The x-ray tag has no wiki summary.
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Have we observed another supernova explosion since SN 2008D?
I read the wikipedia article about SN 2008D which says:
"Now that it is known what X-ray pattern to look for, the next generation of X-ray satellites is expected to find hundreds of supernovae every ...
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1answer
42 views
How are X-rays focused? Specifically in XRD. Well do they even focus X-rays in XRD?
I read in a gov website that reflecting an x-ray from a parabolic mirror followed by a reflection from a hyperbolic mirror results in focusing the x-ray, but this was for astronomical purposes. I was ...
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2answers
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Is the index of refraction dependent on the wavelength of light?
I just read in some class notes for a crystallography class that there are no refractive lenses for X-rays because the index of refraction of most materials is close to 1. Is the index of refraction ...
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1answer
47 views
Reflectance and Absorption properties of X-rays
Are there any materials that are mostly "transparent" to x-rays? Such as glass would be to the visible spectrum?
What about materials or surfaces that reflect x-rays? Does most metal reflect x-rays?
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Finding out the wavelength of Xray [closed]
A sheet of aluminum 1 mm thick reduces the intensity of a monochromatic x ray beam to 23.9% of at original value. what is the wave length of xray.
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Why, in EXAFS spectrum, does the absorption coefficient monotonically decrease with increasing photon energy?
It is common knowledge that following the absorption edge, where the photon energy equals the binding energy of a core electron, a monotonic decrease in the absorption coefficient with increasing ...
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2answers
167 views
Why possibility for X-ray to excite inner electrons higher than outer electrons?
It seems X-ray absorption spectroscopy is usually ascribed to the interation between photons and inner electrons. Does it mean inner electrons are much preferred by X-ray photons to outer electrons? ...
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1answer
64 views
1MeV ray hits a band gap of 2eV : trying to understand X-rays
I am trying to understand why radio waves pass though the human body, light does not, but X-rays still pass.
In my mind I imagine that radio waves don't supply enough energy and don't excite any ...
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3answers
337 views
What is invisible to x-rays?
Is there any physical matter which won't appear on x-ray i.e. invisible matter?
I think I learnt at university that all phsyical matter appears on x-ray and there is no matter that can be invisible. ...
3
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1answer
126 views
Why are there photographs of nuclear tests?
I was looking at old photographs of the nuclear tests on the bikini atoll. It dawned on me that you don't want to run film through airport x-rays, as it exposes the film. I've been told that a ...
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0answers
100 views
Cross section of photoelectric absorption vs Thomson scattering cross section
I am interested in more less the same issue as asked here but my question is:
Why for the low X-rays the photoelectric absorption is dominant over Thomson/Compton scattering? I am considering the ...
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2answers
155 views
Compton scattering multiple wavelengths?
The formula given for compton scattering shows that when x-ray of one specific wavelength hits carbon or some materials, emitted x-ray will be of one new specific wavelength.
However, according to ...
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1answer
548 views
Differences between X-Ray and Electron Diffraction
I would want to know what the differences between these two techniques in cristalography. I research on internet, but it is not clear to me what each one does.
When it's better to use one and not ...
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2answers
169 views
Why do we stop using optics for photons above a certain energy?
I'm reading about how the soon-to-be-launched NuSTAR is on the cutting edge of focusing x-rays, which captures 5 to 80 keV radiation by focusing them with optics that have a 10.15 meter focal length ...
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2answers
946 views
What is 2 $\theta$ in X-ray powder diffraction (XRD)?
Why are we taking 2$\theta$ instead of $\theta$ in X-ray powder diffraction (XRD). I have found the forum post 2 theta in X-ray Powder Diffraction (XRD), but there is no answer. What is the ...
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2answers
178 views
Can x-ray radiation be compared to background radiation?
I've been trying to learn about the possible effects of x-ray radiation from dental x-rays and most of the resources I come across compare the exposure to that of natural background radiation.
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1answer
110 views
What is the process called that produces characteristic X-rays?
X-rays mostly consist of bremsstrahlung and characteristic X-rays. What is the process called that gives rise to the latter (but not the former)?
I'm trying to write a sentence like "X-rays are ...
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1answer
101 views
Where does the photon's energy come from in X-ray bremsstrahlung?
In an X-ray tube, bremsstrahlung is generated by accelerating electrons toward a target metal. As a photon is emitted, something loses energy. I suppose that the target metal remains fixed and is ...
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2answers
2k views
How do metallic objects interfere with X-Rays?
During my visit to the doctors', I recollect having seen the sign which says
Please remove all metallic objects from the body before the commencement of the X-Ray
How do metallic objects ...
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1answer
222 views
Absorption / Control / Reduction of EMF radiation using passive antennae & matched load
Wanted to understand the physics behind usage of passive antennae and matched load combination, to absorb, control and reduce the Electromagnetic-Field (s.a. due to microwave radiation from cellular ...
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1answer
612 views
Where are the ice rings in X-ray crystallography located?
I threw this image of one of my protein crystal's diffraction pattern (not the greatest) on a poster, and was wondering where (what reciprocal dimension) the ice rings are located as it might be a ...
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1answer
278 views
What happens if you x-ray an x-ray?
The title largely sums up my question, what does happen if you either x-ray an x-ray, or point two x-ray generators at each other?
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Light vs. X-ray interactions with Phosphor
Looking for some information on how light and xrays interact with phosphorous, or what might cause the following:
Scenario
A focus beam of light is directed at a phosphor plate at the same time as ...
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6answers
2k views
How can a black hole emit X-rays?
Considering that a black hole's gravity prevents light from escaping, how can a black hole emit X-rays? Visible light and X-rays are both electromagnetic radiation, shouldn't the black hole's gravity ...
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2answers
181 views
Can one see radioactive substances with an X-ray detector?
I was wondering the other day an X-ray detector (like the ones used at airports) can detect gamma-rays lets say from a sample of uranium. I know its all electro-magnetic waves but I'm really unsure ...
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2answers
826 views
How does fluoroscopy (x-ray) imaging work in practice?
I know the basics, that by measuring how much x-ray signal reaches each 'pixel' on the receiver we can measure how much has been absorbed. But this gives only a single channel of information, e.g a ...
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1answer
42 views
Do XAFS excitations and subsequent relaxations lead to vibrationally hot molecules?
I'm in the process of trying to understand X-Ray Absorption Fine Structure (XAFS) spectroscopy, but I think this question is more fundamental than merely as it pertains to XAFS. I think I don't ...
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2answers
115 views
Can a multipass x-ray absorption cell be constructed?
I've been trying to understand the various concepts behind x-ray optics compared to standard visible/IR optics like mirrors and such. However, the x-ray mirrors I've been finding typically have ...
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1answer
154 views
Proton therapy in cancer treatment
Why are protons used in cancer therapy ? Is there any advantages compared to classics X-rays treatment or electron treatment ?
