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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Non-ionizing particle radiation
First of all: I'm new here so please forgive me if my question doesn't meet the standards of this community.
My question is as follows: Does there exist non-ionizing particle radiation?
I know that ...
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Do you have to know which radiation type are you measuring with a geiger counter to correctly estimate the equivalent dose rate?
for a while now, I have been working on my own DIY geiger counter. I was able to make some more or less functional devices, which all were working around old soviet SBM-20 GM tube. I want to do a ...
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Proof that thermometer will measure higher temperature than that of an enclosure if radiated heat is same in all directions
I am reading the English translation of J. Fourier book "The Analytical Theory of Heat".
In para 47, the author states "If the rays which escape from a heated surface had the same ...
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Explanation percentage of emissions for $\alpha$ / $\beta$ / $\gamma$ decay
For Cobalt and Americium, why is the alpha decay for Americium not $100\%$ but $85\%$ & $13\%$ whereas for Cobalt it is all $100\%$
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How does Neptunium-239 gain an electron after Uranium-239 beta decays?
I'm reading Richard Rhodes' book on the creation of the atomic bomb, and and we've reached the point of creating Plutonium by bombing U-238 with neutrons. I understand how U-238 absorbs a neutron and ...
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Oscillating dipole, longitudinal Electric field oscillation?
Assuming the presence of a dipole consisting of two oscillating point-like charged particles on the z axis. Lets say whose motion follows $q_{\pm}=\pm 1\pm \frac{1}{2}\cos(\omega t)$, it is a well ...
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Why is my dryer radioactive?
My Geiger counter measures a background radiation level in my home of 0.09–0.11 μSv/h.
When I stick it inside the dryer right after it finishes a cycle (while the clothes are still inside), it ...
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In what form is the binding energy released after nuclear fission?
This is too primitive question. but I cant find a definitive answer anywhere.
Everywhere its mentioned that Binding energy is released in the good-ol uranium 235 and uranium 238 nuclear fission.
Where ...
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Why are CT scans much smaller than the raw data?
I'm not too familiar with CT, but I worked with medical CT images long ago, and recall that the raw data, recorded by the scanner was way bigger than the 3D image itself (Both were 16-bit TIFF files, ...
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Cavity radiation and number of modes
Cavity radiation says the number of modes in the cavity increases with frequency, or shorter wavelength, because more modes can fit in. But consider a square box with sides L with a small hole. EM ...
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Compton Scattering Notion
I have been reading about Compton Scattering and got confused about exact technicalities. So forgive me if I ask multiple questions, but all related to each other. This is due to the fact that you don'...
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6-day curie to grams?
I am a pre-med interested in nuclear medicine. I recently came upon this wonderous radioisotope called Mo-99 (which decays into Technetium-99m), but in their industry, they measure the quantity of ...
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How does inner Bremsstrahlung work?
I'm trying to understand inner Bremsstrahlung. I know this applies to beta minus decay, but have a hard time understanding how it works. In the beta decay, electron is emitted from nucleus. I believe ...
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Is using a variable based on near infrared radiation to predict a variable based on thermal infrared a circular exercise?
I am creating a model which aims to predict a Land Surface Temperature related variable (from satellite thermal infrared measurements) which uses a vegetation related variable (created using satellite ...
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Do blackbodies emit gravitational waves?
It was previously my understanding that the reason blackbodies only emit light was because light was the only massless particle, so there exist excitations of the electromagnetic field of arbitrarily ...
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Can Neutron Activation Analysis differ isotopes?
I know to carry out an NAA analysis, the specimen is placed into a suitable irradiation facility and bombarded with neutrons. This creates artificial radioisotopes of the elements present. Following ...
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When can a sum of exponential decays be approximated by a single exponential decay?
In my experiment, I have a signal y(t) that should be given by a continuous sum of exponential decays:
$y(t) = \int_a^b n_0(E) \exp[-t/\tau(E)] {\rm d}E$
However, I see just a single exponential decay....
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Beta particle range
I was working on an experiment using the Geiger counter to determine the range of beta particles through different materials. The range is to be determined experimentally and compared to the ...
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Excitation of Nucleus on emission of alpha or beta particles
I was reading my notes (the topic is called 'nuclear chemistry') today when I noticed a line
"alpha (He2+) and beta (e-) can't be emitted simultaneously. After emission of alpha or beta, gamma ...
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Simulating $e^-\rightarrow e^-\gamma$ scattering in QED
Is there any physical reason/symmetry prohibiting me from studying the $e^-\rightarrow e^-\gamma$ interaction? Because I haven't seen any QFT textbook dealing with such a simple process. It is the ...
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Maximum and Minimum electron energy
I am trying to find the maximum and minimum electron energy for the calculation of the beta spectrum. I understood the minimum energy of the electron is the Q value. What is the maximum energy of the ...
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Clebsch-Gordon coefficients for isospin transformations
I'm trying to understand a paper in which the author uses the nuclear matrix elements from beta decay to arrive at the matrix elements for neutral-current neutrino-nucleus excitation. The author ...
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Non-irradiative methods to create radioactive isotopes?
My understanding is that the primary methods with which one can create a radioactive isotope are 1) just waiting for the isotope you want (by means of nuclear decay), or 2) some kind of induced ...
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Equivalent absorbed radiation dose exposed to Electron Microscopy Beam
I'm intentionally exposed an Integrated Circuit (IC) to electron beam under a SEM Microscope. I have different accelerating voltages and different current beam parameters to be adjusted.
For example, ...
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Non-Monochromatic Bloch Equation
Is there literature on the Bloch equations with non-monochromatic radiation field? I.e. for a system with interaction Hamiltonian of the form $H_I = g \vec{E} \cdot \vec{\sigma} \sum_{i} a_i \cos(\...
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Accelerating charges [duplicate]
Considering the fact that accelerating charges radiate, thereby losing energy and magnets are made up of tiny dipoles that consist of spinning electrons, why doesn't the magnet radiate and eventually ...
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Why are characteristic X-rays produced in greater numbers than bremsstrahlung rays?
In a typical X-ray spectrum we can observe that characteristic X-rays occur in noticeably larger numbers compared to other energies.
Characteristic emission is a separate phenomenon from ...
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How does fire heat air?
I understand that fire heats its surroundings via conduction, convection and radiation. I've read that conduction is nearly irrelevant to this process as air is a poor heat conductor. In descriptions ...
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Radioactive Decay of Li-8
Currently using a simulation to observe the decay of various elements. I noticed for the Li-8 there is beta decay. There are also arrows pointing from beta decay towards alpha decay and stable. Can ...
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Does thermal energy include the energy of thermal radiation as part of its definition?
I can't get a simple answer to this simple question online, so I thought I'd ask here.
Thermal radiation is usually meant to be the energy associated with a given temperature of a material body. Now ...
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Anisotropic radiation from excited nuclear states
I come from particle physics background, but I want to understand something related to nuclear physics. I don't have any training in nuclear physics, but please feel free to share any equations.
If ...
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$Q$-Factor for Beta Decay
I am struggling to understand the $Q$-factor for the $\beta^-$- decay process. My understanding of the $Q$-factor is that it's the difference in binding energies before and after the chemical reaction....
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Will gravitational waves decay into photons? (and by how much?)
We know intense regions of curvature, for example near a black hole horizon, induce a flow of electromagnetic waves (and, less so, other particles). aka Hawking radiation.
By contrast, curvature in ...
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Is 1 Sv of alpha Radiation just as or more harmful for living beings than 1 Sv of Proton radiation?
Is 1 Sv of alpha radiation just as or more harmful for living beings than 1 Sv of proton radiation?
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Does vibrational energy transfer to translational energy when an excited $\rm CO_2$ molecule collides with an $\rm N_2$ or $\rm O_2$ molecule?
My understanding is that when a $\rm CO_2$ molecule absorbs a photon of heat in the atmosphere after some time it simply re-emits that photon in a random direction. If that photon makes it back to its ...
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What are infrared and collinear safety?
I'm studying particle jets for the first time and I do not understand what "collinear" and "infrared" safety (which are two requirements that a method for counting jets in an event ...
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How do non-periodically varying currents produce electromagnetic waves?
Electromagnetic radiation is created by the varying/accelerating of a system of charges and currents. Suppose that the time dependence of the charges and currents are $\rho(x,t)$ and $J(x,t)$. Then ...
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Averaging transition rate for absorption in dipole approximation for unpolarised radiation
The transition rate corresponding to the first-order probability of absorption is given in the dipole approximation as
$$W_{ba}=\frac{dP_{ba}^{(1)}}{dt}=\frac{\pi I(\omega_{ba})}{\hbar^2 c \...
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Harmonic perturbation in interaction of radiation with quantum system; making sense of approximation of the integral
In the chapter "The interaction of quantum systems with radiation" (Quantum physics book by Bransden and Joachain, 2nd edition) section 11.2 "Perturbation Theory for harmonic ...
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Can a thermal radiating surface be replaced by an equivalent antenna with proper current distribution?
Thermal radiation is EM waves generated by electrons movements due to a non-zero absolute temperature. Given a certain material with such an emission at temperature T, is it possible to see it as an ...
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Synchrotron radiation and Hawking radiation [closed]
According to 1 answer I came across:
"There is a myth, for which Hawking himself is responsible, that
Hawking radiation is primarily made up of matter-antimatter pair
annihilation."
The ...
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Why is Astatine-210 (At-210) the longest-lived isotope of astatine despite possessing an odd number of neutrons?
I am guessing that isotopes with an even number of neutrons more readily release an alpha particle... When and if At-210 does that, it still has the problem of being 'odd/odd'...
But this begs the ...
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How to treat the thickness of materials in dual energy computed tomography (CT)? [duplicate]
In computed tomography (CT) imaging, the dual energy CT extracts the mass density of two materials based on linear mass attenuation. With two measurements at two different energy, the dual CT can ...
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Can the optical depth vary in a cloud of homegeneous temperature and density?
For the cloud in the title, could $\tau \gg 1$ in one spatial direction and $\tau \ll 1$ in another? Since its density is homogeneous, I think $\tau$ would be the same in any direction if we measure ...
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How do surface temperatures drop in response to optical depth?
I'm trying to come up with a super simple estimate for how atmospheric surface temperatures would be affected by a substance overhead with some optical depth $\tau$. I'll assume that the sun is always ...
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Do gases emit radiation at all wavelength? [duplicate]
According to Planck's law, all matter emits radiation at all wavelengths but is this statement true for gases and pure elements? Gases like hydrogen and helium have specific emission spectrums and I ...
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Do all matter emits radiation at all wavelengths? [duplicate]
Does all matter emit radiation at all wavelengths? Do gasses also emit radiation at all wavelengths since they have a specific emission spectrum? Shouldn't they only emit radiation according to their ...
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Why does absorbed dose increase with increasing tube potential in computed tomography?
In X-ray radiography it is a common technique to reduce patient absorbed dose by increasing the X-ray tube potential (kVp) while keeping the detector exposure constant by decreasing the tube current-...
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How can imparted energy be a stochastic quantity?
It may be a silly question, but I have a dosimetry course and it started by defining deposed energy and imparted energy and for both it says that they're stochastic quantities. The mathematical ...
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Depth ionization $\neq$ depth dose for electron beam?
Consider an electron beam which is targeted towards some object with a certain depth. The concept of dose refers to the amount of energy expended by the electrons in collisions with atoms of the ...
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