ELECTROSTATIC GENERATORS - A REVIEW

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600360110-9
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 2
• Document Creation Date: December 22, 2016
• Document Release Date: July 22, 2011
• Sequence Number: 110
• Publication Date: November 21, 1950
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/07/22 :CIA-RDP80-00809A000600360110-9
COl~rl~tN ~ ~H~
,,4TE~~AFQ~ ~ CENTRAL INTELLIGENCE AGENCY REPORlI
INFORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS CD N0.
HOW
PUBLISHED
WHERE
PUBLISHED
DATE
PUBLISHED
LANGUAGE
Scientific - Electricity
Monthly periodical
Moscow
Nov 1948
DATE OF
INFORMATION 1948
DATE D1ST. ~.~ Nov 1950
SUPPLEMENT TO
REPORT N0.
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Elektricheatvo, No ll, 1948, pp 80-81,
Ya. M. Chervonenkie
Cand Tech Sci
The following ie a digest oP an article representing mainly a
discussion of the use of compressed dielectric gases in electrostatic
generators
Interest in electrostatic energy sources has increased recently in connection
with the need in nuclear physics for high-voltage generators to obtain homogeneous
streams?of high-energy elementary particles. Van de Graaf generators, which are
capable of producing up to 10 megavolte (Mv) do with very law currents of several
ma, are?used`for this purpose. These generators are also used in high-voltage
studies and in gbtaining hard X-rays for therapy and.industriel 'roentgenography.
?In Van de Graaf generators, a fast-moving belt continuously carries electric
charges from the earth's potential to a conducting sphere insulated from the
earth.
The maximum charge density on the belt ,surface is determined mainly by the
dielectric strength of the surrounding medium and is theoretically 5.3 x 10'9
coulomb eq~cm for air at atmospheric presets^. In practice,, it is about half se
much. The speed of the belt is 20-30 m~sec. Thus, a belt 300 mm wide operating
in air can supply current loads up to 0.5 ~?
For the given current and voltage, the linear dimensions of the generator
are approximately inversely proportional to the dielectric strength of the medium,
while its volume is inversely proportional to the cube of tL?e dielectric strength.
TWO directly opposite methods can be used to increase the dielectric strength of
the medium, namely, filling the generator with gas under high pressure or using
a high vacuum inside the generator. A highly compact Van de Graaf generator
operates in air or nitrogen at 27 atm pressure. It is designed for 2 My and 0.5
ma, and has a housing diameter of 750 mm with an insulating column 600 mm high.
At atmospheric pressure, it coup put out at least 250 kv (1).
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 Sanitized Copy Approved for Release 2011/07/22 :CIA-RDP80-00809A000600360110-9
60NFIDEHTIAI.
Still more promising is the use of some other gases, in particular Freon
(CC12F2) and sulfur hexafluoride (SF6), xhose high electric strength was first
discovered in the USSR by B. M. Gokhberg (1), and is called "elegas" in the?
USSR. These two gases provide a given electrical strength with only half tae
pressure required when air is used. As studies (1, 2, ~+) made in the Lenin-
grad Physico-Technical Institute showed, elegas is slightly better than Freon
because it is chemically more stable and has considerably higher vapor tension
at room temperature.
In a compressed gas, the breakdown voltage between the electrodes is directly
proportional to d!.stance over a wide interval of distances. In a vacm+?n, how-
ever, the breakdown gradient drops from 2-3 Mv~cral~for distances ,of 1~100~~inf~~;ct~,
l00 kv~cm~?'or.distances of 50 tc 100 mm (5)?. A vacuum has uneadellefi~insul8~iag
properties, Por..moderate ?woltages but is surpassed by compressed ga`seh for'ver~y'=hY~gh
potential differences: .If fl~ture gradients 'of zhe order oP~~~~Ve$sl`1~ivfCSni~a~=~b-
rtained at.high.YOlt4ge$, electrostatic effects could b~~usedt:hOt enl,}r for^lbwy??
power un'i~s~~of:~the~typedescribed above; but also for a. newt type~oY'~powerihl ele~C=
'kxisal~,m~c~,il.nea;Lds;e., electrostatic generators and motors.
The principles of construction of electrostatic machines have been studied
by Soviet physicists and engineers since long before the war. In 1933, N? D?
Papaleksi constructed a high-voltage electrostatic generator of the parametric
type to obtain audio-frequency currents. This generator developed power above
500 w in an atmosphere of compressed air. Papaleksi pointed out that the operat-
ing conditions of electrostatic machines are particularly favorable in a high
vacuum (3). A. F. Ioffe and his students iu the Leningrad Phyaico-Technical
Institute constructed a number of do electrical generators of various types for
voltages from 700 to 900 kv. ?These machines operated in compressed gas or in
liquids with high electrical strength (2, 4).
A. Ye. Kaplyanskiy worked out the general theory of electrostatic machines
and proved that one could create, by the capacitance principle, a number of
machines similar to all types of inductive, synchronous collectors of ;:d~E and ac,
parametric, etc. He also gave methods for the calculation of high-vacuum electro-
static generators.
It is possible in principle to use electrostatic units for direct transforma-
tion of atomic energy into electrical energy without going through the stage of
transformation into heat.
1. B. M. Gokhberg, "Elegas - Electrical Gas Insulation," Elektrichestvo, No 3,
pp 15-19, 1947 ~FDB Per Abs 1T2J.
2. B. M. Gokhberg, "IIigh-Voltage DC Electrostatic Generators," ZhTF, No 3,
pp 177-198, 1940.
fit. A. F. Ioffe. "The Electrostatic Generator," ZhTF, Vol IX, No 23, pp 2071-
208@, 1939?
N. D. Papaleksi, "Parametric Generation of Alternating currents," Elek-
trichestvo, No 11, `pp 67-76, 1938,
J. G. Trump, R. J. Van de Graaf, J. Appl. Phys., Vol~XVII2, No 3, PP 327-
342,. 1947.
~O~FIDFI'!TIAl.
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