The X-rays are electromagnetic radiation, not visible to the human eye, which is able to pass through opaque bodies and to print photographic films. The great application for which X-rays are known is the X-rays of our bones that we can obtain with them. In addition, X-rays are used in a number of other applications, which you can see below.
Index
ELECTROMAGNETIC SPECTRUM
In this image you can see where the X-rays are located in the electromagnetic spectrumThe wavelength is shorter than ultraviolet rays and longer than gamma rays.
ORIGIN OF X-RAYS. DISCOVERY
The X-rays are sometimes also known as Röntgen rays. Röntgen discovered X-rays in 1895 while experimenting with fluorescence. The moment when X-rays were discovered was a very important moment in science. It coincided with the discovery of radium by the Curies and the radioactivity by Becquerel. They were all colleagues and each milestone was closely linked to the other.
WHERE X-RAYS COME FROM. HOW TO GENERATE THEM
The X-rays are produced inside a glass tube, in which a high vacuum has been built up, and where a potential difference of approximately 50 to 150 KV is applied between their positive and negative poles. The cathode is heated and electrons are emitted by the thermionic effect. These electrons travel through the empty tube until they reach the anode, where collisions occur.
Some of these collisions cause the promotion of some cortical electrons to higher layers, which upon falling back to their initial orbits emit EM energy, characteristic X-rays, whose frequency and energy (E=hv) are determined by the anode material.
APPLICATIONS OF RÖNTGEN RAYS
- Medicine - The applications in medicine are well known through X-rays and the evolution to 3D imaging that X-rays allow.
- Security - In airports, banks, X-rays are used for metal detection.
- Engineering and architecture - For checking defects in turbines, pipes and walls and almost any structural element.
- X-ray crystallography - It is an experimental technique for the study and analysis of materials, based on the phenomenon of X-ray diffraction by solids in a crystalline state.
- X-ray fluorescence - Used for elemental analysis and chemical analysis, particularly in the investigation of metals, glass, ceramics and building materials, as well as in geochemistry, forensic science and archaeology.
HEALTH EFFECTS OF X-RAYS
We copy the full WHO text on health effects. Read full text. X-rays are ionising rays:
"The damage caused by radiation to organs and tissues depends on the dose received, or absorbed dose, which is expressed in a unit called gray (Gy). The damage that an absorbed dose can produce depends on the type of radiation and the sensitivity of the different organs and tissues.
The effective dose is used to measure ionising radiation in terms of its potential to cause harm. The unit of measurement is the sievert (Sv), which takes into account the type of radiation and the sensitivity of organs and tissues.
It is a way of measuring ionising radiation in terms of its potential to cause harm. The sievert takes into account the type of radiation and the sensitivity of tissues and organs. The sievert is a very large unit, so it is more practical to use smaller units, such as the millisievert (mSv) or microsievert (μSv). There are 1000 μSv in 1 mSv, and 1000 mSv in 1 Sv. As well as being used to measure the amount of radiation (dose), it is also useful to express the rate at which this dose is delivered (dose rate), for example in microsievert per hour (μSv/hour) or millisievert per year (mSv/year).
If the radiation dose is low or exposure takes place over a prolonged period (low dose rate), the risk is considerably lower because damage is more likely to be repaired. However, there is still a risk of long-term effects, such as cancer, which may take years or even decades to appear. Such effects do not always occur, but the likelihood of their occurrence is proportional to the radiation dose. The risk is higher for children and adolescents, as they are much more sensitive to radiation than adults.
Epidemiological studies in radiation-exposed populations, such as atomic bomb survivors or patients undergoing radiotherapy, have shown a significant increase in cancer risk at doses above 100 mSv. More recent epidemiological studies in patients exposed for medical reasons during childhood (paediatric CT) indicate that the risk of cancer may increase even at lower doses (between 50 and 100 mSv).
Ionising radiation can cause brain damage to the foetus following acute prenatal exposure to doses in excess of 100 mSv between 8 and 15 weeks gestation and 200 mSv between 16 and 25 weeks. Human studies have shown no risk to foetal brain development with radiation exposure before 8 weeks or after 25 weeks. Epidemiological studies indicate that the risk of cancer following fetal radiation exposure is similar to the risk following exposure in early childhood."