X-rays Definition and 106 Threads

An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (30×1015 Hz to 30×1018 Hz) and energies in the range 124 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it X-radiation to signify an unknown type of radiation. Spellings of X-ray(s) in English include the variants x-ray(s), xray(s), and X ray(s).

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  1. gaiussheh

    I What happens to X-rays if they do not meet Bragg's law?

    Bragg's law states that it must meet ##2d\sin[\theta]=m\lambda## for diffraction to happen. I just wonder, if you have an x-ray of slightly different energy that hits the crystal plane at the same angle ##\theta##, what would happen? It certainly can't form the same diffraction pattern at the...
  2. Dante Meira

    I What travels faster: visible light in water or X-rays in liquid mercury?

    I could find some approximations in a Google search about the speed of visible light in distilled water, but couldn't find much about the speed of X-rays in liquid mercury. In which medium electromagnetic waves travel faster, distilled water or liquid mercury? Does the wavelength of the...
  3. cemtu

    I Why is bremsstrahlung radiation greater than acceleration radiation?

    Why is breaking radiation stronger than accelerating radiation? Why is it that when an electron comes accelerating toward a nucleus radiate weaker than when it goes decelerating away from the nucleus? Is it because when it decelerates, at the same time it changes direction? Or is it because it...
  4. kyphysics

    Does Radiation from X-Rays/CT Stay in Body Forever (Risks)?

    I'm slightly confused by what medical professionals/scientists say when they say to limit exposure to x-rays/CT/PET, etc. scans if possible, due to radiation. I'm also confused as to why we're often told to leave the room when a relative is getting such a scan, given that medical staff that...
  5. T

    B Exploring the Potential X-Ray Emissions of Neon Signs

    Hello guys. I'm interested about wether or not a conventional neon sign such as this one could emit xray that could be harmful. Thanks a lot :)
  6. R

    A Any electron/beta coincidence database?

    Hello All, I am aware of databases which list possible gamma-gamma coincidences for desired isotope. For example: here provides a table at the bottom with all possible gamma-gamma coincidence for Co-60. Question is, are there any similar databases/tables for electron coincidences with...
  7. K

    Can Customs X-Rays Detect Toxic Chemicals?

    Could customs x-ray security check find out if there is trace of toxic chemical left in the product? I do NOT mean illegal drug because it is supposed to be found out, but how about if there is any trace of other toxic chemicals? Could it be found out?
  8. R

    Differences between X-rays and Gamma rays

    Some people said if it is originated from electrons then it is X-ray but if it is originated from the nucleus it is Gamma ray. But people can produced X-rays and Gamma rays by Bremsstrahlung process and in Bremsstrahlung process it is resulted from decelerating or braking electrons. So, Gamma...
  9. PainterGuy

    How did Becquerel discover the connection between phosphorescence and X-rays?

    Hi, I was reading about the discovery of radioactivity and found the text quoted below important but couldn't properly understand the part in boldface. I would really appreciate if you could help me with it. Thank you. Source...
  10. hagopbul

    I Exploring Glory Phenomena in X-Rays

    Hello all: I was looking on the internet for some optical phenomena called glory , and start to wonder can we see the same phenomena in x-rays , dose this phenomena effect the x-rays impulse , not talking about Compton scattering Best H.B.
  11. A

    Obtain Cathode Ray Tubes Without X-rays

    Good Day, I would like to obtain cathode-ray tubes for deflecting electrons with a magnet. However, I don't want to deal with X-rays, and would prefer to obtain cathode tubes that cannot produce X-rays at all. I haven't had much luck on the internet finding such cathode ray tubes or I don't...
  12. Cool4Kat

    I Why are more x-rays made from metal than glass

    i know that x-rays are produced when a beam of high energy electrons hits a metal anode but why does that work better than when that same beam hits glass (like in the Crookes tube)? Thanks
  13. C

    Are x-rays from lightnings and magnetism the same effect?

    Hello! In 2010 Richard A. Lovett has published a photo from a ligthning-strike in the national geographic magazine, which shows significant x-ray radiation. Obviously a lightning-strike is an electrical current in air (and water).In electrodynamics an electrical current in metals generates...
  14. guidoeg

    Medical Xray diagnostics mutagenic and so genocide effect on genome

    They worry only about X-rays risks during pregnancy but not in pre-gravid wonen on pre-zygote oöcytes: https://www.radiologyinfo.org/en/info.cfm?pg=abdominct «Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant» But if a...
  15. G

    How can X-ray energy transitions be identified?

    Here is what I understand so far about x-ray energy transitions within an atom: The shells are divided up from lowest to highest as K, L, M, N, O, and so on. The X-ray associated with an electron dropping to a K shell is called K radiation. If the electron drops dropped from a shell directly...
  16. M

    Inverse Square Law with Half Value Layers for X-Rays

    Hello all, I have posted on Physics Forums a few times in the past, but mostly for help with my old physics classes and not anything in the real world. Part of my work involves radiography, but it is generally done in a field environment where we just shut down large sections of land to safely...
  17. B

    Vacuum / Electron Tubes and X-rays

    I've read that if you apply enough voltage to the plate of certain types of tubes, they will generate a fairly good amount of X-rays (even more so if the cathode is hot) -- I even read about a guy who managed to take relatively detailed radiographs of random objects using a standard...
  18. Asmaa Mohammad

    Target element in Coolidge tube and x-rays

    Homework Statement Homework EquationsThe Attempt at a Solution I would say that the wavelength of the characteristic spectrum will increase, but what about the bremsstrahlung spectrum? Will the cutoff wavelength will be longer?
  19. Asmaa Mohammad

    The intensity of x-rays in a Coolidge tube

    Hi, I would like to understand the factors influencing the intensity of x-rays in Coolidge tube. One factor would be the intensity of current in the tube, e.g., the number of electrons emitted by the cathode (the filament), I have no problem with that factor. But I read that another factor is...
  20. Asmaa Mohammad

    Calculation of the least value of PD needed to produce x-rays

    Homework Statement [/B] In my excercise book, I was given a typical diagram as that in Fig (6-7) above. And the problem statement says: The diagram presents the x-ray spectrum produced by Coolidge tube. Determine the least potential difference needed to produce the characteristic radiation...
  21. Arup Biswas

    How exactly are X-Rays produced?

    I found that in a cathode ray tube accelerated Electrons produce X rays! Now it can be in 3 ways 1) When the electrons are being accelerated by increasing Voltage...then according classical theoy they should radiate energy! It may be the X ray 2) When it reaches the metal plate there will be...
  22. Bloopy

    Effect of Change of Potential difference applied to an X-Ray tube

    I am a high school student, so I know only the basics of X-Rays.I simply know about continuous X-rays, cutoff wavelength and threshold wavelength. Now if I increase the potential applied to the X-ray tube, I am certain that the minimum wavelength of emitted radiation decreases. (I say this using...
  23. wolram

    B Unsolved Mystery: Where Do These X-Rays Come From?

    Has anyone an idea where these X rays come from? https://www.sciencedaily.com/releases/2016/09/160926104700.htm From Science daily, Space is filled with types of light we can't see -- from infrared signals released by hot stars and galaxies, to the cosmic microwave background. Some of this...
  24. P

    Understanding X-ray Emission: Unraveling the Confusion

    Homework Statement Although not a computational problem, I still have difficulties understanding emission of characteristic X-rays. Can someone please clear up my confusions about the topic? Here's where I'm stuck, with two texts as an example: Source for the above...
  25. Dr Wu

    X-rays produced by Solar Flares/CMEs

    Poster's warning: this will be the second time I've touched upon the subject of solar flares here in Physics Forums, for which I offer my apologies. Nevertheless, I seek clarification about the likely effects of what a seriously powerful flare (or CME) would have, either upon an astronaut in...
  26. A

    I X-ray spectra- bremsstrahlung and characteristic x-rays

    Hi all, In an x-ray spectrum, the curve part represents the bremsstrahlung part, and the spikes are the characteristics x-rays. Characteristic x-rays represent a discrete energy. However, in many textbooks, I noticed that the characteristic x-rays are often represented as a peak, which implies...
  27. B

    Does increasing kVp in x-ray production increase the number of x-ray photons?

    Why does increasing the kVp in x-ray production increase the number of x-ray photons if the number of electrons produced by the cathode is unchanged? thanks
  28. Plat

    Geiger counter and low-energy x-rays

    I have a geiger counter, the specifications say it is sensitive to x-rays down to 30kev. I wonder where that number comes from? Am I correct in thinking that any x-ray photon that enters the geiger tube will register a count, regardless of it's energy? Perhaps the 30kev minimum is there to...
  29. N

    Do X-rays' wavelength or frequency help them not excite electons....

    ... to transmit through opaque objects.? So when it comes to bone the x-rays cannot pass through them, or the steel plate because, the energy is higher, and or those bones, and steel plate have more electrons in their shells, and so is it the more electrons that absorb the X-rays, or is it the...
  30. wolram

    My 5-Day Hospital Adventure - Surviving Cold Sprays and X-Rays!

    So i spent 5 day in hospital, apart from three occasions every thing went well i elected to go for an epidural, and o boy, they sprayed my back with something that was colder than the arctic, it was a real pain full cold:mad:. After the operation i laid in bed with no feeling from my waist down...
  31. Matejxx1

    X-ray graph (characteristic X-rays)

    Homework Statement 4. On which graph are the characteristic X-rays being portrayed correctly. Homework Equations The Attempt at a Solution ok I know that characteristic X-rays happen because the electrons in outer shells move to the lowest possible energy shell and that the change in...
  32. J

    Which Element Produces Lower Energy Ka X-rays in an Experiment?

    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 line?
  33. U

    What are the quantum numbers (n, L, J)?

    Homework Statement [/B] I'm supposed to find the quantum numbers (n, L, J) for the first 3 energy levels in Iridium (Z=77), given that the first 4 ionization energies are ##76.1, 13.4, 12.8, 11.2 keV##. Homework EquationsThe Attempt at a Solution I know that the electronic configuration is...
  34. P

    What Are the Excitation Energies in a Sn Atom?

    Good morning everybody, here's a problem about excitations energy of the core level of a Sn atom. It says to construct the scheme of the core levels of Sn indicating the excitations energies. Now the K edge (the problem doesn't say we are necessarily talking about X-rays, but I think we are...
  35. A

    Have you read any other books about crystallography?

    Hi! I don't know if this question has been asked before, but I searched the forum but didn't get answer.Do you know another good book about crystallography?Thanks!
  36. G

    Scattering of X-rays and polarization

    I read once (I don't remember exactly where) that X-rays scattered perpendicularly to the direction of the incident X-rays are linearly polarized (even although the incident ones are not). I think the discussion was in the context of low energy X-rays, and the explanation used classical...
  37. Y

    Can Light Be Stretched in a Lab? Exploring Doppler Shift & X-Rays

    Is it possible to create a doppler shift of EM radiation in a lab? or is it only feasible on universal scales? I was just thinking that high energy x-rays have a sub-atomic wavelength,could these be transformed to visible light to let us 'see' an atom?
  38. N

    Why can't X-Rays travel through water?

    I read that X-Rays cannot travel through water and I wanted to understand why. What happens when X-Rays and water molecules interact that prohibit X-rays from traveling within water?
  39. EinsteinKreuz

    Can Intense X-Rays Cause Non-Stochastic Damage to Biological Structures?

    I'd like to know some specifics about the biological effects of X-rays on living tissue. I am aware that X-rays, along with other forms of ionizing radiation, have stochastic effects of DNA but what is the data regarding the non-stochastic effects of intense X-rays? In particular, can sufficient...
  40. Entanglement

    Soft X-Rays: Causes & Energy Rates

    what is the reason of soft x-rays, Is it because when a accelerated electron approaches an atom the electrons' electric field repel the incoming electron causing deceleration and also i scattering could be a reason when the electron approaches the nucleus, is that correct? what is the relation...
  41. U

    Silver Atom X-Ray Spectra: Kα & L X-Rays?

    Homework Statement For a silver atom, energy corresponding to Kα transition is 21.75 KeV. Also minimum energy of a striking electron so as to produce L X-Rays is 3.56 keV. Now, if electron with an energy of 23 keV strike a silver target the characteristic X-rays spectrum will have a)only kα...
  42. N

    Why are X-rays scattered by matter?

    Why are X-rays scattered by matter..? 1 Why are X-rays scattered by atoms in a material, though their frequencies are too high and for most of the atoms,electron clouds cannot respond to such a high frequency(that is before the electron cloud can reorient in the direction of electric field of...
  43. A

    Characteristic X-Rays and Energy Bands in Solids

    Hi there, I'm an instructor teaching a Physics course for Radiography students designed for students with little to no Physics background. In prepping the course, I've come up with a couple of questions that are bothering me and hope someone here can be of assistance. My questions pertain to...
  44. D

    Describe results of performing young's experiment with x-rays .

    describe results of performing young's experiment with x-rays and then high speed electronics. my answer: The wave particle duality is established by using his experiment. Can someone help me to add on? thnx :)
  45. I

    Thickness of lead required for 200 keV x-rays?

    is this correct? mass attenuation coeff. = 8.636 cm^2/g 8.636 * (density of lead: 11.3 g/cm^3) = 975.868 per cm thickness (mm): t= 9.21 / 975.868 = 0.009 cm = 0.09 mm
  46. C

    What Causes Scattering in Optics and How Does it Apply to X-rays?

    You can put a diffuser in front of a visual light source (i.e. lightbulb) that will scatter light in all directions. In effect, the diffuser acts as an analog lightsource by making light go in all directions (some of the enegry will be absorbed). LCD screens use diffusers to spread out their...
  47. G

    Compton Shift and energy of scattered x-rays

    X-rays with a wavelength of 0.2x10^-9 m collide with a target. The scattered X-rays experience a Compton shift of 0.0007x10^-9 m. What is the energy of the scattered X-rays?Just wondering what equations I would use here etc? Any help would be much appreciated, thanks.
  48. P

    3D Recipricol Space Mapping of Nanowires by using x-rays

    Hey I have a x-ray setup as in the figure, where alpha is the angles between the incoming x-ray beam and the sample. The x-ray are scattered, and measured by a 2D detector in the two outgoing angles. From this i will get a "slice" of the 3D recipricol map. If a want a 3D map, i think i will get...
  49. R

    Can the EM Spectrum Be Converted to Electricity Using Transformer Coils?

    The EM field of a magnet or electromagnet can be converted to electricity with the use of a transformer (coil). My question is... Does that hold up for the whole EM spectrum... IR through Gamma?
  50. C

    Confusion about Wave / Particle Behaviour of X-Rays

    Greetings, I am a Physics instructor teaching a course on Physics for Medical Radiologists and have a question to further my own understanding of wave / particle behaviour of X-Rays as used in x-ray image production. My background is more in climate / geophysics. The textbooks available for...
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