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8. Glossary
2014-06/5.5C
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Piranha & QABrowser Reference Manual
devices such as source position, collimator opening, beam direction, door closure, filter
presence, and preventing the production or emission of radiation if the potential
for an unsafe condition is detected.
Ionization
Formation of ions by the division of molecules or by the addition or removal of electrons
from atoms or molecules.
SI unit: C, Coloumb
Ionization chamber
Ionization detector consisting of a chamber filled with a suitable gas, in which an electric
field, insufficient to induce gas multiplication, is provide for the collection at the
electrodes of charges associated with ions and the electrons produced in the sensitive
volume of the detector by ionizing radiation.
Ionization constant
For air the ionization constant W/e = 33,97 J/C. The ionization constant is used to get
the correspondence between exposure and air kerma. See Roentgen and Gray for more
information.
Ionization detector
Radiation detector based on the use of ionization in the sensitive volume of the
detector.
Irradiation time
Irradiation time is usually the time a rate of a RADIATION QUANTITY exceeds a
specified level. Irradiation time is sometimes called Exposure time.
SI unit: s, second
Kerma (K)
The sum of the initial kinetic energies of all the charged ionizing particles liberated by
uncharged ionizing particles per unit mass of a specified material. Kerma is measured in
the same unit as absorbed dose. The SI unit of kerma is joule per kilogram and its
special name is gray (Gy). Kerma can be quoted for any specified material at a point in
free space or in an absorbing medium. Typically the kerma is specified in air.
SI unit: Gy = J/kg
Kerma rate (K')
Kerma per unit time. Kerma rate is determined as the quotient of dK by dt, where dk is
the increment of kerma in the time interval dt: K'=dK/dt. A unit of kerma rate is any
quotient of the Gray or its multiples or submultiples by a suitable unit of time (Gy/s,
mGy/h, etc.).
SI unit: Gy/s = J/kg·s
Kilovolt (kV)
A unit of electrical potential difference equal to 1000 volts.
kVp
See Peak tube voltage
Lead equivalent
The thickness of lead affording the same attenuation, under specified conditions, as the
material in question.
Summary of Contents for Piranha
Page 1: ...Reference Manual English Version 5 5C Piranha QABrowser RTI article number 9629050 10 ...
Page 8: ...Introduction Chapter 1 ...
Page 12: ...Description of the Piranha Chapter 2 ...
Page 40: ...Description of the QABrowser Chapter 3 ...
Page 77: ...Measurement Principles Theory Chapter 4 ...
Page 91: ...Measurements with the Piranha System Chapter 5 ...
Page 151: ...Optional Accessories Chapter 6 ...
Page 155: ...Problems and Solutions Chapter 7 ...
Page 161: ...Glossary Chapter 8 ...
Page 181: ...Notes Piranha QABrowser Reference Manual 2014 06 5 5C Notes 177 ...