Discovery of Radiation

Date: 2015-10-07; view: 474.

Introduction

Radiation Units

Практика 3 Unit3

In order to evaluate the hazards of radiation it is necessary to have a measure of the harm which the radiation does. When S.I. units were introduced several years ago the older units of radiation (rad and rem), were replaced with new units (gray and sievert).

Shortly after the discovery of x-rays in 1885 by Professor Roentgen, scientists began to notice the harmful effects of exposure to this radiation. It was, however, many years before people realised how dangerous x-rays and other radiation could be. Quite a number of pioneer radiologists suffered severe injuries, and some even died, as a result of prolonged exposure to dangerously high intensities of x-rays. These early workers in the field had no means of measuring the harm caused by radiation accurately and depended on unreliable effects such as the degree of skin reddening caused by the exposure, or on timing the exposure from a certain type of x-ray machine to establish quantity.