Timeline for Does cosmic radiation have a predominant 'direction of origin'?
Current License: CC BY-SA 4.0
10 events
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| May 25, 2021 at 8:49 | comment | added | user21103 | @uhoh right, but they haven't travelled through a field with a well-defined single orientation: they have travelled through many light years of fields with many orientations. However I'll take the sentence beginning with 'observations'. | |
| May 24, 2021 at 18:47 | comment | added | uhoh | An oriented field will not scramble their directions, it will not make them random or isotropic. Instead you may see quite a substantial difference in the flux per unit solid angle perpendicular to the field lines vs parallel to it. It could be a substantial anisotropy, and possibly the perpendicular flux per unit solid angle will be larger perpendicular to it which means you may have two minima along the direction of the field lines. It's a complicated problem because the field in the solar system is also affected by solar wind. | |
| May 24, 2021 at 13:09 | history | edited | user21103 | CC BY-SA 4.0 |
added quote
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| May 24, 2021 at 13:08 | comment | added | user21103 | @uhoh: they don't travel along the magnetic field lines: they spiral in some complex way. Quoting from the lecture notes: 'Observations of cosmic rays show that the arrival directions are relatively isotropic, and in fact the lower the energy (down to $10^{12}\,\mathrm{eV}$) the more isotropic the distribution of cosmic ray directions'. | |
| May 24, 2021 at 12:38 | comment | added | uhoh | Yes, but that's kinds my point; magnetic fields do have a well-defined direction, so the directionality of the protons that matter might deviate a lot more than 1E-03 from random. I don't think that that means there's going to be a magic place to put shielding though; your conclusions are certainly fine. | |
| May 24, 2021 at 11:46 | history | edited | user21103 | CC BY-SA 4.0 |
added 1 character in body
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| May 24, 2021 at 11:40 | comment | added | user21103 | @uhoh: I've added a note: low-energy particles have relatively small gyroradii so where they appear from is mostly unrelated to where they came from. | |
| May 24, 2021 at 11:40 | history | edited | user21103 | CC BY-SA 4.0 |
noted that lower energy particles have their directions mucked around with by magnetic fields
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| May 24, 2021 at 9:35 | comment | added | uhoh | These are for extremely high energy cosmic rays, 100's of TeV, which makes them less relevant because they are so relativistic that they are 'minimum ionizing particles though they do cause spallation. I'm not sure these isotropic super high energy particles are the ones most likely to cause health effects but I'm not sure. 1 GeV down to 10's of MeV will make it through a cabin wall and ionize like crazy at lower energy. Is it possible cite work that single out energies most likely to cause trouble? | |
| May 24, 2021 at 9:26 | history | answered | user21103 | CC BY-SA 4.0 |