Hot answers tagged cosmic-rays
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Ultra-high energy cosmic rays all come from a very, very long way away (anything with the power to create them nearby would constitute a danger to life as we know it). I think the preferred mechanism these days is dynamic acceleration in the jets formed by active galactic nuclei, but don't quote me.
Anyway, ultra-relativistic though they are, that means ...
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Great question. The electric field creates such a strong force that it would be very hard to move large amounts of just one type of charge. So astrophysical systems do generally eject equal numbers of protons and electrons. In particular, the solar wind is electrically neutral. So these cosmic rays are created in very nearly equal numbers, but by the ...
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OK, here is something concrete and quantitative, "Guidelines for predicting single-event upsets in neutron environments":
Neutrons in the atmosphere result from cosmic-ray spallation interactions with nitrogen and oxygen nuclei. A typical reaction is a 1 GeV proton fragmenting a nitrogen necleus into lighter charged particles and simultaneoously emitting ...
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The short answer is "we do" (see Pierre Auger Observatory and others1), but it's not like you can build a CMS equivalent at the one spot in the whole atmosphere where a $10^{19}\text{ eV}$ cosmic ray is going to hit next year, so we do a different kind of particle physics there.
A typical ultra-high energy cosmic ray observatory combines an array of ...
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It isn't needed in a rocket, however if you are going to the effort of sending something up outside the atmosphere (or even just high up within the atmosphere) you might as well try and get some useful data out of it. This might even help you get sponsorship for your rocket, as data from climbs through altitude is useful to a number of academic institutions.
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Between what I've learned about cosmic rays and what I can find online (example: http://www.fisica.unlp.edu.ar/~veiga/experiments.html), it seems that the primary source of neutrons in cosmic ray showers is the disintegration of the atomic nuclei that are struck by the cosmic ray or its decay products.
As you may know, cosmic rays enter the atmosphere with ...
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One must keep in mind also that it is the particle, not the shower that goes through the astronaut in dmckee's estimate above, where he treats the relativistic particle going through matter.
The shower in your question which gave the energy estimate of the parent particle is generated by cascade/sequential collisions of deep angle scattering over a ...
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Roughly yes.
Radiation is broadly divided into two from a safety point of view.
Ionising radiation can break chemical bonds and so has an obvious way to cause damage to your body - how much depends on the energy, how much radiation you absorb and where in your body it gets to.
Both X-Rays and particles from radioactive material are ionising, as is the ...
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There is the ground based observatory ( nice picture) Veritas.
VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a major ground-based gamma-ray observatory located at the basecamp of the Fred Lawrence Whipple Observatory in southern Arizona, designed to observe and study very-high-energy (VHE) gamma-rays (energies above ~100 GeV).
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Energetic cosmic rays are rare, as @John Rennie states in his answer, and the detectors to measure their effect cover kilometers. One high energy entrant creates what is called an air shower and it is measured as @dmckee describes.
It is not possible to use them as an incoming beam because we do not know what they are ( except in the case of gamma rays and ...
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One major problem with this proposal is that the cosmic ray hits a particle at rest, not another cosmic ray with the same energy going in the opposite direction. Under these conditions, if a cosmic ray proton at enormous energy E hits a proton at rest with mass m, the center of mass collision energy is found by boosting to the rest frame, and the result is a ...
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We actually use cosmic rays to study fundamental physics. Thanks to them we discovered the muon and the positron many years ago, as you probably know, and currently they imposes severe constraints on violations of Lorentz invariance.
The tension between cosmic ray physics and accelerator physics is the tension between observations and experiments. In the ...
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Muons are the main cosmic rays reaching sea level with a possibility of interacting with matter. Neutrinos interact very weakly and need special detectors to be seen at all.
Rule of thumb when I was working with counters is that the flux of muons at sea level is 1 per cm^2 per second, wikipedia gives this number for over 1 Gev
The number of particles ...
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First of all terminology:
When physicists speak of radiation they primarily speak of electromagnetic radiation. When health physicists speak of radiation they include radiations of other types, alpha and beta and neutrons in addition to gamma and xrays. They have developed a system where radiation is given in Becquerel ignoring the particular source.
So ...
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For the most part cosmic rays do nothing to consumer electronics.
This is not to say that they can't flip bits or even damage elements, but the rate for such effects is very, very low.
Radiation effects are routinely observed in electronics placed in accelerator experimental halls (where the radiation levels are at lethal-dose-in-minutes levels when the ...
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Muon catalyzed fusion needs the muons to be low enough energy to replace an electron and stay in a stable orbit. Since the reason the catalysis happens is because the atom is much smaller and two protons can get close together enhancing the probability of overlap and fusion, one needs a large number of low energy muons so that the probability of two muonic ...
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Moun catalyzed fusion requires very specific kinematics, but cosmic muons come in all energies from stopped to tens of GeV at any particular spot.
Care to work out the cross-section for having the right kinematics? If you're having trouble I know a graduate student who is familiar with several of the common cosmic muon Monte Carlo generators.
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These are rare, on the order of one per square mile per century. See Ultra-high-energy cosmic ray (Wikipedia). So a human, with a cross sectional area less than 1 square meter might get hit about once per each 100 million years. I think that the risk of life due to spacecraft malfunction is significantly greater than this.
And when they do hit the Earth's ...
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Spallation of air atoms' nuclei is the easiest way - there are neutrons kicked out of the nucleus directly or emmited by radioactive elements, which were activated by cosmic rays.
Also neutrons can be produced upon hadronization of quark-gluon-plasma or from electron capturing in air nuclei.
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because this is the most probable configuration. Black-body light is the thermal equilibrium for light, so that anything that produces light which has a finite energy produces light that knocks around eventually to become blackbody light. The light we see was scrambled during the first 300,000 years by innumerable collisions with electrons and nuclei, and ...
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If the range of energies of cosmic rays is not so far away respect to gamma's,
The range of energies of cosmic rays goes from a few keV (muons at sea level) to 10^20 ev.
The original particles may be alpha particles, protons, neutrons, gamma, neutrinos etc and when they impinge on the atmosphere they create air showers and a number of pions kaons etc ...
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You're right to be suspicious of things making it through the entire atmosphere unimpeded. Most of what Carl Anderson was detecting were the secondary showers of electrons and positrons produced when a high-energy proton (or sometimes another particle) from space interacted with matter. (It's not open-access, but here is the paper in which Anderson shows ...
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Annihilation can happen when all the quantum numbers of two colliding particles add up to zero. It might be electron on positron, proton on antiproton, neutron on antineutron , quark on antiquark etc.The force responsible depends on the possible interactions of the annihilating particles.
In the case of electron positron annihilation it is primarily the ...
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Cosmic rays do have noticeable affect on electronics. The most prevalent effect is from memory bit flips (known as "soft errors").
The degree of significance of the effect depends on the application. A typical soft error rate for static RAM is in the region of 400 FITs/Mbit [1]. (Failures in time=failures per billion device hours) So if you have 1 Gb of ...
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Of course.
Essentially any ionizing radiation can diddle DNA. Altering the DNA in most bodily cells may kill that cell or cause it to misbehave in various ways (including cancer). Or it may do nothing at all (for instance, if it lands on a unused portion of the strand, or turns off one of several copies of a particular genetic switch).
Any ionizing ...
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JEM-EUSO is designed to look for air showers caused by extremely high energy cosmic rays (>$10^{19}$ eV). According to the website, it will be attached to the International Space Station in 2016.
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For example, neutrinos from a Supernova was detected in 1987 (and it seems that was the only observation of this kind). Cosmic rays from outer space are also observed, but I don't know if their source can be identified precisely.
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It is difficult to detect very high energy cosmic rays in space. The reason being that to detect them one needs to interact with them. And an interaction is determined by how much material you put in its way. After you interact, you get massive showers of very high energy particles so you need lots of detectors to detect these. Getting big heavy detectors ...
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There are particle detectors in space right now, and many more planned. They not are to used to study ultra-high energy cosmic rays because those puppies are very, very rare indeed.1 Instead they study electromagnetic bands that do not penetrate the atmosphere and cosmic rays a more ordinary energies.
1 Large scale ground arrays coupled with air ...
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Black body radiation is a bit misleading name, as it may also refer to the equilibrium radiation. The two have different conditions, but they follow the same frequency distribution, i.e. Planck's law.
Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by ...
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