Users Manual Part 7

IBA | H-10 | Clinical User’s Guide
Volume 1 - Treatment Session
Glossary of Terms
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Ionization
The interaction of radiation (UV, X-ray, etc.) with atoms can result in the loss of
electrons by the atom. The atom becomes a charged ion.
Ionization Chamber (IC)
One of the three ionization chambers included in the PTS. See also: Ionization
Chamber no. 1, Ionization Chambers n. 2 & no. 3.
Ionization Chamber no. 1 (IC1)
Located downstream from the 135ºquadrupole magnet on each gantry. Serves as a
beam-centering monitor and a reference for the intensity of the unscattered beam.
See also: Ionization Chamber.
Ionization Chambers no. 2 & no. 3 (IC2 & IC3)
Located downstream from the variable collimator (Y-jaws). Measures the profile and
position of the beam in the “X” direction and as a dosimetry monitor for the
dosimetry channel. Also used to measure the profile and position of the beam in the
“Y” direction. See also: Ionization Chamber.
Ionization Chamber Electronic Unit (ICEU)
Located on the rotating catwalk of the gantry. An electronic device that interfaces
with an ionization chamber. See also: Ionization Chamber.
Ionization Point
The potential required to ionize the gas of a gas-filled tube. Sometimes called firing
tube.
Kilovolt (kV)
A unit of electrical power equal to one thousand volts. See also: Ampere, Kilowatt.
Kilowatt (kW)
A unit of electrical power equal to one thousand watts. See also: Ampere, Kilovolt.
Light Emitting Diode (LED)
A semiconductor diode that emits light when voltage is applied.
Linear
Having an output that varies in direct proportion to the input.
Liquid Crystal Display (LCD)
A device for alphanumeric and graphical displays using a liquid crystal typically sealed
between two pieces of glass and polarizers and activated by an external light source.