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B Glossary
The glossary contains key technical terms used throughout this manual.
Background The term background refers to the ambient radiation present around the in-
strument. The background includes Natural background and mixtures of pertur-
bation sources surrounding the measurement site. Situations may arise, where the
reduction of perturbation sources cannot be optimal, e.g. in laboratories operating
with radiation sources.
Centroid Center of a peak. The centroid is used to measure peak position. Its numerical
value is often generated by a peak fit routine. In the radEAGLET-R, a peak fit is per-
formed in the calibration screens, presenting you the centroid and resolution of the
peak.
Full-width-at-half-maximum (FWHM) There are two points of the peak which have a height
that equals half the height of the centroid position. One point on the left, another
one right of the centroid. The distance between the energies of these two points is
called the full-width-at-half-maximum abbreviated as FWHM. The FWHM divided by
the centroid energy leads to the resolution.
Geiger-Müller Detector (GM) Secondary detector onboard the radEAGLET-R. The GM de-
tector consists of a pressurized tube filled with a radiation sensitive gas. Various
gases can be used here, typically inert gases such as helium, argon, neon or xenon.
Often these are mixed with an organic vapor or a halogen gas. GM tubes detect radi-
ation utilizing an anode-cathode pair inside this gas. The cathode is the tube housing
while the anode is a small wire in the center of the chamber. Radiation ionizes the
atoms of the gas initiating a charge avalanche which drives a current towards the an-
ode which generates a count. The number of counts is proportional to the strength
of the radiation. GM detectors are non-spectroscopic.
Natural Background Natural background is the radiation around the instrument caused
by natural processes. First, there are particles and photons coming from space,
including the radiation of sun and cosmic rays. This type of natural background is
called the cosmic background. There are certain materials in the earth land masses
that are radioactive, such as uranium, thorium or potassium. This material is called
naturally occurring radioactive material or NORM).
Naturally Occurring Material (NORM) Naturally occurring materials are, e.g., potassium
40
K, thorium
state and consequently is reflected by a radium
the terrestrial background radiation.
© innoRIID GmbH • 2020-11-18
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Th and uranium ore, which by now has arrived in its radium ground
Software 3.2.12r • Document 3.3.3b4o
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Ra spectrum. NORM constitutes
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