Introduction

The x-ray is one of the most used and useful inventions of all time. An x-ray makes it simple to see the interior of someone’s body without any surgery or breaking of the skin. X-rays can be very harmful. If you are exposed to too much radiation from the x-rays you can become very ill and even die.

Doctors can see many things with x-rays that you can’t see with the naked eye, such as a broken bone, a sys, or even a chipped bone. With the naked eye all you can see are small cuts such as paper cuts, large injuries such as flesh wounds, or very, very large injuries on the surface of your skin such as a ripped off limb.

Wilhelm Roentgen discovered x-rays. While studying the light produced by cathode rays, Roentgen had placed a cathode ray tube in a box in a darkened room. (A cathode ray tube is a vacuum tube in which a cathode, or negatively charged electrode, sends out a stream of electrons.) A sheet of paper coated with a barium compound happened to be near the box. Roentgen noticed that when the tube was switched on in the closed box, the paper glowed brilliantly. He concluded that some sort of ray had penetrated the box and caused the paper to glow. Because he didn't know what they were or where they came from, he called them x-rays (x for unknown). He also noticed the rays caused photographic plates, even when wrapped in paper, to darken or fog. This led him to take x-ray photographs of objects such as his hand. The photographs revealed the inner structure of the objects. The world immediately appreciated the medical miracle of x-rays. X-rays revolutionized medicine because they enabled doctors to see inside the body without surgery

X-ray radiation is a form of radiation that is potentially very dangerous. The most dangerous part of the instrument is the direct X-ray beam. So, care should always be exercised to know the exact path of the incident beam. Scattered radiation typically has such a reduced intensity that it poses a much reduced health risk to the researcher. There are several properties of X-rays that make this type of radiation particularly dangerous to use in the laboratory. A human cannot sense X-ray radiation! Some people can feel the presence of X-rays on their skin as a kind of "tingling sensation." What these people are feeling are charged air particles produced by the interaction of X-rays with air. X-ray radiation is also hazardous because it can "bounce" off surfaces and "bend" around corners.

Although X-ray instruments have the potential to be lethal when used improperly, modern analytical X-ray instruments pose no great risk to careful users. The federal and state governments carefully regulate the manufacture and use of analytical X-ray instruments. Current regulations require a variety of safety devices be built into X-ray instruments that make it very difficult for anyone to even accidentally expose himself or herself to the dangerous incident X-ray beam. The design of the instruments limits even accidental exposures to the hands, arms, and facial areas. Also, the types of radiation used in diffraction instruments (primarily Mo and Cu radiation) are considered "soft" radiation. These types of soft radiation generally will not penetrate more than 2-4 cm into the body. Accidental exposures to radiation from diffraction experiments will usually cause damage only to the skin and possibly bones of the body. Exposure of "soft" X-rays to the eyes may cause cataracts (a very thick callus over the eye which makes it very difficult to see) to form. Because of the possibility of cataracts forming, it is recommended that glasses be worn in an X-ray lab.

There are three general rules to reduce a person's exposure to any type of ionizing radiation. These rules are part of a NRC program to reduce exposure to radiation known as ALARA, As Low As Reasonably Achievable.

1. Reduce the time you are exposed to the radiation source.
2. Increase the distance between yourself and the radiation source.
3. Increase shielding between yourself and the radiation source.

Personal radiation detection devices (film or TLD badges) are generally less important to the diffraction worker than to other radiation workers. Diffraction instruments use highly contained sources that are less likely to expose the radiation badge than larger radiation sources. However, these devices often give the first warning of exposure to a radiation worker. Actual amounts of exposure can be approximated by changes in the white blood cell count before and after the suspected incident. Personnel that are modifying or aligning the instruments do not wear LD badges in labs.

As with all types of ionizing radiation, X-rays cause the most damage to rapidly growing undifferentiated cells. So, for women that are pregnant or suspect that they are pregnant, special care should be taken to protect the fetus especially during the first trimester.

A second serious hazard from the X-ray instrument is electrical shock. The X-ray generator, which is a highly regulated DC power supply, operates at voltages of 40 to 60 kV in order to achieve a large of X rays. Trained electrical engineers should only service these power supplies.

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