Radiation is a process in which energetic particles or energetic waves travel through a medium or space. The particles or waves radiate (i.e., travel outward in all directions) from a source.

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Why spurious pulses are likely in partial discharges?

My notes The gas multiplication in the proportional counters is based on the secondary ionization created in collisions between electrons and neutral gas molecules, resulting in some visible ...
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To what altitudes does cosmic radiation penetrate?

How far does high energy (Cosmic) radiation penetrate(km above sea level) into the planet earth? And at what rate(/m^2/s)? (limited set of rates here) (The Aurora is low energy protons that stop at 90 ...
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What is the strongest material transparent to alpha radiation?

Is there a material which is transparent to alpha radiation while being able to hold up under atmospheric pressure on one side and ultra high vacuum on the other? Put simply, what material is thin ...
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56 views

Why conductors don't scatter light?

Air molecules can be oscillated by E field and re-radiate EM waves in different directions. However, if light is shined to a conductor the E field oscillate the free charges but the effect is to ...
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59 views

Klein-Nishina for estimating X-ray cross section

I'm looking at interaction probability for X-rays with water and DNA, and recently have starting reading up on the Klein-Nishina identities for differential cross section. When integrated over all ...
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36 views

Are the Van Allen belts important to life? [closed]

Is it significant for life on Earth? Mars doesn't have this. Why do experts think there may be life on it? What kind of life form could live on Mars? This article I just read got me wondering. A ...
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27 views

Can the half-life of a free neutron be calculated or is it just empirical? [duplicate]

Everyone keeps telling me its just 10.3 minutes and no one knows how to get that number form theory. Any idea?
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26 views

Proton energy distribution after Si layer

I've been using SRIM to get an approximation of the energy distribution that a beam of monoenergetic incident ions will have after a thin layer of silicon. However, for my purposes it would be better ...
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27 views

Will the background radiation get “dimmer”? If so when will it be “turned off” [duplicate]

This video http://youtu.be/_mZQ-5-KYHw talks about the background radiation which we can observe today. It's from the beginning of the universe and has traveled so long that the expansion of the ...
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49 views

Analogy for Rayleigh scattering

This morning's eclipse has me looking into Rayleigh scattering. I'm trying to think of a good analogy to explain it to somebody without getting too in-depth into electromagnetism and other subjects... ...
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40 views

Energy of black body radiation [duplicate]

Does radiated energy of black body radiation due to the transition of electrons to higher energy state? or due to the increasing vibration of atoms themselves?
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32 views

Question: if a nuclear reactor of a submarine explodes will it contaminate the surrounding waters? [closed]

After watching a Naval War movie I began to ask myself this question and I would like to know.
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34 views

Nuclear decay information

I'm looking at some gamma spectroscopy calibration data, produced by a known source (semi known... the source was last calibrated 2006...) My question is, looking at for example ...
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62 views

Energy Equation

I am reading a book on radiation and the author, while developing the equation of radiation transfer provides two forms of the equation, the second incidentally being more general and useful that the ...
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90 views

How do I build an alpha emitter?

I would like to build an alpha emitter. I suppose I had some vague idea of knocking the electrons off of some helium. But upon further examination the idea does strike me as...naive? My question is ...
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1answer
231 views

Optimal way to heat liquid from the sun?

I understand that one way to tell how much a liquid will be heated up by a remote heat source is by looking at its color. I assume clear and colorless heats up least, then white, other colors and last ...
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87 views

Effective amplitude in Neutrinoless double beta decay

Can someone give me the value of the effective amplitude($A$) of $\bar{\nu_\mu}\rightarrow\nu_\mu$ oscillation of Neutrinoless double beta decay? The expression is like this: ...
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98 views

Radiation Pressure [closed]

How much radiation pressure would be required from the sun for a carbon atom on the surface of the Earth to reach an acceleration of 1G? Can you show all the math required for the answer...thanks
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228 views

Beta decay for Ar-38, K-38, Cl-38

I want to prove that $^{38}Ar$ is stable with respect to $\beta$ decay, that $^{38}Cl$ decays by $\beta^-$ and that $^{38}K$ decays by $\beta^+$. I know from Googling that this is true, and I also ...
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39 views

Half-Life Question [duplicate]

Possible Duplicate: How do we know that some radioactive materials have a half life of millions or even billions of years? I understand how to calculate decay, but it seems to me that the ...
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290 views

How do I calculate the Radiation length of a Molecule

I want to calculate the Radiation length in a Molecule with the Formula given on wikipedia. How do I calculate Z and A for a molecule to put it into the Formula?
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71 views

Light vs. X-ray interactions with Phosphor

Looking for some information on how light and xrays interact with phosphorous, or what might cause the following: Scenario A focus beam of light is directed at a phosphor plate at the same time as ...
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1answer
48 views

$\beta^+$ decay question

I read that all baryons apart from the proton itself decay into protons (why though?) and that mesons do not decay into protons due to having less mass than protons. Thus it makes sense for the ...
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1answer
391 views

Remote EEG detection / reading

I recently noted that Philips, Accenture, and Emotive grouped together to create a proof of concept that would assist ALS patients to gain greater control of their lives through brain, voice, and eye ...
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1answer
179 views

How to solve the Fukushima incident?

I am trying to find out if it is somehow possible to take all this nuclear material, put it in some type of gamma chamber or blast it with neutrons to change the uranium isotopes into something ...
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3answers
2k views

Does brightness of the light remains constant with the variation of the distance with respect to the source in vaccum?

I have this question going in my mind from many days, i.e why brightness of light emitted from any light source around us decreases with distance? The brightness of light from tube light, streetlight, ...
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4answers
506 views

Can there be energy with no force or energy with no power?

I think that both force (number of newtons) and power (p=ui(?)) implies that there is energy so we can't have force without energy and we can't have power without energy(?) But can there be energy ...
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1answer
62 views

Need help in identification of formula [closed]

i would greatly appreciate it if someone could provide me with the concept to learn about this equation
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Measurement of heat in electrons

Is there any method to measure the heat of an electron and if there is; then is it a constant or a variable.
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Radiation from home heaters [closed]

My understanding of radiation is energy being emitted from a source. So much radiation would come out of a home gas or oil heater to become dangerous. I'm assuming infrared radiation.
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516 views

Why is signal bad in a tunnel?

Consider this: you are driving through a tunnel listening to your AM radio and a GPS, all of the sudden AM radio has nothing but statics and your GPS says "reconnecting - please hold". You say to ...
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2answers
353 views

How can we detect a black hole? [duplicate]

If black holes are phenomena of very high density (gravitational singularities) which don't emit radiation how can we detect them so far away from us where so much other radiation can hide the black ...
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1answer
918 views

Are there any radiation emitted from the cameras? [closed]

Do modern video cameras emit any kind of radiation? If so, what range of frequencies they have? I was wondering if we can detect any radiation so any help regarding detection will also be appreciated. ...
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1answer
61 views

How does a photon raise the temperature of a gas?

The temperature of a fixed volume of a gas is increased when it interacts with radiation. Why does the temperature increase (i.e. why does the velocity of a gas molecule increase) when a photon is ...
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2answers
93 views

If temperature is dependent on mass, how did the early universe have a temperature?

I am near the end of the book The First Three Minutes by Steven Weinberg. I am reading it in order to get a better picture of the early universe in the Big Bang model. But one thing I am having ...
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3answers
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Is heat from a stovetop, transfered through convection, radiation or conduction?

It doesn't appear to be convection, as there are no moving objects (or are there); probably not radiation (?), so it is conduction? I really don't know much about heat transfer and thermodynamics, ...
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123 views

Where does the “Illumination Formula” come from?

I've been studying for the pGRE for the past couple of weeks (what a load of... nevermind), and one of the questions requires the use of what is apparently deemed the illumination formula, used to ...
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632 views

What is the halving thickness of diferent materials against high energy gamma rays?

By high energy gamma rays I mean 10+ MeV to 100 MeV. Is there a way to calculate it ? Also, at these high energies, do heavier elements like Lead for example still have the advantage over lighter ones ...
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1answer
5k views

How to calculate incident solar energy on earth in a given day with a spectral filter

The daily solar radiation irradiation is often quoted as being between $3.2 \text{ kW hours}/\text{m}^2$ and $7 \text{kW hours}/\text{m}^2$ per day . If you filter out a range of wavelengths, how can ...
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286 views

How to choose a $\alpha$, $\beta$, $\gamma$ measurement detector?

There are many different detectors for different radiation,such as NaI,HpGe,CsI for $\gamma$ detection,and ionization chamber,proportional counter,Geiger counter for $\alpha$, $\beta$ detection,but ...
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955 views

What isotope has the shortest half life?

Question: What isotope has the shortest half life?
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426 views

Do and can phone signals come inside AC car which is glass-packed

Can phone signals penetrate glass, so can I expect phone signals to come if I am sitting inside a closed AC car. Thanks,
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1answer
21 views

What is the meaning of the magnitudes on the axes of this spectrum?

I'm taking a course on radiation physics and I've been given an spectrum by my professor (concretely it is a spectrum of $\left.^{22} Na \right.$). This is the first time that I come across this kind ...
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67 views

Why does the cloud chamber trails differ in length?

Why does the cloud chamber trails differ in length? Also, why does the cloud chamber trails branch into Y-shape?
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109 views

Why do grey body radiators not heat up?

So I'm doing so work on the earth's climate system, and modelling it as a grey body radiators, and I've come across the phrase: "$62\%$ of the outgoing energy is lost to space and the other $32\%$ is ...
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139 views

Does halving the intensity of a gamma ray mean absorbing half its energy?

Say a 1 MeV gamma ray is shielded by 1 cm (halving thickness) of lead. Now, what does "havling the intensity" mean ? Like will the new gamma ray exit with energy of 0.5 MeV ? and by that we can say ...
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271 views

Study of Black-body Radiation

Why did scientists study black body radiations from something as complicated as a hollow container rather than the radiation from something simple like a thin solid cylinder?
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143 views

Computing $\Delta m$ in $\beta^-$ decay

$\require{mhchem}$What is the energy $Q$ released when $\ce{^131_53I}$ decays and $\ce{^131_54 Xe}$ is formed? The atomic mass of $\ce{I}$ is $130.906118~u$ and the atomic mass of $\ce{Xe}$ is ...
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Question about Cavendish experiment

I got a question. In Cavendish experiment was used lead in both of spheres. Can we repeat that experiment with balls made from stone or anything else. Because lead could be a byproduct of radioactive ...
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3answers
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What is the difference between beta positive decay and proton decay?

Though beta positive decay's have been observed, in which a proton decays into a neutron, positron and an electron- neutrino; the why is it not the same as the exotic proton decay which is ...