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Compton Effect, why does electromagnetic radiation lose less energy when hitting particles with greater mass?

One of the problems in Rae's Quantum mechanics book, at the end of the first section, relates to x-ray's scattering off either an electron or a carbon atom. Using the equation given to you in the book ...
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1answer
45 views

publication ethics [closed]

What does it mean if somebody publishes the same concept of my paper with some changes without citing it although the paper has been published 5 years before his, and the concept was clearly first ...
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4answers
2k views

Do free-electron lasers actually lase?

Free-electron lasers are devices which use the motion of highly energetic electron beams to produce bright, coherent radiation in the x-ray regime. More specifically, they start with a high-energy ...
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2answers
46 views

Is an x-ray maser possible?

I was wondering if lasers evolved from masers. They applied the same principles to a different wavelength. Would it be possible to create a maser at a higher wavelength, using x-rays, gamma rays, ...
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0answers
38 views

How to detect transient X-ray?

I have a Mercury UV lamp (ENF-260C/FE) which is supposed to emitte UV light with wavelength of 254nm and 365nm (http://www.chescientific.com/ecat/Eng/spectroline.pdf). However it is found that during ...
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0answers
27 views

Sum rule in X-ray Photoelectron Spectroscopy (XPS)

What is the sum rule in X-ray Photoelectron Spectroscopy (XPS)? how can I derive it? Can anybody explain the principle of sum rule in XPS or in spectroscopy in general? How can I apply it to a ...
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1answer
32 views

How do atoms scatter X-rays?

I am learning the theory behind X-ray diffraction but I have a question. According to the textbook I am using, X-ray tubes (in diffractometers) produce near monochromatic X-rays. In other words, they ...
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0answers
25 views

About X-ray Dynamical Diffraction

I am studying X-ray Dynamical Diffraction. I understood that X-ray Dynamical theory is used when higher-order scattering or multiple scattering terms in the Born series become important and cannot be ...
0
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1answer
23 views

Why higher FAT level implies more signal in XPS analysis?

In XPS analysis, the FAT (Fixed Analyzer Transmission) parameter controls the electrostatic field of an emispheric analyzer, called Pass Energy $E_P$. The FWHM of a peak of signal is given by ...
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0answers
60 views

Characteristic X Ray and Intensity-Wavelength Graph

This is somewhat the kind of graph given in my book. Questions- Q.1- Why is the intensity much higher for the characteristics rays than the continous spectrum? I understand that the wavelengths ...
2
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1answer
63 views

How do we know that the x-ray pattern is in the reciprocal space? [closed]

I wonder if any one can tell that why do we consider the x-ray pattern (for example, a x-ray pattern on a film for a crystal) in the reciprocal space? (I don't want any explanation about the Ewald ...
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0answers
27 views

Process of x-ray crystallography

This is a pretty basic question but I would just like some confirmation of what I suspect is true. As I understand it, the basic idea behind x-ray crystallography is that we take our crystal and hit ...
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0answers
28 views

Law of refelction for electron-metal interactions?

I was reading 'Webb's Physics of Medical Imaging' which had a diagram very similar to the following in it: The interaction not the electrons with the anode creates x-rays. This diagram indicates ...
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0answers
33 views

Emission of Characteristic X Rays

X-rays are emitted when high velocity electrons in an X-ray tube collide with a metal target. Some high velocity electrons on collision with the metal atoms cause an inner electron of an atom to be ...
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3answers
162 views

Why we don't use gamma rays, x-rays or ultraviolet to transmit data?

The greater the frequency range of a transmission medium, the greater the number of bits per second it can transmit. In other words, the bigger the bandwidth in hertz available, the bigger the ...
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0answers
36 views

How to convert the number of X-rays to one of the radiation dose units?

So I have been struggling while trying to wrap my head around how radiation dose from X-rays work. I understand how to calculate how many X-rays would come from an X-ray tube given some settings. I ...
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1answer
44 views

Characteristic Ka X-rays [closed]

In an experiment one observes the characteristic Ka X-rays of two elements at energies of 6.930 and 7.478 eV. The higher energy line is due to Ni. What element is responsible for the lower energy ...
1
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1answer
150 views

How to find the constants in Moseley's law?

Recentely we were discussing / learning Moseley's law in class. We have successfully constructed the most basic version of it: $$f=f_R*(Z-1)^2*(1-\frac{1}{n^2})$$ with $n$ being the main quantum ...
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0answers
19 views

Determining angle of distortion in a Rhombohedral unit cell

I have a film which is rhombohedrally distorted. I would like to measure by Xray diffraction, the angle of distortion of the unit cell. I can measure the in-plane and out-of-plane lattice parameters ...
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3answers
4k views

How many X-rays does a light bulb emit?

I read somewhere that most things1 emits all kinds of radiation, just very few of some kinds. So that made me wondering whether there is a formula to calculate how many X-rays an 100W incandescent ...
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2answers
141 views

will osmium or lead stop all high-energy photons in a shorter distance?

I remember seeing a similar question to this one on Physics StackExchange once. Most of the answers were to the effect of "I don't like the way this question is phrased, so I will insult your ...
2
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1answer
27 views

Is it normal for radiation levels to be elevated near a medical imaging lab?

I work in a general-purpose, commercial office building where the first floor is dedicated to an x-ray / imaging lab for medical diagnostics. The public lobby of this building is routinely ...
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0answers
51 views

X-ray characteristic radiation

A high speed electron knocks an orbital electron in the atom. This collision creates a vacancy that is filled by an electron from a higher energy level. My question is, what happen with both electrons ...
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1answer
100 views

How are Dual-energy X-ray absorptiometry (DXA/DEXA) scans affected by surface stability?

Today I had my body scanned by a GE Lunar Prodigy densitometer installed in a small RV of a company that tours California offering body composition scans (image from Wikipedia article on DXA). ...
2
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2answers
63 views

Attenuation of X-Ray Radiation

I have a question regarding the attenuation of x-ray radiation in a Medium. Let us Assume we have a phantom like this: The darker the gray, the higher is the attenuation of x-ray radiation of the ...
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0answers
178 views

I have negative slop of Williamson-Hall plot, XRD data. Is this right?

I have Ag (silver) powder sample. I measured xdd of the sample and got very good 2theta peak. Since I want to know bulk modulus and Young's modulus of Ag(silver), So, I got williamson-Hall plot ...
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0answers
70 views

How large should an optically large fusion reactor be?

This is just theoretical consideration. I expect that size of the reactor would be impractical to build on Earth, but I'm interested how much. EDIT: perhaps it could be good for some huge spacecraft ...
0
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1answer
45 views

What is the reason that EXAFS are done with monochromatic x-ray light?

Why is the light incident on the samples in EXAFS experiments monochromatic? What would happen if a broad bandwidth hits a grating and then all the diffraction spectrum goes through the sample and is ...
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0answers
22 views

Does the EXAFS oscillations occur when ultrashort x-ray pulse is used? Electron with a 50eV kinetic energy will travel in 0.1fs 4.2 Angstroms

In X-ray extended absorption spectroscopy (EXAF) an electron is excited by an x-ray photon into the continuum, the outgoing electron wave interferes with the scattered electron wave from the ...
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0answers
7 views

How report that bragg reflection from PVC filters is greater than polypropylene filters?

I have been told that PVC filters will give a higher background in XRD analysis due to the high absorption of the Cl component. My argument is that another filter material should be used when ...
0
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1answer
52 views

X-ray background radiation

I'm running an experiment in gamma-ray imaging (although the main emission from the decay of Am-241 is ~60keV, so much more in the range of x-rays). I'm curious as to the sort of sources that would ...
0
votes
1answer
34 views

Understanding Braggs x-ray diffraction and why light is treated as a single “ray/line”

I'm not familiar with optics. So my knowledge of treating light as single lines is almost completely foreign to me. Although I do know something about EM waves and Maxwells equations, so you can ...
0
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1answer
43 views

X-ray pulse more powerful than national grid?

There is an article today in the BBC science section on the Linac Coherent Light Source, an X-ray laser in Palo Alto: http://www.bbc.com/news/science-environment-31483781. I don't trust the news with ...
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0answers
91 views

Is there a wavelength of electromagnetic radiation that can penetrate iron but reflect off iron oxides?

We can see corrosion or rust because visible light travels through air reflects off the material back through the air and into our eyes. But I am wondering if you could see the corrosion through on ...
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2answers
39 views

What is an off-axis peak in x-ray diffractometry?

I'm looking at a $\theta$ - 2$\theta$ pattern of my thin film which in bulk is cubic (bcc) and I see 001 and 002 peaks of the film. There is supposed to be a tetragonal distortion meaning that I need ...
0
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1answer
118 views

How exactly dentists X-Ray works?

At dentist, before operation I got one tooth X-Rayed. I had to hold a small tablet inside my mouth and the scanner was positioned next to my cheek. The device look like this: How does this machine ...
0
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1answer
353 views

Wavelength of X-rays in a tube

If I increase the accelerating potential in an X-ray tube the wavelength of the characteristic X-rays do not change. Is this because when an electron beam strikes the target in an X-ray tube, part of ...
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3answers
361 views

Particle-in-cell (PIC) code Virtual Laser Plasma Lab (VLPL)

I am writing a simulation code to model betatron X rays produced by electrons accelerated using laser wakefield acceleration (LWFA). I have heard about 3D PIC (Particle-in-Cell) code VLPL (Virtual ...
0
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1answer
54 views

Thomson scattering: radiation scattered in one direction or all directions?

I have a question about how Thomson scattering takes place. Say X-rays hit a bound electron in a crystal. (These electrons aren't "free", but the energy difference is so large that the scattering is ...
2
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0answers
39 views

X-rays scattered at righ angles of the incident ones: are they polarised?

Basic books dealing with the interaction of X-rays with matter ussually don't mention anything about the polarisation, but I read somewhere that X-rays scattered in matter are linearly polarized, ...
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1answer
55 views

Tape as a X-Ray Source

A couple years ago I ran upon a YouTube video demonstrating how researchers used x-rays given off by tearing tape off its spindle in hopes to miniaturized and cheapen future x-ray devices. As of ...
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0answers
37 views

What is a high brilliance X-Ray and how is one created

I just found this term being used in a Stanford Engineering year in review 2013-2014 "X-rays illuminate path to more efficient fuel cells" that cited this work. Never heard the term before and I came ...
2
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1answer
92 views

Zero Diffraction Plates: Why do they give such low diffraction signals?

In our laboratory we use silicon plates named "Zero Diffraction Plates". They are named so because they give extremely low diffraction signals in an XRD instrument (reflection mode). But how are these ...
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2answers
574 views

Why don't X-rays travel through water?

Why don't X-rays travel through water? I read that X-Rays don't travel through water, but what is the main reason? See this link:http://henke.lbl.gov/optical_constants/ it shows X-ray transmission ...
0
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3answers
217 views

Do electrons get accelerated or decelerated by the atoms of the anode during X-rays production?

The electrons striking the anode get deflected by the heavy nucleus. Though the speed may or may not change, the direction of motion changes which leads to acceleration. The charged particles emit ...
1
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1answer
42 views

Property of $Cu$ so that it is used as target in in X-ray diffraction (XRD)?

Why only $Cu$ is used as target element in X-ray diffraction (XRD)? Why not other elements? And which rays has high intensity $k_\alpha$ or $k_\beta$?
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2answers
603 views

What is the difference between xrays and ultra violet rays?

Do they differ in just frequency and wavelenght ? Or there is more about it
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2answers
96 views

Quantity to measure order in crystals

Imagine a cubic lattice for simplicity and put some atomic configuration inside of each unit cell. Lattice is of course a highly ordered entity (long range order). Please, how could I quantitatively ...
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0answers
84 views

Why does inelastic X-ray scattering probe the longitudinal dielectric function as opposed to the transverse dielectric function?

Light is a transverse wave. Therefore, light in the optical range (i.e. visible light) couples to transverse collective excitations of a material when measuring the optical conductivity for instance. ...
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2answers
1k views

How would an X-ray mirror work?

I was wondering if light can be reflected how can someone reflect X-ray of what material does it need to be made of and is its design completely different to that of our original mirrors? Does this ...