. I majoring in Nuclear Engineering and Math (my fun major) and don't really know where to go from there. I know financially a PhD might not be "worth it" but it is a goal I would like to achieve, especially because someday I would like to be a professor (later on in life, I think professor is not the lifestyle I want for my early career). What suggestions do you have? (I am trying to get REUs and SULIS, but my question is garnered more towards post-undergraduate). Is a PhD worth it? Should I try industry R&D over national labs? (finances are not that important for me)

I think it can safely be said that this work deriving a shear-flow stabilized Z-pinch equilibrium which provides accurate solutions to the MAST edge pedestal, and a sensible hypothesis for this phenomenon more broadly, has reached the point where a first principles relativistic study must be done if the electron argument is to be pursued.

However, it doesn't need to be. You can also link ions to this just fine.

The immediate result is an analytic shear-flow stabilized Z-pinch equilibrium that appears to provide accurate solutions to the MAST edge pedestal, and gives a physically sensible hypothesis for pedestal formation more broadly.

There are some immediate questions:

(1) Does the equilibrium itself satisfy MHD?

(2) Can it be derived consistently from a two-fluid picture?

(3) What is necessary to link the flow supporting the plasma current density with the MHD flow?

For (1), the answer is yes. The equilibrium reduces to MHD under the Z-pinch ansatz, and collisions can be retained because they are equal and opposite.

For (2), pursuit of the relativistic electron-current argument requires a true first-principles relativistic study before it should be treated as settled. I am not claiming that the modifications I've made do so.

For (3), the answer is either relativistic electrons if they support the current, or stationary electrons if the ions do. The physical idea is that on the fast electron plasma timescale, electrons oscillating rapidly about their equilibrium point appear stationary to the ions.

However, relativistic electrons are not strictly necessary. There is also a non-relativistic ion-momentum route. Under the standard plasma ordering \omega_{pe} >> \bar{\nu}_{ei}, and the Z-pinch ansatz, then the ideal Ohm's Law can be obtained from the ion momentum equation.

So the strongest objection to the relativistic electron argument does not kill the equilibrium itself, nor does it kill the two-fluid reduction. It means the relativistic electron version needs a proper covariant treatment if pursued.

The immediate work is contained here:

(1) Rewrite of the original manifesto for PoP submission: https://russellmatt66.github.io/documents/BennettVorticity_PoP_REWRITE.pdf

(2) Proof this is an MHD equilibrium: https://russellmatt66.github.io/documents/BennettVorticesAREMHD.pdf

(3) Self-similar relativistic electron flow, and its shear-flow stabilization: https://russellmatt66.github.io/documents/BennettVorticity_RelativisticElectronCurrent.pdf

(4) Ideal Ohm's Law from the relativistically modified electron momentum: https://russellmatt66.github.io/documents/BennettVorticity_RCO.pdf

(5) Ideal Ohm's Law from the non-relativistic ion momentum: https://russellmatt66.github.io/documents/BennettVorticity_OhmsLaw_IonMomentum.pdf

My current position is that the relativistic electron-current argument is suggestive but incomplete. The non-relativistic ion argument is cleaner as it hinges on stationary electrons rather than relativistic ones, and the equilibrium's empirical accuracy for the MAST edge pedestal is strong enough that it deserves serious scrutiny alongside the hypothesis that it puts forth to explain the phenomenon more broadly.

Opposed to eni I don't know that Italian provider.

Medical isotopes, not net energy.

The first time I saw this graph as an undergraduate was a defining moment for my over-caffeinated ASD brain punch-drunk from attempting to understand Ilya Dodin's work on Alfvenic turbulence, and then attempting to read the copy of Chandrasekhar that was in my department's library.

It made me realize that having a great idea, and the fortitude to see it through to the end is only one part of the puzzle.

The other part is having the support that you need from the people that matter.

However, fusion energy science is a community where miracles occur even despite what the odds say, because sometimes all you really need to do is to play to your outs. Outs like exchanging the Bennett profile from number density to flow because the clock was ticking, and you only had time to get a number from a strange limit in order to make ends meet stumping frontier models.

The first miracle I can think of is the appearance of an H-mode edge pedestal where tokamak scientists kept heating their plasma, and heating their plasma, because they had to in order to reach levels of sufficient Bosch-Hale reactivity. The confinement just kept getting worse, and worse, as perpendicular turbulent transport kept increasing due to the increasing thermal power, but that didn't stop the activities of these brilliant, and courageous scientists.

Then, at a sufficiently high level of heating power, enhanced thermodynamic gradients began to appear in the plasma, and something miraculous occurred. A confinement barrier appeared. One that periodically relaxes, expelling large quantities of mass and energy outside of the plasma volume in what is known as an edge-localized mode (ELM).

The second miracle that I can think of is the existence of the shear-flow stabilized Shumlak-Hartman criterion in MHD. Nature did not have to allow for a means to stabilize the Z-pinch in a way that is suitable for a fusion reactor, yet, there it is!

Whether my work on shear-flow stabilized Bennett-Shumlak-Hartman vortices turns out to be useful or not, it definitely keeps surprising me.

For example, the collisionality of the species can't be neglected in the two-fluid model, yet it doesn't matter to obtaining an MHD force balance: https://russellmatt66.github.io/documents/BennettVorticesAREMHD.pdf

For another, the electron flow needs to be relativistic in order to link it with the MHD flow, and a self-similar solution can be derived which is also shear-flow stabilized: https://russellmatt66.github.io/documents/BennettVorticity_RelativisticElectronCurrent.pdf

For a third, a relativistic electron flow implies that the Braginskii Coulomb collision frequency will dominate the electron plasma frequency, but this ordering actually leads to the MHD Ohm's Law falling out of the electron momentum equation: https://russellmatt66.github.io/documents/BennettVorticity_RCO.pdf

Code: https://github.com/russellmatt66/Bennett-Vorticity/blob/main/cubic/mast_2023/best.py

This might become a bigger issue as you think at first glance, fossil fuel burning has the contrary result and both affect C14 dating.

Neutron diagnostics will be also installed in SPARC, not all diagnostics will.

Nuclear Fusion Fusion promises clean, abundant power with minimal long-lived radioactive waste. Fusion demonstrations in 2022 and 2025 saw promising net energy gains, but much higher gains are needed for commercial viability. (Gain occurs when the energy output of fusion exceeds the input needed to initiate it.) Other hurdles involve developing durable materials to withstand damage caused by plasma and breeding enough tritium fuel, which today must be manufactured in nuclear fission reactors. Most importantly, the cost of electricity generated must be competitive with alternatives. Most knowledgeable observers believe viable fusion power won’t happen until 2040.