Radiation comes in two forms: ionizing and non-ionizing. Ionizing radiation is emitted from radioactive atoms and can damage body tissues. It includes alpha particles, beta particles, and gamma rays. Alpha particles have a strong charge but short range, beta particles can penetrate farther, and gamma rays are electromagnetic waves that require dense materials to stop them. Exposure to high levels of radiation can cause both deterministic effects like burns and radiation sickness above a threshold dose, as well as stochastic effects like increased cancer risk related to cumulative exposure levels over time. Detection instruments like Geiger counters use ionization of gas to detect radiation.

1. Student: Pădureanu Emilian
Grade: XI C
Coord. teacher: Neagoe Loredana

2. Radiation is everywhere in nature. It
may be non-ionizing radiation (eg, radio
waves, light, microwaves) or ionizing
radiation (eg X-rays used for medical
diagnostic purposes, gamma rays used
for therapeutic purposes).

3. Ionizing radiation is emitted by
radioactive atoms. In order to be
understood, it is useful to know the
structure of the atom. An atom consists
of a nucleus (positively charged)
around which electrons orbit
(negatively charged). Normally, the
number of positive charges in the
nucleus (protons) is equal to the
number of electrons around the nucleus
and the atom is neutral from electric
point of view. If an electron is expelled
from the orbit of the atom, a free
negative electron and a positively
charged ion result.

4. Alpha Radiation. The alpha particles (α)
consist of two neutrons (no electric charge)
and two protons (positively charged).
When alpha particles cross a solid non-
material, they interact with many atoms on
a foartistic distance. They give birth to ions
and make all the energy on the short time.
Most alpha particles will consume all the
energy when they cross a simple sheet of
paper.

5. Beta Radiation. (β) Beta is a free electron.
It penetrates the solid material over a longer
distance than the alpha particle. The health
effects are mainly manifested when beta-
emitters are ingested or inhaled.

6. The gamma radiation (gamma ray) is in the
form of electromagnetic waves or photons
emitted from the nucleus of an atom. They can
completely cross the human body and can only
be stopped by a concrete wall or a 15 cm thick
lead plate. The gamma radiance is stopped by:
water, concrete and, in particular, dense
materials such as uranium and lead, which are
used as protection against exposure to this type
of radiation.

7. A typical tool for detecting radiation is the
Geiger-Muller tube. This is a glass (or
metal) tube that contains a low pressure
gas and two electrodes. When passing
through the tube of ionizing radiation, the
gas from it is ionized, causing a discharge
between the two electrodes - an electric
pulse.

8. Exposure to high levels of radiation can cause:
Deterministic effects, which are
short-term biological effects
, which usually occur after a specific incident (reddening
and / or burning of the skin, radiation illness). These
effects only occur if a threshold dose level is reached.
Symptoms occur the sooner the more severe it gets, the
higher the radiation dose.
Stochastic effects, which are delayed biological effects,
whose probability of occurrence depends on the total
dose received and the usual use after a period of time
(several years or even decades) after a cumulative incident
or exposure. These are manifested by increased risk of
cancer and hereditary illness.

9. The principles for avoiding the radiation dose are: time, distance and shielding. Therefore,
countermeasures that the public and workers have to take must be designed to:
minimize
exposure time
increase the
distance from
the radioactive
source
to shield the
person from
the
radioactive
source

10. http://www.agentianucleara.ro/article-
instrumente-de-masura-a-radiatiilor-1182.html
https://www.scribd.com/doc/39665898/Radiat
ii-Nucleare