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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3answers
2k views

Nuclear decay triggers

I am not a physicist but I have been wondering about this: I understand that the decay of a nucleus is a random event and one cannot predict exactly when it will happen for a particular nucleus. ...
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How much energy, momentum, and/or angular momentum are lost to radiation in Rutherford scattering?

Inspired by this question: Consider two charged particles, of masses $m_1$ & $m_2$ and charges $q_1$ and $q_2$. They approach each other from a great distance, interact via their electromagnetic ...
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Effect of volumetric flow rate on convection and radiation heat fluxes

Say we have two hot objects of the same material but of different width and same thickness. The objects are moving horizontally, have initially the same temperature and are cooled by a gas blown from ...
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1answer
36 views

Radiation levels per hour [closed]

I am trying to understand radiation levels. I have found that where I live the radiation levels go up to 100-120 nsv / hour. Does that mean that to find the daily radiation, I would need to multiply ...
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22 views

What about X-ray production supports the particle nature of light?

Apparently the production of X-rays supports the particle nature of light, but how?
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31 views

Synchrotron radiation for protons

I know that due to the huge mass difference and dependence of radiated energy on mass, protons lose much less energy in synchrotrons than electrons. Can someone tell me how to calculate the energy ...
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1answer
35 views

When does an oscillating charged particle stop radiating? (classic case)

Although self-force is one of the major problem in physics, I think with a few assumptions it's possible to deal with it, at least in Newtonian mechanics. Let's consider a periodic motion, where we ...
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1answer
23 views

Working out the radial arc of a magnetic field to get mass of electron

We have an experimental setup as below, the magnetic field strength, Bq/30s, and distances (magnet distance, Geiger counter height, Geiger to magnet centre distance) have all been recorded. The energy ...
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1answer
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Shouldn't the remaining photon energy be transferred to both electron and ion in a photoionisation?

I'm studying photoionisation and photodissociation, and I'm having a hard time trying know the microscopic details of such processes. I've read that in a photoionisation the photon is absorbed by a ...
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From where does the radiation come from in an inverse-Bremsstrahlung process?

I'm trying to know more about Bremsstrahlung and inverse-Bremsstrahlung processes. If you know any good references that treat theses topics with a good mathematical and physical basis, please let me ...
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Software for calculating particle irradiation (electrons/protons) induced desorption

I would like to calculate the sputtering rates of different materials when irradiated with charged particles, can someone recommend a good software for doing this.
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What kind of surfaces can scatter alpha particles? In general, what are the requisites for scattering alpha particle?

What are the properties needed to be possessed by material in order to scatter alpha particles?
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Threshold energy of Ti-48 inverse beta decay

Goal: Use anti neutrinos to convert Ti-48 to Ca-48 using inverse beta decay (IBD). The resulting Ca-48 should have the same half-life as natural Ca-48. Question: What is the threshold energy for the ...
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What are all the types of radiation emitting from the Earth or an arbitrary mass in space?

I'm interested in what forces collectively act upon a body in space (obviously radially, so they usually cancel) due to pressures caused by emitted radiation (of any type, strength, "size"). Can you ...
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Do all (most) frequencies of UV cause sunburn?

I recently read in a book called “The universe in your hand” that the reason you can get hurt by ionizing radiation is that the photons carry enough energy to ionize an atom, which can cause chemical ...
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1answer
34 views

How to express the $Q$-value for alpha decay in terms of binding energy of the relevant species?

I have 2 questions regarding the solution to the following question: The solution states that: Mathematically, I understand how the end result $$Q=BE\left({}^{A-4}_{Z-2}\mathrm{Y}\right)+...
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1answer
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Interstellar medium shock heating

How fast would a hypothetical spacecraft need to get to experience significant heating from interaction with the interstellar medium (ISM)? Significant, in this context, means a steady-state ...
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Why gravitational waves can only be generated by a time-varying quadrupole moment of the mass distribution?

The (rather old) source I dispose of "Sexl, Urbantke : Gravitation and Cosmology" describes the radiation of gravitational waves only rather sketchy. So why gravitational waves are only generated by ...
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1answer
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How to Clearly Define Sample Size in Half-Life Measurements?

I'm curious about how to clearly define the sample size when calculating the half-life of particles. My understanding is that the half life is statistical in nature and that for very small samples, ...
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2answers
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How do ionizing and non-ionizing radiation interact with each other?

Given an ionizing radiation $ X $ and given non-ionizing radiation $ Y $, how does this radiation 2 interact with each other? For example I have X-rays (ionizing radiations) and Microwaves (non-...
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Is there any published ratio between the photo peak and the compton continuum as seen on NaI(Tl) 3“x3” at 1460 keV?

As I know from Gamma spectroscopy, there should be a photo peak from a given element that emits a gamma ray, with the possibility of single/double escape, back scatter peak if the energy surpasses the ...
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1answer
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Why are helium nuclei, electrons and gamma radiation given special names?

Wikipedia article on alpha radiation says Alpha particles were first described in the investigations of radioactivity by Ernest Rutherford in 1899 I can't access the paper containing this ...
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Is there a radiation equivalent in the strong and weak forces?

I know that light is electromagnetic radiation (sourced by accelerating charge) and gravitational waves are gravitational radiation (sourced by accelerating mass). Is there equivalent radiation for ...
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Can beta rays induce radioactivity

I am aware that alpha particle can induce radioactivity. Is it also true for beta and gamma rays?
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Is Inverse Beta Decay a way to “undo” beta decay?

If we consider the beta-minus decay of a radioisotope, we produce an electron and an antineutrino, and a neutron which is converted to a proton. Say we take this same isotope and shoot an ...
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1answer
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Neutron capture calculation

So, the problem state is: Neutron beam radiates sample A with initial number of atoms $N_0$. With neutron capture nuclei (cores) of A are transitioning to nuclei B (they are just one neutron richer ...
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What if there was no baryon-antibaryon asymmetry in our universe?

We know that the universe goes through different evolutionary phases: radiation, matter and later dark energy epoch. What would happen if there was no baryon-antibaryon asymmetry? How would the ...
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How can beta plus decay be possible?

$\beta +$ decay is where a proton gets turned into a neutron and a positron and a neutrino. However, a neutron is heavier than a proton, so obviously this reaction is endothermic. So then, why does ...
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How 'bright' would a lethal dose of radiation be?

I watched the Chernobyl TV series with my family and my mom and brother seemed to have a hard time understanding how radiation works, and thought the show was overstating its effects. It can be hard ...
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1answer
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Ionizing Radiation Interaction with Air

Asking this question purely out of interest. I have no background in this topic. In modern radiation therapy, there's air in between the treatment machine head and the patient. With the high levels ...
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1answer
80 views

Trinity vs Nagasaki

From what I read the radiation levels in Nagasaki today are equivalent to the natural background radiation levels in the surrounding areas. On the other hand, the radiation levels at the Trinity test ...
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Radiation of a charged particle [closed]

Take a uncharged particle. It hits a resting charged particle. Will the charged particle radiate then?
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How does the inverse-square law work?

I'm trying to calculated the intensity of a source that I have done some experiments on using inverse-square law. $\begin{equation} I(r)=\frac{A \cdot E}{4\cdot \pi \cdot r^2} \end{equation}$ But I'...
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216 views

Comparing radiation levels - Chernobyl vs Moon

How radiation from Chernobyl disaster compares to cosmic radiation on the surface of the Moon (effect on human cells and electronic devices)? Why Chernobyl liquidators suffered heavily from ...
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1answer
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Why is the graphite moderator in a nuclear reactor radioactive?

Some nuclear reactors (like the RBMK in Chernobyl) use graphite as a neutron moderator. As far as I understand, this graphite material, either in rods or as blocks with embedded channels, surrounds ...
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Radiation that passes through aluminum foil for functional neuroimaging?

As a thought experiment, what kind of radiation could be used to perform functional neuroimaging in theory even if the person's head is covered in aluminum foil? To make things interesting, let's say ...
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5answers
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How does an ordinary object become radioactive?

In the 2019 miniseries "Chernobyl", ordinary objects are depicted as being capable of becoming radioactive, such as clothes, water, stones. How exactly does something composed of a non-radioactive ...
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Poisson-Regression for finding the half-time

I was given 10 data-points of time and the number of decays. I linearized them (by looking at $ln(A(t))$ where $A(t)$ is the number of decays) and wanted to compare linear regression, weightened ...
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2answers
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What does a reading of $12000$ Roentgen mean?

In the HBO series Chernobyl they frequently cite Roentgen readings, such as the 3.6 maximum reading on their initial dosimeters, the 15,000 on the meter on the front of the truck driven as close as ...
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1answer
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Irradiated Film Negatives from Chernobyl

The images attached are taken during the cleanup at Chernobyl. The white "streaks" at the bottom of each picture are said to be from intense radiation striking the film negatives, which makes sense (...
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5answers
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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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1answer
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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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1answer
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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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0answers
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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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1answer
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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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2answers
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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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1answer
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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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2answers
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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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1answer
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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, ...