Special protective equipment for fire fighters In confined space use self-contained breathing apparatus. Wear self-contained breathing apparatus when entering area unless atmosphere is proved to be safe. Ensure adequate air ventilation. Environmental precautions Try to stop release. Prevent from entering sewers, basements and workpits, or any place where its accumulation can be dangerous.
Clean up methods Ventilate area. Do not allow backfeed into the container. Contact your gas supplier if in doubt. Check regularly tightness of the plant. Refer to supplier's handling instructions. Storage Secure cylinders to prevent them falling. Your most recent searches Delete.
Frequent searches. Other sections. Catalog excerpts. Open the catalog to page 2. Overview of Shielding Gases 12 Pages. ETO 3 Pages. DA 2 Pages. Cl2 3 Pages. A short summary of this paper. Download Download PDF. Translate PDF. Silfvast This book is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. Includes bibliographical references and index.
ISBN 1. S52 It comes in sizes ranging from approx- of our compact disc players. They from the microwave to the soft—X-ray spectral regions act as target designators for military weapons and pro- with corresponding frequencies from to Hz. They can easily acteristics for a device that is in only its fifth decade drill holes in the most durable of materials and can of existence!
It can be thought of as just another type of light source. It certainly has many unique properties that make it a special light source, but these properties can be understood without knowledge of sophisticated mathematical techniques or complex ideas. It is the objective of this text to explain the operation of the laser in a simple, logical approach that builds from one con- cept to the next as the chapters evolve.
The concepts, as they are developed, will be applied to all classes of laser materials, so that the reader will develop a sense of the broad field of lasers while still acquiring the capability to study, design, or simply understand a specific type of laser system in detail.
The laser makes use of processes that increase or amplify light signals after those signals have been generated by other means. Thus, in its simplest form, a laser con- sists of a gain or amplifying medium where stimulated emission occurs , and a set of mirrors to feed the light back into the amplifier for continued growth of the developing beam, as seen in Figure Normally, a burning candle radiates light in all directions, and therefore illumi- nates various objects equally if they are equidistant from the candle.
A laser takes light that would normally be emitted in all directions, such as from a candle, and concentrates that light into a single direction. Thus, if the light radiating in all di- rections from a candle were concentrated into a single beam of the diameter of the pupil of your eye approximately 3 mm , and if you were standing a distance of 1 m from the candle, then the light intensity would be 1,, times as bright as the light that you normally see radiating from the candle!
That is essentially the underlying concept of the operation of a laser. However, a candle is not the kind of medium that produces amplification, and thus there are no candle lasers. It takes relatively special conditions within the laser medium for amplification to occur, but it is that capability of taking light that would normally radiate from a source in all directions — and concentrating that light into a beam traveling in a single direc- tion — that is involved in making a laser.
These special conditions, and the media within which they are produced, will be described in some detail in this book. When comparing laser properties to those of other light sources, it can be readily recognized that the values of various parameters for laser light either greatly exceed or are much more restrictive than the values for many common light sources.
We never use lasers for street illumination, or for illumination within our houses. Lasers generally have a narrower frequency distribution, or much higher intensity, or a much greater degree of collimation, or much shorter pulse duration, than that available from more common types of light sources. Therefore, we do use them in compact disc players, in supermarket check-out scanners, in surveying in- struments, and in medical applications as a surgical knife or for welding detached retinas.
We also use them in communications systems and in radar and military targeting applications, as well as many other areas. A laser is a specialized light source that should be used only when its unique properties are required. There are several types of units that are used to define laser wavelengths. This device produced a coherent beam of microwaves to be used for communications. The first maser was produced in ammonia vapor with the inversion between two energy levels that produced gain at a wavelength of 1.
The wavelengths produced in the maser were compara- ble to the dimensions of the device, so extrapolation to the optical regime — where wavelengths were five orders of magnitude smaller — was not an obvious extension of that work.
In , Townes and Schawlow published a paper concerning their ideas about extending the maser concept to optical frequencies. They developed the concept of an optical amplifier surrounded by an optical mirror resonant cavity to allow for growth of the beam. Townes and Schawlow each received a Nobel Prize for his work in this field. In , Theodore Maiman of Hughes Research Laboratories produced the first laser using a ruby crystal as the amplifier and a flashlamp as the energy source.
The helical flashlamp surrounded a rod-shaped ruby crystal, and the optical cavity was formed by coating the flattened ends of the ruby rod with a highly reflecting material. Precautionary Statement Storage 3 Store in a well-ventilated place. Contains no other components or impurities which will influence the classification of the product. Victim may not be aware of asphyxiation. Low concentrations of CO2 cause increased respiration and headache.
Remove victim to uncontaminated area wearing self contained breathing apparatus. Keep victim warm and rested. Call a doctor. Apply artificial respiration if breathing stopped. In case of frostbite spray with water for at least 15 minutes. Apply a sterile dressing. Obtain medical assistance. Ingestion Ingestion is not considered a potential route of exposure.
Non flammable. Hazardous combustion products None. Suitable extinguishing media All known extinguishants can be used. Specific methods If possible, stop flow of product. Move container away or cool with water from a protected position.
Special protective equipment for fire fighters In confined space use self-contained breathing apparatus. Wear self-contained breathing apparatus when entering area unless atmosphere is proved to be safe. Ensure adequate air ventilation.
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