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Questions tagged [radiation]

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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Harm from gamma radiation compared to beta radiation

why is a small dose of gamma radiation less harmful than a small dose of beta radiation? even though gamma radiation is more penetrating. This is a question I was wanting to know and had difficulty ...
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What is wrong with my Cloud Chamber? I can't see supersaturated vapor or particles [duplicate]

I'm using black felt at the bottom, a small tin can, and black sponge around the inside of the can. I hot glued them onto the can, and then put 91% isopropyl alcohol in it. Afterwards, I used some ...
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Heat/gain loss through radiation (question below):

Many modern houses in colder countries are designed to conserve energy. State the colour that the outside of the house should be painted to reduce heat loss. My initial thoughts were that the house ...
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Is this the correct interpretation of specific intensity?

I've always been taught to define specific intensity as the following quantity: if I have a detector here next to me with an area element $dA$ and I detect a power element $dP$ from a source of solid ...
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How do the probabilities in decay schemes work? (Ir-192)

I'm incredibly confused as to how the probabilities work in decay schemes (Particularly for Iridium-192). There are the green numbers to the left of the image that appear to add up to the total ...
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Can radiation light up a fluorescent light?

Watching the excellent but horrific HBO Miniseries Chernobyl. There is a scene where the radiation level is so strong, it ruins the batteries of flashlights being operated inside the plant, in the ...
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Calculating radiative heat transfer between air and walls, what to use for the emissivity of air?

For example, say I have heated some air, I push it through a tunnel with cold black walls. Will the air radiate heat to the walls or will the walls radiate heat to the air? I understand that the ...
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Does an atom or proton (cosmic ray) get stretched when traveling through expanding space?

I have read this question: Why does space expansion not expand matter? I do understand that matter inside galaxies will not get stretched because inside galaxies, gravity dominates over dark energy. ...
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Energy radiated/emitted by an object in a black body environment?

What is the net energy radiated per unit time by a black body at temperature $T$ with emissivity $e$ and absorptivity $a$, if it’s placed in an environment of temperature $T_o$.Assume that $T$$\gt$$...
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What part of the energy applied to accelerate electrons radiate and why?

I understand that accelerated electrons will emit radiations, for example in a cyclotron or antenna. However I dont understand why some energy will sort of stay in the electrons and accelerate them, ...
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Function of distribuction (muons)

Does the number of muons from the atmosphere measured by two Geiger detectors (coincidence method) follow a normal distribution or a beta distribution? Why?
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Confusion in Positron Decay

As we know, in a positron decay, by the involvement of weak forces, a proton converts into an neutron, emitting a neutrino and a positron, all of this happens inside the nucleus. Why doesn't the ...
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Speed of beta-decay ejected electrons

It is well known that the energy spectrum of the beta-decay electron is continuous; it was confirmed by the Ellis and Wooster 1927 experiment. It means the electron are ejected with speeds that may ...
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Question on two-neutrino double electron capture

There was a fascinating paper in Nature recently, on the observation of two-neutrino double electron capture in xenon, with a half-life time of $1.8\times 10^{22}$ years. The process described in the ...
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What happens after barium sulphate absorbs gamma rays?

BaSO4 will happily absorb gamma-rays, presumably bumping electrons up into outer orbitals. What happens next? I assume fluoresence as electrons drop back. Will the BaSO4 be safe to handle immediately ...
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Radiation heat flux of a material surrounded by another material of different emissivity

The radiation heat flux of a material is calculated according to the formula mentioned in the following website: http://web.mit.edu/calculix_v2.7/CalculiX/ccx_2.7/doc/ccx/node234.html#radiate But ...
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Why is radiation dangerous? [closed]

From Wikipedia: Exposure to radiation causes damage to living tissue; high doses result in Acute radiation syndrome (ARS), with skin burns, hair loss, internal organ failure and death, while any ...
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Will a 100MeV muon and a 50MeV muon deposit a different amount of energy in a scintillator?

I have a question where I need to calculate how much energy a $100\,\mathrm{MeV}$ muon will deposit in $1\,\mathrm{cm}$ of scintillator. I know that the muons lose energy about $2\,\mathrm{MeV/(g/cm^2)...
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Why is anti-neutrino produced along side with electron in beta minus decay? [duplicate]

so i get that when there is an excess of neutrons, neutron is converted into a proton. An electron is produced to neutralise the +1 charge of proton. But why is an anti neutrino produced?
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Where does the kinetic energy of an object annihilated in a matter antimatter reaction go?

A bullet is moving at $0.99 c$. Now we annihilate it by having it collide with an equal mass of antimatter. (assume instant and perfect reaction) This will turn both bullet and antimatter into photons....
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Why is the actual KE value smaller than what I calculated?

Problem The nuclear equation for the decay of calcium-47 into scandium-47 is given by: The following data are available: Mass of calcium-47 nucleus = 46.95455 u Mass of scandium-47 nucleus = 46....
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What is the atomic number of an electron, and why is its symbol $\sideset{_{-1}^{\phantom{-}0}}{}{\text{e}}$ in $\beta^{-}$ decay equations?

I'd assume that the atomic number, i.e. the proton number, of an electron is $0$ given that it doesn't have any protons. However, to balance beta minus decay equations, this source seems to claim ...
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How much radiation do nuclear physics experiments expose researchers to nowadays?

I am curious about how much radiation do experimental nuclear physics researchers/students suffer in nowadays research environment. I know this may be a dumb question, but I have can found answer ...
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Why use gamma over alpha radiation?

In radiotherapy, the goal is to kill as many cancer cells in a localised area without killing normal cells right? So what possible reason would there be to use gamma irradiation over alpha irradiation?...
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The Magnetic Field Strength of Crab nebula

Consider the spectrum of the Crab nebula shown below. Assuming that the ~TeV photons are produced by Inverse Compton scattering of synchrotron photons from around the peak of the synchrotron ...
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What happens to the electron when a neutron knocks off a proton from hydrogen atom?

In recoil proton scintillators, the hydrogen acts as a neutron converter to produce protons when a neutron strikes a H atom. But what happens to the electron in H atom? Where does it go? Does it ...
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Is Sun brighter than what we actually see?

I learned from that plasma can reflect radiations of frequency less than that of its own oscillations. If so, considering the plasma in Sun's atmosphere, it should also reflect solar radiations. That ...
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Radiation Pressure at oblique incidence

Consider case of absorption Here the force due to light is given by $F=\frac{IA\cos\theta}{c}$ This force is perpendicular to the surface. So the pressure due to this force should be $\frac{F}{A}$, ...
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Lee and Yang's 1956 Paper

I've been reading Lee and Yang's paper that looks into the possible of parity violation. You can find it here: A Question on Parity Conservation in Weak Interactions. And they say This phenomenon ...
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Detection of radiation levels using gas filled detectors

As we know that detection efficiency for gas filled detector is low, then how we use them to detect radiation levels inside X-ray or nuclear medicine department rooms ? Won't they be giving false ...
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Clarification on isotope notation

I am a bit confused about the idea of isotope notation. I know that the top number is the mass number, equivalent to the number of neutrons + protons, while the bottom is the atomic number, equivalent ...
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Would manganese, iron, osmium,fluorine or nitrogen cations hold a higher linear energy transfer than carbon cations?

Is linear energy transfer in particle radiation therapy directly proportional to the particles' density? I.e directly proportional to the mass and inversely directly proportional to the volume? If ...
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The law of radioactive decay: explanation of a formula

The law of radioactive decay can be expressed in terms of $\,\tau=1/\lambda$ (average life) as: $$ N(t)=N_0e^{-t/\tau}, \quad \tag{1} $$ Why deriving the (1) I ...
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Radiation pressure at a surface which is perfectly refracting

Radiation pressure at perfectly reflecting surface = 2I/c Radiation pressure at perfectly absorbing surface = I/c What will be the radiation pressure at a perfectly refracting surface? Will it be ...
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Calculating the shielding required to protect against radiation at lunar orbit

I am attempting to calculate the thickness needed to protect the crew inside a space module at the Lunar Orbit with Lithium Hydride from X and Gamma Rays. How would I calculate the thickness of Li-H ...
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What is the formula of operating voltage of GM counter?

In some manuals I found operating voltage formula $$V=V_1+(1/3)(V_2-V_1)$$ and in other manuals $$V=(V_2+V_1)/2.$$ Which formula is correct? If both are correct, then please give the reason.
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Light from an incandescent lamp

In a tungsten filament lamp, electrons travel through a high resistance path,due to which the temperature is increased. Now why does it emit light , is it because of the transitions of electrons from ...
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How are free electrons reincorporated into orbits?

In particular, I'm curious about what happens to beta particles once they lose most of their kinetic energy. As I understand, they'll eventually find their way into orbits of surrounding atoms, but ...
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Possible to detect presence of nuclear bomb? [closed]

Take, for instance, a W-80 nuclear warhead. Does technology exist, say in the form of a satellite or drone, that could detect the warhead's presence (assuming it's not enclosed in some kind of ...
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Experimental beta decay spectrum of free neutrons below 150 keV?

From a pedagogical point of view, beta decay is a really sweet example of relativistic kinematics, and seemingly the best and most natural example to use would be the decay of free neutrons. This is a ...
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Why does a scintillator need to be fast decaying?

I have two scintillators, say, one with a decay time of 1 ns vs. one with 100 ns. All other parameters like light yield, size of crystal, electronics used, source emission rate, are the same for both. ...
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Brehmsstrahlung radiation query - If an electron is constantly being decelerated, how does it emit a photon with a fixed energy?

According to my textbook they simply say an electron is decelerated by a nuclei and this means it loses KE. The difference in KE is given off as a photon. But an electron is always being pulled back ...
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Bremsstrahlung photon energy query

In my textbook they've defined the energy of a photon released by an electron decelerated by a nucleus to be the difference in its KE before and after being decelerated by the nucleus. However I was ...
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Gamma from U238 decay chain

Where can I find detailed information on the gamma background from the U238 decay chain? Edit: Thank you for your replies. I need to find all the branching ratios and extract information of all the ...
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Spectrum of beta decay

I have a very simple question regarding the emission spectrum of a beta decay: Why does the $\beta^+$-spectrum start at $0$ but the $\beta^-$ doesn't? This would mean that there are a bunch of ...
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Scintillator decay time=1000 nsec,does that mean dead time is really high?

What I'm really confused about is, say my scintillator is really slow, and has a decay time of about 1000 nsec. Does that mean, if one neutron is being read by the electronics, for that particular ...
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Has there been any R&D(let alone progress) in the development of gamma voltaic cells?

I ask this because it is my understanding that gamma rays form ion tracks and oxygen radicals when gamma emitting material is immersed in an aqueous solution. Cesium-137 is a very strong gamma ray ...
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Electric quadrupole radiation and supernova core collapse

I have a question when I'm learning the electric quadrupole radiation in E&M. In the radiation zone, the vector potential $\vec{A}(\vec{r},t)$ generated by the current distribution $\vec{J}(\vec{r}...
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Questions regarding germanium detector

Why n+ contact in n type Ge is not several hundred microns? . Why we require both additional p or n type contact? in p type Ge, why we require additional p type junction also? crystal itself should ...
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Radiative Transport Equation scattering phase density probability term question

The development of Radiative Transport Equation has a contribution term called the scattering phase density probability function. It account to scattering events from photons from a different solid ...