How Do X-Rays Work By: Carrie Lisle

Discovery of the X-ray Original inventor- A. W. Goodspeed on February 22, 1890 Had no information or proof, didn’t take credit November 8, 1895, discovered by Wilhelm Conrad Roentgen

Discovery of the X-ray Discovered by accident Wilhelm was experimenting with electron beams in a glass discharge tube Fluorescent screen in lab glowed when electric beam was turned on Tube was surrounded by heavy black cardboard which should have blocked radiation

Discovery of the X-ray Tried putting various objects between tube and screen Put hand in front of tube, saw silhouette of bones Called “X” rays because it was an unknown type of radiation Name stuck despite friends’ suggestion for “Roentgen” rays

What is an X-ray? Eyes aren’t sensitive to higher energy level and shorter wavelengths of x-rays Both produced by movement of electrons in atoms Similar to visible light rays Both are wavelike forms of electromagnetic energy carried photons Have different energy levels

What is an X-ray? Electrons occupy different orbitals Electrons dropping to another orbital releases energy in the form of electrons in atoms Photon energy level depends on how far the electron is dropped Photon-atom collisions may cause atoms to absorb energy Photons’ energy level must match the difference between the orbitals

What is an X-ray? Atoms making up body tissue absorb visible light photons very well X-rays have too much energy, and therefore pass through most things Soft body tissue doesn’t absorb X-ray photons well Calcium atoms in bones absorb X-ray photons well

The Light Spectrum GAMMARAYSGAMMARAYS XRAYS^^^XRAYS^^^ ULTRAULTRA VIOLETVIOLET VISIBLEVISIBLE LIGHTLIGHT INFRAREDINFRARED MICROWAVESMICROWAVES RADIORADIO WAVESWAVES

The X-ray Machine Machine passes current through filament, heating it up Heat sputters electrons off filament surface Anode draws electrons across tube

The X-ray Machine Electrons fly through tube with high force Electron and tungsten atom collide Knocks one of atoms electrons loose Another electron takes empty place Releases extra energy in photon form- high energy

The X-ray Machine Atom’s nucleus can attract a speeding electron enough to change it’s course Approaching nucleus, electron slows down and changes direction as it passes the atom Slowing down causes electron to emit excess energy in X-ray photon form

The X-ray Machine High-impact collisions generate a lot of heat Rotating motor keeps anode from melting Entire mechanism is surrounded by a thick lead shield Shield keeps X-rays from escaping in all directions

The X-ray Machine A small window in the shield lets out the photons in a narrow beam Beam passes through filters on way to patient Camera on opposite side of patient records X-ray pattern X-ray cameras see chemical reactions, not visible light

The Harm of X-rays X-rays hit an atom, knocking off electrons to create an ion Ions cause unnatural chemical reactions inside cells Charge can break DNA chains Cells with broken strands of DNA will die or develop a mutation Can cause various diseases or even cancer

X-ray Radiation Only large amounts of X-rays cause radiation Can reduce cell division and damage genetic material X-ray machine users use protection Lead shields and vests

What are X-rays used for? Used in radiation treatment To look at bones To see possibly swallowed things in the body To see gunshot wounds To look at gallstones To examine teeth In crystal research

Bibliography Dugdale, David. “How X-rays Work.” February April Jacikas, Kelly and Mark Woodland. “X-Rays.” 16 October April Juhl, Katie. “How do X-rays Work.” 26 April Moncton, David E. “X-Rays.” World Book ed.

About the Author Hi! My name is Carrie Lisle. I chose to do x- rays for my project because I’ve always wondered how doctors could see to your bones and security at the airport could see what was in people’s bags.