Primary Radiation; Secondary Radiation; Deep And Shallow Dose - Thermo Scientific XL2 User Manual

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Using Your Analyzer
Safely and Effectively Using Your Analyzer

Primary Radiation

Secondary Radiation

Deep and Shallow Dose

18 Niton XL2 Analyzer User's Guide
Primary radiation is radiation that is produced by the analyzer and emitted out through the
kapton measurement window. Individuals should never place any part of their body in the
primary beam path when the x-ray tube is on. There should always be a sample in contact
with the measurement window when the x-ray tube is on. The sample will absorb most of the
primary-beam radiation unless it is smaller than the instrument's measurement window or of
low atomic mass, low density, and/or very thin. Caution should be taken when analyzing
samples that are small, thin, and/or low in atomic mass or density as they may allow much
more of the primary beam to escape. In-beam primary radiation dose rates for the Niton XL2
are listed in Table 6 andTable
their location identified relative to the analyzer in
Under conditions of normal and proper use, individuals can be exposed to secondary (or
"scattered") radiation. Secondary radiation is low-level radiation that emanates from the
sample being analyzed as a result of primary beam radiation scattering in the sample or
primary beam radiation inducing fluorescent x-rays in the sample. Dose points A, A' and B in
Figure 4 are examples of where you can encounter secondary radiation. The magnitude of this
secondary radiation is sample dependent. Higher atomic mass and density samples such as
steel will emit the lowest levels as they absorb most primary and secondary radiations. Lower
atomic mass and density samples such as aluminum, wood, and especially plastic, will produce
higher levels of secondary radiation. Secondary radiation dose rates for the Niton XL2 are
listed in Table 4 and Table
common sample types over a wide range of densities.
The operator is reminded that one should never hold samples during analysis, doing so will
result in higher than necessary exposure to secondary radiation and could expose the operator
directly to the much higher primary-beam dose rates.
You will find in Table 6,
some dose points. All dose rates listed in these four Tables are deep dose unless they are
specifically identified as shallow dose. Deep dose is dose from penetrating radiation that is
delivered to both skin and underlying tissues and organs and is the type most commonly
referred to when describing external radiation hazards. Occupational deep dose is limited to a
maximum of 5 rem (50 mSv) per year in the United States and most countries internationally.
Deep dose is measured at 1.0 cm below the skin surface.
7 - or Table 10 and Table
5 - or Table 8 and Table
Table 7, Table 10, and Table
11 for the Niton XL2 GOLDD - and
Figure 4 as Dose Point C.
9 for the Niton XL2 GOLDD - for a few
11 that shallow dose rates are listed for
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