A Lucas cell is a type of
scintillation counter.
It is used to acquire a gas sample, filter out the radioactive particulates through a special filter and then count the radioactive decay. The inside of the gas chamber is coated with
ZnS(
Ag) - a chemical that emits light when struck by
alpha particles
Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produce ...
. A
photomultiplier A photomultiplier is a device that converts incident photons into an electrical signal.
Kinds of photomultiplier include:
* Photomultiplier tube, a vacuum tube converting incident photons into an electric signal. Photomultiplier tubes (PMTs for s ...
tube at the top of the chamber counts the
photons and sends the count to a data logger.
Radon measurement
A Lucas cell can be used to measure
radon gas concentrations.
Radon itself is an
inert gas
An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to ...
. Its danger lies in the fact that it undergoes
radioactive decay. The radon decay products may lodge in the lungs and bombard them with
alpha and
beta
Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labi ...
particles, thus increasing the risk of
lung cancer
Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, malign ...
.
See also
*
Geiger counter
*
Counting efficiency
References
Particle detectors
Ionising radiation detectors
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