The case of the relativistic particles solved with NASA missions

May 29, 2018 by Mara Johnson-Groh, NASA's Goddard Space Flight Center

Encircling Earth are two enormous rings—called the Van Allen radiation belts—of highly energized ions and electrons. Various processes can accelerate these particles to relativistic speeds, which endanger spacecraft unlucky enough to enter these giant bands of damaging radiation. Scientists had previously identified certain factors that might cause particles in the belts to become highly energized, but they had not known which cause dominates.

Now, with new research from NASA's Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms—THEMIS—missions, published in Geophysical Research Letters, the verdict is in. The main culprit is a process known as local acceleration, caused by electromagnetic waves called . Named after their characteristic rising tones, reminiscent of chirping birds, chorus waves speed up the particles pushing them along like a steady hand repeatedly pushing a swing. This process wasn't a widely accepted theory before the Van Allen Probes mission.

Establishing the main cause of the radiation belt enhancements provides key information for models that forecast space weather—and thus protect our technology in space.

"We've had studies in the past that look at individual events, so we knew local acceleration was going to be important for some of the events, but I think it was a surprise just how important local acceleration was," said Alex Boyd, lead author and researcher at New Mexico Consortium, Los Alamos, New Mexico. "The results finally address this main controversy we've been having about the radiation belts for a number of years."

In a background magnetic field, represented by the cyan arrows, two electrons are propagating to the right, executing identical gyromotion. A circularly polarized electromagnetic wave approaches the upper electron from the left. Credit: NASA

There are two main causes of particle energization in the Van Allen belts: radial diffusion and local acceleration. Radial diffusion, which often occurs during solar storms—giant influxes of particles, energy and magnetic fields from the Sun, which can alter our space environment—slowly and repeatedly nudges particles closer to Earth, where they gain energy from the magnetic fields they encounter. Many scientists had long thought this was the primary, or even only, cause of energization.

However, early on in its mission, the Van Allen Probes showed that local acceleration, which is caused by particles interacting with waves of fluctuating electric and magnetic fields can also provide energy to the particles. The new research, which looked at nearly a hundred events over almost five years, shows that these wave-particle interactions are responsible for energizing particles around Earth 87 percent of the time.

Chorus waves as heard by the EMFISIS instrument aboard NASA's Van Allen Probes as it passed around Earth. Credit: NASA/University of Iowa

The scientists knew that local acceleration was at work because they observed mountains of energetic growing in one place, as the local acceleration mechanism predicts, rather than sliding in Earthwards as diffusion would.

That's a large percentage for a process that wasn't perceived as a strong candidate even five years ago. "Radial diffusion is definitely important for the radiation belts, but wave-particle interactions are much more important than we realized," said Geoff Reeves, co-author at the New Mexico Consortium.

Explore further: FIREBIRD II and NASA mission locate whistling space electrons' origins

More information: What Causes Radiation Belt Enhancements: A Survey of the Van Allen Probes Era, Geophysical Research Letters (2018). doi.org/10.1029/2018GL077699 , agupubs.onlinelibrary.wiley.co … 10.1029/2018GL077699

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cantdrive85
1.4 / 5 (8) May 29, 2018
And not a mention of double layers.

"Students using astrophysical textbooks remain essentially ignorant of even the existence of plasma concepts, despite the fact that some of them have been known for half a century. The conclusion is that astrophysics is too important to be left in the hands of astrophysicists who have gotten their main knowledge from these textbooks. Earthbound and space telescope data must be treated by scientists who are familiar with laboratory and magnetospheric physics and circuit theory, and of course with modern plasma theory." Alfvén

Their "chorus waves" are more likely double layers per their own description, but alas they are plasma ignoramuses.
691Boat
4.6 / 5 (12) May 29, 2018
And not a mention of double layers.

Pretty sure that is because there are no double layers involved. Unless you have evidence that these (or any) probes found your ginormous DC current powering the solar system, you have nothing but bad guesses with absolutely no actual backing.
jonesdave
3.4 / 5 (12) May 29, 2018
And not a mention of double layers.

"Students using astrophysical textbooks remain essentially ignorant of even the existence of plasma concepts, despite the fact that some of them have been known for half a century. The conclusion is that astrophysics is too important to be left in the hands of astrophysicists who have gotten their main knowledge from these textbooks. Earthbound and space telescope data must be treated by scientists who are familiar with laboratory and magnetospheric physics and circuit theory, and of course with modern plasma theory." Alfvén

Their "chorus waves" are more likely double layers per their own description, but alas they are plasma ignoramuses.


Lol. What an eejit.
jonesdave
3.9 / 5 (11) May 29, 2018
So. let's sum up the idiot Canttthink's beliefs, shall we? Earth used to orbit Saturn. Correct, woo boy? Venus came hurtling out of Jupiter? Correct, woo boy? Laws of physics were broken as this idiotic woo describes how Venus passed by Earth and Mars. Correct, woo boy? We are supposed to take this seriously, because of what? Woo boy?
Ever done a science degree, woo boy? No, thought not. What about the idiots that you follow? Thornhill? Got a BSc, didn't he? I've got two. Talbott? Complete wanker. Eh? Scott? EE, isn't he?
Oh dear, nobody qualified. Eh?
Wankers.
Whydening Gyre
5 / 5 (6) May 29, 2018
And not a mention of double layers.

Pretty sure that is because there are no double layers involved. Unless you have evidence that these (or any) probes found your ginormous DC current powering the solar system, you have nothing but bad guesses with absolutely no actual backing.

Sorry, 691. Hit the 4 on my way to 5...
CD,
what would prevent 2 sheets of opposite charge from coming together? An insulator.
What and where is that insulator?
cantdrive85
1 / 5 (4) May 29, 2018
Pretty sure that is because there are no double layers involved. Unless you have evidence...

Pretty sure you're a plasma ignoramus too.

https://www.ncbi....4476280/
@jonesdumb
So. let's sum up the idiot Canttthink's beliefs

Let's change the subject again...
what would prevent 2 sheets of opposite charge from coming together? An insulator.

The existence of DL's in plasmas was established back in the 1920's, it's why Langmuir got his Nobel prize. See above, DL's are ubiquitous in plasmas.
Mimath224
5 / 5 (2) May 29, 2018
@Whydening Gyre I may be wrong of course but I thought double layers could be produced in plasma as long as external conditions were supplying electron acceleration. I remember reading somewhere, DL could be produced in aurora, which I think you are suggesting with your question (in a general way and not specifically in aurora). Would electrons be accelerated in the the VA belts due to the Solar Wind?
cantdrive85
1 / 5 (4) May 30, 2018
I may be wrong of course but I thought double layers could be produced in plasma as long as external conditions were supplying electron acceleration.

Yep, you're wrong. The electric fields in the double layers accelerate the electrons/ions.
691Boat
5 / 5 (5) May 30, 2018
I may be wrong of course but I thought double layers could be produced in plasma as long as external conditions were supplying electron acceleration.

Yep, you're wrong. The electric fields in the double layers accelerate the electrons/ions.

hahaha! I love it. The electric fields in the double layers provide the acceleration to the electrons to produce the double layers. amazing. I love when something causes itself or results in the generation or amplification of itself. really cool science ya got there.
cantdrive85
1 / 5 (3) May 30, 2018
The electric fields in the double layers provide the acceleration to the electrons to produce the double layers. amazing

What's amazing is your stupidity. The double layers arise when there are two plasmas with different properties adjacent to one another. The sheath, boundary, double layer, whatever you want to call it naturally arises to protect the two plasmas from one another. Just as a cell wall protects the cell from its surroundings, so too will a plasma create a barrier to protect it from its surroundings. However, the boundary acts as a part of the circuit in the energy transfer process. Within that boundary is where the e-fields arise which can accelerate the particles.
But you're so well informed of EM/plasma processes you already knew that, correct?
691Boat
5 / 5 (4) May 30, 2018
@CD85:
What causes two plasma in space from the same source to have different properties to allow the formation of said double layer? Are these different plasmas still quasi neutral? Are these double layers acting as more of an accelerating beam or a capacitor? Seems that for true double layers, there needs to be sufficient charge difference between the plasmas. How do these 2 neutral plasmas with different charge ratios get formed when they come from the same source (i.e. our Sun)?
RealityCheck
2 / 5 (4) May 30, 2018
@jonesdave, @691Boat, @cantdrive et al.

Please go read about improving detection, measurement and insights now happening re 'plasma-immersed-surfaces' charge-interaction phenomena:

https://phys.org/...sma.html

Good luck all. :)
cantdrive85
1 / 5 (3) May 30, 2018
What causes two plasma in space from the same source to have different properties to allow the formation of said double layer?

You're making assumptions, wrong assumptions. The article above is discussing Van Allen belt measurements, these are both solar wind and Earth plasmas interacting.

Regardless, the filamentary aspect of plasmas proves beyond a shadow of a doubt this idea of this imagined quasi-neutral cloud of plasma doesn't exist. Sure, there are appox. equal amounts of ions and electrons in a given volume, this doesn't say there isn't charge separation within that volume. If there is charge separation, there will be surface layers between the two plasmas.
jonesdave
2.6 / 5 (5) May 31, 2018

You're making assumptions, wrong assumptions. The article above is discussing Van Allen belt measurements, these are both solar wind and Earth plasmas interacting.

Regardless, the filamentary aspect of plasmas proves beyond a shadow of a doubt this idea of this imagined quasi-neutral cloud of plasma doesn't exist. Sure, there are appox. equal amounts of ions and electrons in a given volume, this doesn't say there isn't charge separation within that volume. If there is charge separation, there will be surface layers between the two plasmas.


Given that THEMIS and the VA probes have flown through these regions, it should be trivial to look at the data and see these DLs, yes? So where are they? And who is saying that they exist? Just an EU crackpot as far as I can see. Ergo, not worth listening to.
cantdrive85
1 / 5 (3) May 31, 2018
Given that THEMIS and the VA probes have flown through these regions, it should be trivial to look at the data and see these DLs, yes?

jonesdumb obviously prefers willful ignorance to real knowledge;

https://www.ncbi....4476280/

I guess Mozer is just an EU crackpot...
jonesdave
2.6 / 5 (5) May 31, 2018
Given that THEMIS and the VA probes have flown through these regions, it should be trivial to look at the data and see these DLs, yes?

jonesdumb obviously prefers willful ignorance to real knowledge;

https://www.ncbi....4476280/

I guess Mozer is just an EU crackpot...


No, he isn't. I have often referenced his work on here re magnetic reconnection. He has co-authored with Falthammar. Perhaps you should read some of his stuff, instead of just cherry picking things that you think have something to do with EU woo. I suspect these two papers are looking at two different things, but will need to read them to be sure. Something EU wooists never do.
cantdrive85
1 / 5 (2) May 31, 2018
I suspect these two papers are looking at two different things,

Actually, you said;
Given that THEMIS and the VA probes have flown through these regions, it should be trivial to look at the data and see these DLs, yes?

And I provided the observations of the double layes, which you still seem to want to ignore. There is some of that woo you said is impossible, but as usual you contort, confuse, and change the topic.
You calling Mozer a crackpot, EU wooist is pretty funny. He could be not including the pseudoscientific MRx nonsense. LOL!
jonesdave
3 / 5 (6) May 31, 2018
You calling Mozer a crackpot, EU wooist is pretty funny.


I didn't, you idiot. Read what I wrote. Which part of "No, he isn't", are you having trouble understanding?
jonesdave
3 / 5 (6) May 31, 2018
He could be not including the pseudoscientific MRx nonsense. LOL!


No, he really couldn't. For a kick off he is actually scientifically qualified in his subject area. Secondly, I very much doubt he believes that Earth used to orbit Saturn, or that Venus came shooting out of Jupiter, among other crackpot nonsense. And what is EU about DLs? They were measuring those long before the idiot Thornhill got his cult together.
cantdrive85
1 / 5 (3) May 31, 2018
@jonesdumb
And who is saying that they (DL"s) exist? Just an EU crackpot as far as I can see.

'Megavolt parallel potentials arising from double-layer streams in the Earth's outer radiation belt.'
Mozer FS, et al. Phys Rev Lett. 2013.

Mozer says there are double layers, ergo you claim he is EU crackpot.
jonesdave
3 / 5 (6) May 31, 2018
@jonesdumb
And who is saying that they (DL"s) exist? Just an EU crackpot as far as I can see.

'Megavolt parallel potentials arising from double-layer streams in the Earth's outer radiation belt.'
Mozer FS, et al. Phys Rev Lett. 2013.

Mozer says there are double layers, ergo you claim he is EU crackpot.


I was talking about the paper that this article refers to. Not one that you have decided to introduce after the fact, because this one doesn't happen to mention DLs. You are unqualified to comment on either paper. Nor is anyone else associated with EU nonsense. If you are so sure of yourself, why not write a reply to this paper in the same scientific literature? Otherwise, your comments are pointless and worthless. Just another crank on a comments section.
cantdrive85
1 / 5 (3) May 31, 2018
Your weak-minded tactics are amusing jonesdumb. The only thing you and your faerie tale pseudoscience have to offer real science is a lesson as to how easy it is to present pop-sci-fi bullshit as legitimate science in this day and age.
jonesdave
2.6 / 5 (5) May 31, 2018
Your weak-minded tactics are amusing jonesdumb. The only thing you and your faerie tale pseudoscience have to offer real science is a lesson as to how easy it is to present pop-sci-fi bullshit as legitimate science in this day and age.


Says an idiot that believes in EU woo! Tell us, when was Earth orbiting Saturn? Irony much? Lol.

P.S. What is a collisionless plasma again? Back to the mythology, woo boy.
cantdrive85
1 / 5 (1) May 31, 2018
Change the subject much jonesdumb?
jonesdave
3.3 / 5 (7) May 31, 2018
Change the subject much jonesdumb?


Change it from what? The fact that you do not understand plasma physics worth a damn, and that nobody within your cult is qualified to understand it?

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