gamma ray

Examples of gamma ray in the following topics:

• Gamma Rays

  • Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency and therefore high energy.
  • Gamma rays from radioactive decay are defined as gamma rays no matter what their energy, so that there is no lower limit to gamma energy derived from radioactive decay.
  • The distinction between X-rays and gamma rays has changed in recent decades.
  • Thus, gamma rays are now usually distinguished by their origin: X-rays are emitted by definition by electrons outside the nucleus, while gamma rays are emitted by the nucleus.
  • Identify wavelength range characteristic for gamma rays, noting their biological effects and distinguishing them from gamma rays

• Gamma Decay

  • Gamma decay is a process of emission of gamma rays that accompanies other forms of radioactive decay, such as alpha and beta decay.
  • Gamma radiation, also known as gamma rays and denoted as $\gamma$, is electromagnetic radiation of high frequency and therefore high energy.
  • Gamma rays from radioactive decay are defined as gamma rays no matter what their energy, so there is no lower limit to gamma energy derived from radioactive decay.
  • Gamma decay accompanies other forms of decay, such as alpha and beta decay; gamma rays are produced after the other types of decay occur.
  • Excited levels for Ni-60 that drop to ground state via emission of gamma rays are indicated

• Radiation

  • Gamma rays are very penetrating and are commonly used for sterilization of disposable medical equipment, such as syringes, needles, cannulas and IV sets, and food.
  • Sterilization by irradiation with gamma rays may, in some cases affect material properties.
  • Electron beams use an on-off technology and provide a much higher dosing rate than gamma or x-rays.
  • A limitation is that electron beams are less penetrating than either gamma or x-rays.
  • Irradiation with X-rays or gamma rays does not make materials radioactive.

• X-Rays

  • They are shorter in wavelength than UV rays and longer than gamma rays.
  • The distinction between X-rays and gamma rays is somewhat arbitrary.
  • The most frequent method of distinguishing between X- and gamma radiation is the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays.
  • Historically, therefore, an alternative means of distinguishing between the two types of radiation has been by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.
  • Like all electromagnetic radiation, the properties of X-rays (or gamma rays) depend only on their wavelength and polarization.

• Electromagnetic Spectrum

  • Frequencies observed in astronomy range from 2.4×1023 Hz (1 GeV gamma rays) down to the local plasma frequency of the ionized interstellar medium (~1 kHz).
  • Generally, electromagnetic radiation is classified by wavelength into radio wave, microwave, terahertz (or sub-millimeter) radiation, infrared, the visible region we perceive as light, ultraviolet, X-rays, and gamma rays.
  • Gamma rays: Energetic ejection of core electrons in heavy elements, Compton scattering (for all atomic numbers), excitation of atomic nuclei, including dissociation of nuclei.
  • High-energy gamma rays: Creation of particle-antiparticle pairs.
  • Dr Atkinson soon moved on to the un-needed gamma rays and improved them to delta rays!

• Photon Interactions and Pair Production

  • In nuclear physics, this reaction occurs when a high-energy photon (gamma rays) interacts with a nucleus.
  • The electron and positron can annihilate and produce two 0.511 MeV gamma photons.
  • If all three gamma rays, the original with its energy reduced by 1.022 MeV and the two annihilation gamma rays, are detected simultaneously, then a full energy peak is observed.

• Photon Energies of the EM Spectrum

  • He called these radiations 'X-rays' and found that they were able to travel through parts of the human body but were reflected or stopped by denser matter such as bones.
  • The last portion of the electromagnetic spectrum was filled in with the discovery of gamma rays.
  • However, in 1910, British physicist William Henry Bragg demonstrated that gamma rays are electromagnetic radiation, not particles.
  • In 1914, Ernest Rutherford (who had named them gamma rays in 1903 when he realized that they were fundamentally different from charged alpha and beta rays) and Edward Andrade measured their wavelengths, and found that gamma rays were similar to X-rays, but with shorter wavelengths and higher frequencies.
  • Generally, electromagnetic radiation is classified by wavelength into radio waves, microwaves, terahertz (or sub-millimeter) radiation, infrared, the visible region humans perceive as light, ultraviolet, X-rays, and gamma rays.

• Modes of Radioactive Decay

  • Alpha particles carry a positive charge, beta particles carry a negative charge, and gamma rays are neutral.
  • Likewise, gamma radiation and X-rays were found to be similar high-energy electromagnetic radiation.
  • Some decay reactions release energy in the form of electromagnetic waves called gamma rays.
  • However, unlike visible light, humans cannot see gamma rays, because they have a much higher frequency and energy than visible light.
  • Gamma rays can only be reduced by much more substantial mass, such as a very thick layer of lead.

• B.4 Chapter 4

  • People also generally draw the path of a light ray at 45$^\circ$.
  • The light ray bisects the angle between the $x$ and $t$ axes.
  • Kara who is travelling along $t'$ will find that the speed of light is the same for her, so the light ray must also bisect the angle between $x'$ and $t'$.
  • One model to understand how cosmic rays are accelerated is through shocks.
  • $\displaystyle u^\mu = \left [ \begin{array}{c} \gamma c \\ -\beta \gamma c \\ 0 \\ 0 \\ \end{array} \right ] ~\mathrm{and}~E'=-u_\mu p^\mu = \gamma E + \beta \gamma E \approx 2 \gamma E$

• A Complete Synchrotron Spectrum

  • $\displaystyle N(E) dE = C E^{-p} dE~\mbox {or}~N(\gamma) d\gamma = C \gamma^{-p} d\gamma$
  • $\displaystyle {N}{\gamma} = \frac{Ct \gamma_c}{p-1} \gamma^{-(p+1)} \left [ 1 - \left ( 1 - \frac{\gamma}{\gamma_c} \right)^{p-1} \right ] ~\mbox{for}~\gamma_m < \gamma< \gamma_c$
  • $\displaystyle {N}{\gamma} \approx C t \gamma^{-p} ~\mathrm{for}~ \gamma_m < \gamma \ll \gamma_c .$
  • $\displaystyle {N}{\gamma} = \frac{C t \gamma_c}{p-1} \gamma^{-(p+1)} \left [ \left (\frac{\gamma}{\gamma_m} \right )^{p-1} - \left ( 1 - \frac{\gamma}{\gamma_c} \right)^{p-1} \right ] ~\mathrm{for}~ \gamma < \gamma_m < \gamma_c .$
  • Well into the slow cooling regime we have $\gamma_m\ll \gamma_c$ so $\gamma_\mathrm{cut-off} \approx \gamma_m$.