Is Antimatter Present in Cosmic Rays?

[Naty1]

In Kip Thorne's BLACK HOLES AND TIME WARPS,1993, he mentioned on page 173 that some cosmic rays particles are made of antimatter..and this was discovered by Carl Anderson at Caltech...seems like in the early 1930's...

I could not find anything about antimatter Cosmic Rays in Wikipedia...

Is this still an understanding of cosmic rays, and if so, how could antimatter survive long enough to reach earth?? Or are there some interactions hypothesized in the upper atmosphere which might create anti matter??

 

[DaveC426913]

I could not find anything about antimatter Cosmic Rays in Wikipedia...

I just found this yesterday, in response to another thread...

High-energy cosmic rays impacting Earth's atmosphere (or any other matter in the solar system) produce minute quantities of antimatter in the resulting particle jets, which are immediately annihilated by contact with nearby matter.

http://en.wikipedia.org/wiki/Antimatter#Origin_and_asymmetry

 

[Anti-Meson]

Cosmic rays comprise of primary and secondary waves.

Primary cosmic rays are mostly protons and alpha particles.

Most primary cosmic rays are the nuclei of atoms, in particular the nuclei of hydrogen atoms (protons) and helium atoms.

Secondary cosmic rays are a result of gamma rays which interact with the atmosphere to

create showers of new subatomic particles called secondary cosmic rays.

These subatomic particles are mostly

mesons, protons, neutrons, electrons, and positrons.

So the reaction is $$\gamma$$ + nucleus of atmospheric atom (hydrogen) $$\rightarrow$$ e^- + e⁺ $$\rightarrow$$ $$\gamma$$

"Cosmic Rays." 22 April 2009. HowStuffWorks.com. http://science.howstuffworks.com/cosmic-rays-info.htm 14 February 2010.

 

[DrMik]

YES! Primary cosmic rays can be antiprotons and antinuclei. Antiprotons where E>1.8GeV make up about 0.1% and antinuclei where Z $$\geq$$ 2 not more than 0.23%. So total around 0.1% to 1% maximum.
Original data from Aizu,H et al Physical Review vol116, p436 (1959) and Jain,P.L., Lohrman, E. and Teucher, M.W. Phys Rev, vol115 p636, p654 (1959). Secondary source from "The Origin of Cosmic Rays" Ginzburg and Syrovatskii, Pergamon Press 1964. May still be in print. It is an excellent scientific primer for cosmic rays (although it is a translation). Suitable for undergrad and postgrad alike.

Hope this helps

 

[Anti-Meson]

YES! Primary cosmic rays can be antiprotons and antinuclei. Antiprotons where E>1.8GeV make up about 0.1% and antinuclei where Z $$\geq$$ 2 not more than 0.23%. So total around 0.1% to 1% maximum.
Original data from Aizu,H et al Physical Review vol116, p436 (1959) and Jain,P.L., Lohrman, E. and Teucher, M.W. Phys Rev, vol115 p636, p654 (1959). Secondary source from "The Origin of Cosmic Rays" Ginzburg and Syrovatskii, Pergamon Press 1964. May still be in print. It is an excellent scientific primer for cosmic rays (although it is a translation). Suitable for undergrad and postgrad alike.

Hope this helps

• Heavy nuclei in the primary cosmic radiation at Prince Albert, Canada. I. Carbon, Nitrogen and Oxygen. Aizu, H.; Fujimoto, Y.; Hasegawa, S.; Koshiba, M.; Mito, I.; Nishimura, J.; Yokoi, K.; Schein, M. Source: Physical Review, v 116, n 2, p 436-444, 15 Oct. 1959

This article makes no reference to antimatter. Aizu et al focus on alpha particles.​

• Heavy nuclei and a particles between 7 and 100 bev/nucleon. II. fragmentations and meson production. Jain, P.L.; Lohrmann, E.; Teucher, M.W. Source: Physical Review, v 115, n 3, p 643-654, 1 Aug. 1959

Again this article makes no reference to antimatter. The authors corroborate the first article by mentioning heavy nuclei and alpha particles.​

I cannot confirm the book by Ginzburg and Syrovatskii, though based on the previous two articles it may well conclude the same.

 

[Anti-Meson]

In Kip Thorne's BLACK HOLES AND TIME WARPS,1993, he mentioned on page 173 that some cosmic rays particles are made of antimatter

Cosmic rays aren't made of antimatter. Antimatter is a product of cosmic rays interacting with the upper atmosphere.

and this was discovered by Carl Anderson at Caltech...seems like in the early 1930's...

Anderson discovered what he called a positive electron - now know as the positron, electron's antiparticle.

In measuring the energies of charged particles produced by cosmic rays some tracks have recently been found which seem to be produced by positive particles, but if so the masses of these particles must be small compared to the mass of the proton.

An extract from C.D. Anderson (1932). "The Apparent Existence of Easily Deflectable Positives". Science 76 (1967): 238.

how could antimatter survive long enough to reach earth?? Or are there some interactions hypothesized in the upper atmosphere which might create anti matter??

The latter part of this statement is the correct statement. Cosmic rays produce, albeit short lived, positrons.

 

[DaveC426913]

The latter part of this statement is the correct statement. Cosmic rays produce, albeit short lived, positrons.

As explained in post 2. In a quote from Wiki.

 

[Anti-Meson]

As explained in post 2. In a quote from Wiki.

It maybe, I am somewhat reluctant to visit wikipedia to verify this. I prefer giving Anderson's take on it.

 

[MotoH]

Most, if not all sources cited on this page, will be cited in the wikipedia article. Wikipedia is far past the old days when anyone could edit it.

 

[DrMik]

It maybe, I am somewhat reluctant to visit wikipedia to verify this. I prefer giving Anderson's take on it.

Hear Hear! I must apologise for the references given for antiparticles. The Ginzburg book is on my shelf. They gave the two references for the antiprotons and antinuclei being primary cosmic rays. I have re-read the sections and it is not exactly clear if they are the references for antiparticles or energies of general CR caught in the emulsion. The other prominent reference is:
Fradkin, M.I., Zh.exp.i.teoret. fiz., 29, 147. (1955) Soviet Phys. JETP, 2, 87 (1956).
I am amazed that you got to the first papers so fast, did you use Athens? I should renew my account and double check references I post. The Ginzburg book I have is a translation from Russian and it would be easy to lose something during translation (wouldn't be the first time).
Again I apologise.

 

[Anti-Meson]

No worries DrMik, we all get make mistakes from time to time. I don't use Athens, I use Shibboleth, which I believe is similar to Athens.

I enjoyed reading the papers, and for that I have you to thank. So thank-you.

 

[Ich]

Cosmic rays aren't made of antimatter.

Some are. There's a http://en.wikipedia.org/wiki/Payload_for_Antimatter_Matter_Exploration_and_Light-nuclei_Astrophysics" out there to analyze them, vindicating DrMik. They even found an - as of now unconfirmed - excess of antiprotons.

 

[Anti-Meson]

Some are. There's a http://en.wikipedia.org/wiki/Payload_for_Antimatter_Matter_Exploration_and_Light-nuclei_Astrophysics" out there to analyze them, vindicating DrMik. They even found an - as of now unconfirmed - excess of antiprotons.

PAMELA is there to investigate if cosmic rays have an antimatter component, not to verify that they have.

Our stand-point currently is that cosmic rays do not have an antimatter component, PAMELA might detect cosmic rays with an antimatter component, which would make us change our viewpoint.

 

[DaveC426913]

PAMELA is there to investigate if cosmic rays have an antimatter component, not to verify that they have.

Our stand-point currently is that cosmic rays do not have an antimatter component, PAMELA might detect cosmic rays with an antimatter component, which you make us change our viewpoint.

This is how I interpreted it too. The article is a bit ambiguous on the point of whether cosmic rays are presupposed to have an antimatter component, or whether that's what they're testing for.

 

[Naty1]

great input...

When I read Kip Thorne's comment and the accompanying statement that most cosmic rays come from outside our solar sysetm, but from within our galaxy, it seemed outlandish that antimatter could make it that far...

but it sounds like others think it is possible and are looking via PAMELA...good!

So it's paying off for me to read his BLACK HOLES AND TIME WARPS a third time...
It's an excellent book for a nonmathematical treatment of the subjects.

thanks.

 

[mheslep]

In Kip Thorne's BLACK HOLES AND TIME WARPS,1993, he mentioned on page 173 that some cosmic rays particles are made of antimatter..and this was discovered by Carl Anderson at Caltech...seems like in the early 1930's...

Yes, exactly. Not creates, but http://books.google.com/books?id=I3...Sw8fjCBA&cd=1#v=onepage&q=antimatter&f=false"

[...]Caltech's Robert Milligan was the world leader in the study of cosmic rays and had given them their name, and Caltech's Carl Anderson had discovered that some of the cosmic-ray particles were made of antimatter².

http://books.google.com/books?id=I3...Sw8fjCBA&cd=1#v=onepage&q=antimatter&f=false"

[...]cosmic ray. A particle of matter or antimatter that bombards the Earth from space. [...]

 

[mheslep]

Some are. There's a http://en.wikipedia.org/wiki/Payload_for_Antimatter_Matter_Exploration_and_Light-nuclei_Astrophysics"[/URL] out there to analyze them, vindicating DrMik. They even found an - as of now unconfirmed - excess of antiprotons.[/QUOTE]

[quote="Anti-Meson, post: 2581602"]PAMELA is there to investigate [I]if[/I] cosmic rays have an antimatter component, not to verify that they have.

Our stand-point currently is that cosmic rays do not have an antimatter component, PAMELA might detect cosmic rays with an antimatter component, which would make us change our viewpoint.[/QUOTE]

[quote="DaveC426913, post: 2581664"]This is how I interpreted it too. The article is a bit ambiguous on the point of whether cosmic rays are presupposed to have an antimatter component, or whether that's what they're testing for.[/QUOTE]

The [B]references[/B] are not ambiguous about the existence of anti-particles in space and the fact that they impact Earth, the ambiguity is about the amount.
[QUOTE=Nature]The satellite has found an unexpected increase in the number of high-energy positrons flitting through the Galaxy, says Bob McElrath, a theorist at CERN[/QUOTE]
[url]http://www.nature.com/news/2008/080813/full/454808b.html[/url]

[QUOTE]Recently published results from the PAMELA experiment have shown conclusive evidence for an excess of positrons at high (~ 10 - 100 GeV) energies,[/QUOTE]
[url]http://arxiv.org/abs/0810.5344[/url]

 

[Naty1]

Ok so maybe they exist.

So they have the opposite charge of their matter particle, right..and should be electromagnetically attracted since there is lots of matter or at least a lot more than antimatter...
How do they travel so far thru intestellar space and not annihhilate with matter?

What happens when one hits a satellite or space station...enough energy to do any damage.

How about the abnormally high rate of astronaut eye cataracts...any relation to antimatter or just to cosmic rays of any kind?

These things annihilate only with matter?..how about CMBR...no interaction ?

 

[sylas]

So they have the opposite charge of their matter particle, right..and should be electromagnetically attracted since there is lots of matter or at least a lot more than antimatter...
How do they travel so far thru intestellar space and not annihhilate with matter?

Antimatter particles are both positive and negative like matter particles. They don't annihilate with matter because space is "space"... empty. Cosmic rays reaching us, whether matter or anti-matter, have not bumped into anything since being emitted.

What happens when one hits a satellite or space station...enough energy to do any damage.

The annihilation energy of a cosmic ray is negligible. Energetic rays have nearly all their energy from their motion, so whether they are matter or anti-matter makes no difference to how dangerous they might be. The major danger of cosmic rays in space is not in damage to large objects like satellites, but to biological tissue or perhaps sensitive computer systems. Again, being matter or anti-matter is of little consequence.

Added in edit. Cosmic ray energies start about about 1 GeV. That is about the same as the annihilation energy of a proton, or an anti-proton. Most cosmic rays are at this low energy end of the spectrum, but they go up to many orders of magnitude larger. So I should correct myself. The annihilation energy of an anti-proton is nearly 2 GeV (include the energy of the matter particle it annihilates) which is about the same as the most common low energy cosmic rays.

The other point I didn't mention previously is to reinforce that cosmic rays are by far made up of matter, with very occasional instances of anti-matter particles.​

How about the abnormally high rate of astronaut eye cataracts...any relation to antimatter or just to cosmic rays of any kind?

I don't know if cosmic rays are significant, but if so, I don't think being matter or anti-matter would make any difference.

These things annihilate only with matter?..how about CMBR...no interaction ?

CMBR is just light. Light interacts with matter and anti-matter in the same way.

Cheers -- sylas

 

[mheslep]

Interestingly in one of the papers/references above the authors point out that cosmic ray particles must originate in our galaxy, because the interaction and energy bleed with CMBR prohibits travel over intergalactic distances.

 

[Ich]

That's true for the highest energy cosmic rays only, and they don't have to originate in our galaxy exactly, but in a galaxy not far away. Lower energy cosmic rays (below the GZK limit) are not terribly affected by the CMB.