EM Spectrum
Even 2022 PH 212 (Modern Physics) 1
, What is radiation?
• Radiation is energy in the form of waves or particles. Radiation which is
high enough in energy to cause ionization is called ionizing radiation. It
includes particles and rays given off by radioactive material and high-
voltage equipment. Ionizing radiation includes x-rays, gamma-rays, beta
particles, alpha particles, and neutrons.
• Without the use of monitoring equipment, humans are not
able to "find" ionizing radiation. In contrast to heat, light, odors
and noise, humans are not able to see, feel, taste, smell, or
hear ionizing radiation.
Even 2022 PH 212 (Modern Physics) 2
, What X-rays ?
X rays are the ionizing electromagnetic radiation emitted from a highly evacuated
high-voltage tube. Inner orbital electrons in the target anode are stimulated to emit x-
radiation via bombardment by a stream of electrons from a heated cathode. X-rays,
like gamma rays, are penetrating and carry enough energy to ionize atoms in their
path. Nearly identical to gamma rays, x-rays require shielding to reduce their intensity
and minimize the danger of tissue damage to personnel. Mishaps with x-rays can
cause severe radiation burns and deep tissue damage and can lead to various cancers.
X-rays were discovered in 1895 when Wilhelm Conrad Röentgen observed that a screen
coated with a barium salt fluoresced when placed near a cathode ray tube. Roentgen
concluded that a form of penetrating radiation was being emitted by the cathode ray tube
and called the unknown rays, X-rays.
W C Roentgen
experiment setup in
Universität Würzburg
Wilhelm Conrad
Röentgen
Even 2022 PH 212 (Modern Physics) 3
, X-rays
Early X-Ray Tube (1899): This tube is a specimen of
the first type of gas x-ray tube to incorporate a water-
cooled anode. The hollow anode was supplied with
water by gravity feed from a supply held in the side
bulb. This type of tube was introduced by Mueller
about 1899.
William Coolidge, in 1913 designed a tube for the production of X-rays.
Coolidge tube
Even 2022 PH 212 (Modern Physics) 4
Even 2022 PH 212 (Modern Physics) 1
, What is radiation?
• Radiation is energy in the form of waves or particles. Radiation which is
high enough in energy to cause ionization is called ionizing radiation. It
includes particles and rays given off by radioactive material and high-
voltage equipment. Ionizing radiation includes x-rays, gamma-rays, beta
particles, alpha particles, and neutrons.
• Without the use of monitoring equipment, humans are not
able to "find" ionizing radiation. In contrast to heat, light, odors
and noise, humans are not able to see, feel, taste, smell, or
hear ionizing radiation.
Even 2022 PH 212 (Modern Physics) 2
, What X-rays ?
X rays are the ionizing electromagnetic radiation emitted from a highly evacuated
high-voltage tube. Inner orbital electrons in the target anode are stimulated to emit x-
radiation via bombardment by a stream of electrons from a heated cathode. X-rays,
like gamma rays, are penetrating and carry enough energy to ionize atoms in their
path. Nearly identical to gamma rays, x-rays require shielding to reduce their intensity
and minimize the danger of tissue damage to personnel. Mishaps with x-rays can
cause severe radiation burns and deep tissue damage and can lead to various cancers.
X-rays were discovered in 1895 when Wilhelm Conrad Röentgen observed that a screen
coated with a barium salt fluoresced when placed near a cathode ray tube. Roentgen
concluded that a form of penetrating radiation was being emitted by the cathode ray tube
and called the unknown rays, X-rays.
W C Roentgen
experiment setup in
Universität Würzburg
Wilhelm Conrad
Röentgen
Even 2022 PH 212 (Modern Physics) 3
, X-rays
Early X-Ray Tube (1899): This tube is a specimen of
the first type of gas x-ray tube to incorporate a water-
cooled anode. The hollow anode was supplied with
water by gravity feed from a supply held in the side
bulb. This type of tube was introduced by Mueller
about 1899.
William Coolidge, in 1913 designed a tube for the production of X-rays.
Coolidge tube
Even 2022 PH 212 (Modern Physics) 4
