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15. A) Open the brackets giving the right forms of the words; b) Translate the text “Cryopump” in a written form; c) Compare texts 15.1 and 15.2.

15.1. A cryopump is a vacuum pump that traps gases and vapors by (condense) them on a cold surface. They are only (effect) on selective gases, depending on the freezing and boiling points of the gas relative to the cryopump's temperature. They are sometimes (use) to block particular contaminants. In this function, they are (call) a cryotrap or cold trap, even though the physical mechanism is the same as for a cryopump. Cryopumps are commonly (cool) by dry ice or liquid nitrogen. Saturation happens very quickly in low vacuums, so cryopumps are usually only used in high or ultrahigh vacuum systems. Regeneration of a cryopump is the process of (evaporate) the trapped gases. Some cryopumps have multiple stages at various low temperatures. Cryopumps are often (combine) with sorption pumps by (coat) the cold head with highly adsorbing materials such as (activate) charcoal or a zeolite. Sorption pumps are a type of cryopump that is often used as roughing pumps to reduce pressures from the range of atmospheric to on the order of 0.1 Pa (10–3 Torr).

15.2. Look through the text 15.1 again and say if you see the difference between the English and Russian definitions of the pump.

Крионасос – это конденсационный или сорбционный насос с рабочими поверхностями, охлаждаемыми до сверхнизких температур. Действия крионасосов основано на физических явлениях, происходящих при низких температурах. Крионасосы классифици-руют по следующим признакам: принципу действия, температурному уровню криопанели, быстроте действия.

16. Grammar Tutorials: Question Technique Read and give a title to the text. Put questions to the given answers.

Vacuum pumps are used in many industrial and scientific processes including:

a) The production of most types of electric lamps, vacuum tubes, and CRTs where the device is either left evacuated or re-filled with a specific gas or gas mixture

b) Semiconductor processing, notably ion implantation and sputtering

c) Electron microscopy

d) Medical processes that require suction

e) Mass spectrometers to create an ultra high vacuum between the ion source and the detector

f) Vacuum engineering

g) Vacuum pumps are also used to produce a vacuum that may then be used to power mechanical devices. In gasoline-powered automobiles, a vacuum is produced as a side effect of the operation of the engine and the flow restriction created by the throttle plate.

h) In an aircraft, the vacuum source is often used to power gyroscopes in the various flight instruments. To prevent the complete loss of instrumentation in the event of an electrical failure, the instrument panel is deliberately designed with certain instruments powered by electricity and other instruments powered by the vacuum source.

1.----------------- No, they are used in many processes.

2.----------------- Electron microscopy, Vacuum engineering, etc.

3.----------------- To power mechanical devices.

4.----------------- As a side effect.

5.----------------- To prevent the complete loss of instrumentation.

6.----------------- No, the words “horoscope” and “gyroscope” don’t mean the same.

7.----------------- They are powered by electricity and by the vacuum source.

Additional Activities: Miscellaneous

17. Engineer Tested. What are the abbreviations? I. Па (Pa): 1.1 Public Address System, 1.2 Papa, 1.3 Pascal; II. CRT: 2.1 Cathode-ray tube, 2.2 Canadian Radio Television, 2.3 Chromium-Titanium