# Are any Cosmic Rays antimatter

1. Feb 14, 2010

### 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 understnading 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??

2. Feb 14, 2010

### DaveC426913

I just found this yesterday, in response to another thread...
http://en.wikipedia.org/wiki/Antimatter#Origin_and_asymmetry

3. Feb 14, 2010

### Anti-Meson

Cosmic rays comprise of primary and secondary waves.

Primary cosmic rays are mostly protons and alpha particles.
Secondary cosmic rays are a result of gamma rays which interact with the atmosphere to
These subatomic particles are mostly
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.

4. Feb 14, 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

Last edited: Feb 14, 2010
5. Feb 14, 2010

### Anti-Meson

• 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.

6. Feb 14, 2010

### Anti-Meson

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

Anderson discovered what he called a positive electron - now know as the positron, electron's antiparticle.
An extract from C.D. Anderson (1932). "The Apparent Existence of Easily Deflectable Positives". Science 76 (1967): 238.

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

7. Feb 14, 2010

### DaveC426913

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

8. Feb 14, 2010

### Anti-Meson

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

9. Feb 14, 2010

### 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.

10. Feb 15, 2010

### DrMik

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.

11. Feb 15, 2010

### 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.

12. Feb 15, 2010

### Ich

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

Last edited by a moderator: May 4, 2017
13. Feb 15, 2010

### Anti-Meson

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.

Last edited by a moderator: May 4, 2017
14. Feb 15, 2010

### DaveC426913

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.

15. Feb 16, 2010

### 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.

Last edited: Feb 16, 2010
16. Feb 16, 2010

### mheslep

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

Last edited by a moderator: Apr 24, 2017
17. Feb 16, 2010

### mheslep

Last edited by a moderator: May 4, 2017
18. Feb 21, 2010

### 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 ???

19. Feb 22, 2010

### sylas

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.

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.​

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.

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

Cheers -- sylas

Last edited: Feb 22, 2010
20. Feb 22, 2010

### 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.