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.
1,534
questions
-1
votes
0
answers
39
views
What is the entropy change as an alpha particle is stopped in air?
Consider a single alpha particle in a box full of air, how does the entropy change as the alpha particle comes to a stop?
Assuming all forms of stopping, Bethe-Bloch Stopping, head on nuclear ...
- 1,010
-5
votes
2
answers
72
views
why are nuclear fallout shelters really necessary when radiation fades with distance so quickly? [closed]
why are nuclear fallout shelters really necessary when radiation fades with distance so quickly?
it diminishes with the inverse square law. I1xD1^2 = I2xD2^2. (Standard procedure is to measure ...
- 1
-1
votes
0
answers
34
views
From the activity of decay products produced within an interval, may the activity of the parent source be obtained through the decayed particles? [closed]
To calculate parent activity from progeny, may the percent particles decayed be multiplied by particle quantity, thence the decayed particles employed to determine the activity? I have created these ...
1
vote
2
answers
25
views
Why does the color of a body only depend on absorptive power and not emissive power?
In the numerous explanations on nets and books, all give the reasoning as follow. If you see a red shirt, it's because that pen had a higher absorptive power for all colors except red, causing its ...
- 11
2
votes
0
answers
29
views
How did Kurlbaum and others measure the intensity of each wavelength to get blackbody radiation curve?
In 1900 Plank was faced with data that didn't agree with the Plank-Wien law. This data that plots different temperature curves - wavelength on the horizontal and intensity on the vertical (or rather ...
- 21
-2
votes
0
answers
28
views
What is the activity in Curies of the Radon-222 produced by 1 Curie of Radium-226 in one day? [closed]
What is the activity in Curies of the Radon-222 produced by 1 Curie of Radium-226 in one day?
Is this scalable, and with it can the Radium activity be derived from the Radon activity?
Thank you!
3
votes
2
answers
190
views
If we have a beam of photons and a beam of protons with the same energy, which one will get further inside the human body?
If we have a beam of photons (high energy X-ray) and a beam of protons both with the same energy, which one will get further inside the human body and why? Can this be explaind due to LET (Linear ...
- 51
0
votes
1
answer
45
views
Can Alpha Decays and Gamma Decays be expressed via Feynman Diagrams?
I just learnt about Feynman Diagrams, and I've been going through many examples to practice the reading of Feynman Diagrams myself. I have already found diagrams for Positron Emission, Electron ...
0
votes
1
answer
46
views
Help Understanding Spontaneous Alpha Decay [duplicate]
I've been reading through my Physics textbook (College Physics 2e on OpenStax) and I'm a bit confused by how it explains when alpha decay is spontaneous. Here is the quote for context:
When the final ...
0
votes
0
answers
37
views
Derivation for Quantum optics dipole radiation formula
An often used formula for the radiation field of a dipole is the following one:
\begin{align}
\vec{E}(t, \vec{x}) = \frac{1}{4 \pi x^3} ( 3 \hat{x} [ \hat{x} \vec{d}(t_r)] - \vec{d}(t_r) ) + \frac{1}{...
- 6,634
4
votes
1
answer
67
views
How to compute the magnetic vector potential in the radiation zone due to a charge density from Thomson scattering?
Context
In the course of studying Thomson scattering, I obtained a current density described by the equation
\begin{align}
\mathbf{j}(\mathbf{r},t)
=&
\frac{ e^2\,E_\text{inc}}{ m\,\omega}
\,
...
- 392
0
votes
1
answer
38
views
$\rm NaI$ detector calibration with $\rm Cs$-137 and $\rm Co$-60 using Genie-2000 software [closed]
I have tried to calibrate the NaI detector with the NIM set, Cs-137, Co-60 radioactive sources and Genie 2000 software.
I used Cs-137 first and corrected the channel energy then used the Co-60, only ...
0
votes
1
answer
47
views
Solid state X-ray detector response to environmental background & cosmic radiation
I would like to know what exactly is the "ticking" sound produced when using solid state Unfors Survey detector, i.e., when it is connected to its Xi Base unit and turned "ON" in ...
0
votes
1
answer
31
views
The energy axis for beta spectrum and Antineutrino spectrum
I am trying to plot an antineutrino spectrum and I was wondering whether the x axis has same range of energy values as the beta spectrum? I am taking the range of energy values to be from 0 upto ...
- 29
0
votes
2
answers
168
views
If the time at which a single atom decays is random, why do groups of atoms behave in predictable ways? [duplicate]
Why do groups of atoms decay at predictable rates even though a single atom’s decay point is completely unpredictable? I’m having trouble wrapping my head around this.
From my reading, it seems that ...
- 281
22
votes
3
answers
2k
views
Does free neutron decay create a hydrogen atom?
When a free neutron decays, it is transformed into a proton, an electron, and a neutrino. Does this electron begin to "orbit" the proton, forming a hydrogen atom? Or does the electron run ...
0
votes
0
answers
29
views
Difference between $Q$ value and Total energy in a beta minus decay
I was going through the kinematics of beta minus decay. I understood that the $Q$ value in the beta minus decay is the sum of the KE of electron and anti-neutrino
$$Q= E_e + E_\nu.$$ Here the $E_e$ ...
- 29
0
votes
1
answer
66
views
What is the importance of excited states in the emission of gamma radiation during alpha decay?
Let's suppose that during a hypothetical alpha decay of a nucleus X, has two excited states (such as 2.3 mEV and 0.9 mEV) are respectively fed.
The question arises here: what would would be the energy ...
- 3
-3
votes
3
answers
108
views
Why can gamma rays penetrate a thick layer of lead and why can't a beta particle penetrate a thin sheet of aluminum?
This might be a stupid question, but, why is it that gamma rays are able to penetrate almost any barrier without question? We know that gamma rays are simply high frequency waves with massive amounts ...
- 57
0
votes
1
answer
59
views
Physics behind Uranium metal bars being "self-shielding"
I was looking through some old documents and pitching them from my time at uni. In there, I found some materials handling notes, and one regarding the handling Uranium metal bars. Basically, it said ...
- 101
0
votes
1
answer
63
views
Is nuclear fission just induced radioactive decay?
So, I've just been learning about chemistry recently and I came across the isotopes of an atom, which are obviously the different numbers of neutrons within atoms of the same element (i.e. same number ...
0
votes
1
answer
67
views
Difference between endpoints and kinetic energy in a beta minus decay
I want to understand the difference between the Q value and Endpoint energy and Kinetic energy of a beta minus decay.
I understood that the Q value is the overall energy of the reaction given by
Q ...
- 29
1
vote
0
answers
36
views
Water molecule formed by at least one tritium atom
If a water molecule is made up of at least one tritium atom, when the tritium atom(s) decay radioactively, what happens to that water molecule? Does it bond to one or two Helium atoms? Is there any ...
- 11
-1
votes
1
answer
56
views
Interpretation of watts per square meter for intensity of radiation
The energy that an electromagnetic field can deliver to a system is proportional to the square of the field. However, we use the terminology watts per meter square to represent the amount of energy ...
- 3
0
votes
1
answer
52
views
Nuclear decay formula derivation
I don't understand why the nuclear decay formula is derived with logarithms.
if $t=T_{1/2}$ then
$N=N_0\cdot\frac{1}{2}$
if $t=2T_{1/2}$ then
$N=N_0\cdot\frac{1}{2^2}$
if $t=3T_{1/2}$ then
$N=N_0\cdot\...
- 5
0
votes
0
answers
23
views
Apart from the KE of the positron and neutrino, where does the remaining transition energy go during beta-plus decay? [duplicate]
Apart from the KE of the positron and neutrino, where does the remaining transition energy go during beta-plus decay? What is the 1.022 MeV minimum energy transition used for?
3
votes
1
answer
123
views
Hamilton function of a point charge
In Fermi’s 1932 paper, Quantum theory of radiation, he wrote a “Hamilton function of a point charge in radiation field”
I am not able to get how to derive this equation. I have also looked up at ...
0
votes
1
answer
53
views
Jumps between energy states of harmonic oscillators
I have recently read that in perfect harmonic oscillators to go up or down in energy state you have to go, using the simile of a staircase, step by step, emitting or absorbing a photon of energy $E=\...
2
votes
4
answers
114
views
How does an antenna emit photons at a specific frequency if the antenna is made up a specific metal (Al) for example?
My base assumptions...
An antenna emits energy over long distances in the form of photons.
A photon is emitted when an electron changes energy state from higher to lower levels.
A photon's "...
- 21
1
vote
0
answers
71
views
Can alpha radiation make other materials radioactive?
Most general sources that describe the basics of ionizing radiation assert that the only type of radiation that can directly make other materials radioactive is neutron radiation (via "neutron ...
- 111
0
votes
1
answer
28
views
Why do some nuclei decay by Neutron Emission?
Alright so I am confused somewhat about Neutron Heavy Nuclei not decaying, or more specifically why it is that Neutron Heavy Nuclei sometimes decay by emitting Neutrons.
Someone has already answered ...
- 101
0
votes
0
answers
40
views
Tritium Decay and He-3, $n$ reaction
I have two separate questions that I have simply not been able to find any answers to:
With regard to Tritium decay to He-3, I'm a bit confused as to why Tritium is unstable based on its $n$ to $p$ ...
- 1
0
votes
1
answer
26
views
From where does the particle in liquid get energy to move always?
My question is that if there is an object,then without giving energy to an object it cannot move …so my question is that how do particles in fluids always move without giving them any additional ...
- 177
0
votes
0
answers
46
views
Charged particle equilibrium and Bragg-Gray cavity theory
About the charged particle equilibrium: 'In a small volume in the radiation field, some secondary electrons generated in the volume escape from the volume, and some electrons generated outside the ...
- 11
0
votes
0
answers
25
views
Is Newtons Law of cooling applicable for all forms of heat loss? [duplicate]
Can heat loss through Conduction, Convection and Radiation be explained by Newton's law of cooling?
Or it is just applicable for heat loss through Convection and Radiation?
0
votes
0
answers
13
views
Penetrative property of radiation
On looking upon the process of penetration of radiation. I came upon this: "If the particle has enough energy, it can deposit its energy to break the molecular bonds displacing the electrons, ...
- 49
-2
votes
1
answer
60
views
Why is $\beta$ decay a weak force interaction?
In my graduation and also in post graduation, I was told that $\beta$ decay is a weak interaction. But till date I don't know the reason as if why it is a weak interaction process. In my classes some ...
0
votes
1
answer
28
views
Should I use Ground State-Ground State (GS-GS) $Q$-value for decay heat?
I am calculating the decay heat of sample of an isotope of plutonium at a single point in time. To do so, I am using the formula
$$Q = λNE,$$
where $Q$ is the decay heat for a given sample of ...
- 1
-1
votes
1
answer
37
views
Photon radiation from condensing water
Does water vapor generate electromagnetic radiation/photons when it condenses into water droplets?
I know that gas water molecules need a condensation particle to combine into water droplets. A pair ...
13
votes
1
answer
1k
views
Is it possible to make an all natural smoke detector from Brazil nuts?
After reading about Brazil nuts, I discovered they have very high levels of radiation due to trace amounts of Ra-226 and Ra-228 and their decay products. A kilogram of the nut, for instance, gives a ...
- 389
0
votes
1
answer
164
views
Where are the Gamma rays in Beryllium-7 decay coming from? [closed]
Beryllium-7 decays via electron capture.
This gives of Neutrino and later a Auger electron/Extreme ultraviolet photon.
So where does the Gamma rays that occur 10% of time according to here come from?
- 2,850
0
votes
0
answers
28
views
Can the terms "Lambertian albedo" and "white-sky albedo" be used interchangeably?
To my knowledge the "white-sky albedo" is the surface albedo corresponding to diffuse illumination while "black-sky albedo" corresponds to the direct illumination. I am confused ...
- 21
1
vote
1
answer
105
views
How radioactive are Heisenberg cubes?
I recently went to a museum that had a $2 \times 2 \times 2$ Heisenberg cube on display. I was surprised since it’s about $5 ~\mathrm{lbs}$ of raw uranium and people were coming right up to the ...
- 21
2
votes
0
answers
30
views
Multipole radiation of a wave
I read that a sound wave (a scalar wave) produces monopole radiation, an eletromagnetic wave (a vector wave) produces dipole radiation, and a gravitational wave (a second order tensor wave) produces ...
- 534
1
vote
0
answers
56
views
Why doesn't KE of annihilation electrons necessarily have to be equal to each other?
We know that when a high energy gamma ray(E >= 1022 keV because the total energy of 1 electron at rest and 1 positron at rest is 511 keV) passes near a high Z(atomic weight) atomic nucleus ...
- 133
0
votes
1
answer
156
views
Probability of Compton & Photoelectric Effect when interacting with matter with different energies
As you can see in this link: https://www.researchgate.net/figure/With-very-low-photon-energies-the-photoelectric-effect-is-dominant-The-Compton-effect_fig4_221928565
Probability wise, the ...
- 133
0
votes
1
answer
65
views
Gamma and X-Ray Shielding with Photoelectric Effect
The photoelectric effect is most probably seen when the incoming light has lower energy than the energy needed for both Compton scattering and pair production to happen.
The probability of the ...
- 133
4
votes
3
answers
620
views
Does Bremsstrahlung happen when any of scattering take place (Compton, Rayleigh, Thomson etc.)?
The Bremsstrahlung effect happens when an electron is decelerated by changing its direction typically around a nucleus and then a photon beam is released.
We know that when a scattering happens, let's ...
- 133
1
vote
1
answer
42
views
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 ...
- 113
3
votes
1
answer
52
views
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 ...
- 33