Questions tagged [x-rays]

Use this tag for question related to X-rays which are a form of high energy electromagnetic radiation having wavelength ranging from 0.1 to 10 nanometres. Also referred to as Röntgen radiation after the scientist who discovered it. X-rays have a range of application including medical CT, airport security, astronomy, crystallography, etc. Different applications use different parts of the X-ray spectrum.

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What is the input of calculating signal noise ratio (SNR) and detective quantum efficiency (DQE) in estimation of imaging system?

In its definition, the signal noise ratio (SNR) is the ratio of the mean siganl to the standard deviation of the noise. However, for a given picture what is the noise? The detective quantum efficiency ...
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Production of X-Rays for crystallography

X-Ray diffraction is an important tool for determining the crystal structure of a sample. I believe that monochromatic X-Ray beams are necessary for this kind of experiments, since diffraction ...
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How can the waves interfere in X-ray diffraction?

This is the popular diagram surrounding the Bragg's law for X ray diffraction: But what I seem to not be able to understand is when they say that the reflected waves interact constructively to create ...
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How to interpret XRD results?

I am given several datapoints of XRD strain information. It comes from XRD measurement of a thin layer (100 nm) of semiconductor deposited on top of another semiconductor. The result I'm given is ...
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What's is the energy spectrum of Xray generated by Xray tube?

The energy spectrum of Xray generated from Xray tupe looks like the shape in the following picutre. As we know the continuos spectrum is contributed from bremsstrahlung. And in the high energy ...
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Doubt about collision in characteristic x-rays

Recently I was studying characteristic x-rays and their process of emission, but I don’t understand why the ejected electron of the atom belongs always to the inner shell. Couldn’t the emitted ...
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Can X-rays travel quicker than visible light in a medium?

I have seen while reading a few books that the refractive index depends on lambda as follows by the Cauchy equation. $${\displaystyle \eta(\lambda )=A+{\frac {B}{\lambda ^{2}}}}$$ From this, the book ...
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Line Spread Function processing

I have measured signal of the x-ray detector through a slit chamber. I need to calculate MTF from it, somehow. I know, that MTF (|OTF|) is a Fourier Transform of the Line Spread Function. The question ...
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Reducing the filament voltage has no effect on the maximum photon energy produced by characteristic or Bremsstrahlung radiation. TRUE - why?

I'm studying for my radiology exams and I don't understand the answer to this question. It states that the following sentence is true: Reducing the filament voltage has no effect on the maximum ...
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Does an X-Ray tube have an electric field inside of it? [closed]

I searched the question on the web, but could not a satisfactory answer. Anyway, the question is as follows: The X-Ray tube consists of an anode, which essentially accelerates the electrons, and a ...
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Moseley's law for $K_\beta$

In a certain problem, it started out by giving a graph between $\nu$ and $Z$ .The graph resembled $y=k(x-1)^2$(the constant is unknown ,that is we only know the vertex value,not the slopes). At the ...
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Is there a formula for probability of Compton Scattering?

I am making a Monte Carlo simulation of an X-ray detector and trying to account for Compton Scattering, but cannot find anywhere a formula for the probability that Compton Scattering occurs, only that ...
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Dielectric susceptibility and scattering intensity

I am currently reading a paper about Resonant Soft X-ray Scattering and they mentioned that the resultant scattering intensity can be found from the dielectric susceptibility of the thin film, with ...
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What kind of material could be used as a diffraction grating for Xrays?

I'm trying to design a home-built X-ray fluorescence spectrometer with the following layout: Building the X-ray tube is relatively simple, however I'm uncertain what material could be used as the '...
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Why does emission spectrum happen to be visible light?

Emission spectrum are, to put it simply, light emitted by atoms. But why most of atomic emission spectrums fall in visible light or at least near visible light? Why not X-ray or gamma ray, or radio ...
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Can we define x-rays as as decelerated electrons?

HI I'm a student and i was reading up about x-ray production. I realized that after the electrons hit the metal plate( usually tungsten) x-radiation is produced. Is it that the metal ironizes and the ...
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How to calculate the energy required for imaging?

Suppose you would like to investigate atomic core structures with atomic separation $x$Å. How do you calculate the energy required for imaging? Say for an X-ray? Edit: Is it simply a matter of using ...
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Can you electrostatically charge materials with X-rays?

I am wondering if by making use of the photoelectric effect someone using for example X-rays radiation could electrostatically charge positively a dielectric like glass [1] and make it therefore ...
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How much x-rays and heat is released by a high speed electron when collided with a surface?

We know that when an electron hit a target (surface) at very high velocity (or with high acceleration),it produces x-rays and heat. So my question is how strong the x-rays and heat will be,if velocity ...
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Difference between X-ray device and linac

What is the difference between an x-ray device and a linac (for medical purposes)? In case both have to produce photons. Linac: source X-ray device: source As far as I see the major difference is, ...
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Explaining Characteristic X-rays using Bohr's theory

Using Bohr's theory, the wavelength of photon emitted (when electron moves to a lower principal quantum number) for hydrogen like atoms is inversely proportional to the square of atomic number Z. But ...
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Is there a one-to-one relation between photons and electrons in bremsstrahlung?

I think I crammed the whole question in the title: Is it correct to assume that one decelerated electron is responsible for the emission of one photon?
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Why do the oil droplets pick up electrons in Milikans Oil Drop experiment?

As I currently understand it the x-ray source ionises the air liberating electrons which then stick to the oil drops hence giving them a negative charge which Milikan utilised to acquire a value for e....
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Why don't we have x-ray emitting LEDs?

I've just learnt about how X-rays are produced in existing systems. We barrage a hunk of metal with a beam of electrons, in order to get an effective yield of 20% of the energy converted into useful X-...
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Why is the screening coefficient, $\sigma_K$, in Moseley's law only constant for high $Z$ and how can it be anything other than unity?

In trying to understand the screening coefficient, $\sigma_K$ and the limitations of Moseley's law (why only valid for high $Z$) I came across a section of this lab script I found online: Moseley’s ...
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Scattered radiation factor for diagnostic

I need the confirmation, is it if we put survey meter at 270 degree, does the reading of scattered radiation is same with 90 degree. In my opinion, the reading would be same as the distance is still ...
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Building a "stelaser" - a star-powered maser network that distributes free global electricity. Why and Why not?

I wish to design a Space Based Power platform that delivers microwave power from space. This approach has been criticized (famously by Elon Musk), because converting sunlight to electrons to ...
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How does x-ray attenuation compare to sound wave attenuation?

When it comes to medical imaging (x-ray and ultrasound specifically) there seems to be a difference between the attenuation of sound and x-rays. What I am gathering is as follows: When it comes to x-...
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What is the difference between the X-ray diffraction and neutron diffraction?

In the Kittel book, I have read that the ionic form of $\text{KCl}$ contains $\text{K}^+$ and $\text{Cl}^-$, having equal number of electrons. Looking at the statement in figure that while doing the ...
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X-Rays and UV Penetration Dichotomy Relative to Visible Light (Shorter Wavelength but opposite penetration)

My understanding was that relative to visible light, ultraviolet tends to be more strongly absorbed by materials because the higher energy photons are likely to be able to interact with the material. ...
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Why do X-ray telescopes have to be in space?

I have read this question: For x-rays the (HUP limit) Δx becomes smaller than the distances between the lattice distances of atoms and molecules, and the photon will interact only if it meets them on ...
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X-Ray data of AGN

I have downloaded spectra of a quasar from the Sloan Digital Sky Survey (SDSS), but it has data in Visible Range. I need data of same quasar in the X-Ray region and I think SDSS don't have data in the ...
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Is it possible to take long-distance X-ray images at a high resolution in Earth's atmosphere?

It's my understanding that different wavelengths of EM radiation are affected by scattering and attenuation to varying degrees. Would a camera using only X-rays be able to take a picture of something ...
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How can i shoot accelerated electron directly into the air?

I am trying to do an experiment in which I have to first accelerate the electron to 10eV and then shoot into the air directly. I need some kind of membrane which allows electron to pass and keep ...
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Differentiating between gas discharge and cathode ray

I am trying to build a cathode ray tube but my vacuum pump is a fridge compressor which sucks at achieving a good vacuum! However I am getting a cathode ray like glow inside the vacuum chamber. Now to ...
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What happens to the X-ray diffraction (XRD) pattern if we use laser as a incident beam?

In X-ray diffraction (XRD) pattern we use X-ray because it has the wavelength of the same order as that of the inter-planar separation. Now if instead of X-rays I use laser light, then how it will ...
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Computers That Can Compute in Femtoseconds

I was watching a video about LCLS 2 and they mentioned that they can shoot and record up to 1 million x-ray pulses allowing them to see chemical reactions. They said that these pulses of x-ray last ...
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How are characteristic and cut-off wavelength related to each other for a metal

Find the binding energy of an L electron in titanium if the wavelength difference between the first line of the K series and its short-wave cut-off is $\Delta \lambda=26 \;\text{pm}$. Cut-off ...
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Why does x-ray films look better when illuminated with light?

Today I got an x ray of myself and it seems that it was much easier to distinguish between bones in the x ray when the films were illuminated with light from either side from either side. What is the ...
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Why is it necessary to dissipate the heat of the anode in an X-ray tube?

I understand that in an X-ray tube electrons collide with the anode which then deflects them out of the window producing X-rays and that this anode is rotated to dissipate heat. But why is it ...
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X-rays are absorbed by bone. If the width of the bone increased in proportion to the wavelength, would bone absorb radio waves?

What I’m interested in here, are the properties of different electromagnetic waves, and the factors that cause them to be absorbed by different materials and be influenced in other ways by different ...
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Multiple X-ray Emission during Electron Capture

In an atomic environment, a $\beta$-decay process competing with positron emission is electron capture, in which the nucleus absorbs one of its cloud of atomic electrons, emitting only a neutrino. $$p+...
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Elements that do not produce X-rays [closed]

I have read that hydrogen does not produce X-rays as the energy difference between its shells is small. So if this is true what are the elements that do not produce X-rays and how was Moseley able to ...
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Is it possible that in a Coolidge tube characteristic $L_α$ X-rays are emitted but not $K_α$ X-rays?

Is it possible that in a Coolidge tube characteristic $L_α$ X-rays are emitted but not $K_α$ X-rays? Suppose the electron accelerated in the Coolidge tube knocks out the electron from the L shell ...
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Can a gamma ray or x-ray cause an isotope change of a nucleus with all its electrons stripped away?

I learned that Sodium22 atoms decay to Neon 22 by ($\beta$+) (positron) emission. Also some other radioactive elements isotopes can undergo positron emission or electron absorption with a similar ...
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Do all radioactive isotopes and compounds exhibit photoluminesce?

I have an antique item - colored in a florescent yellow, which may be comprised of radioactive pigment like Uranium Oxide or other radionuclides I haven't a Geiger counter, but I already shined a UV ...
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X-ray component of solar radiation

What wavelength of x-rays are emitted by the sun and what is the fraction of energy in solar radiation present in the form of x-rays?
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How to understand what is happening in this freshman X-ray scattering diagram?

In this Yale chemistry course I am taking on YouTube, I am stuck on something at 21:36 in the lecture. I am trying to understand the diagram Professor McBride is using to explain how X-Rays scatter ...
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Do the experimentally obtained XPS Binding energies come from different shells? or all from the same shell ($1s$ $K$-shell)?

In experimentally obtained XPS atomic Binding Energy data like on NIST; is the ionization energy always for $1s$ electron, or it differs among elements? I checked the experimental data, and other ...
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Does the Thomson scattering from a free (moving) electron differ from that of a bound (hence stationary) electron?

By definition, Thomson scattering refers to the elastic scattering in electrons. however, X-ray scientists prefer to use the term XRTS (X-Ray Thomson Scattering) to describe a board range of processes ...

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