Design and Stress Analysis of Extraterrestrial ... - The Black Vault

The ionizer unit consists of the ionizer housing 1, ionizer
heater 2, ion emitter 3, plate 4 which is soldered to the ion emitter
to protect the extracting plate from erosion. In the ionizer housing
are installed screen 5 to reduce heat losses of the housing.
The ion-optical system unit consists of an accelerating electrode
6, shaping electrode 7, neutralizing electrode 8. Each electrode
is a plate with openings, connected to the ionizer housing through
insulator 9.
The motor feed unit is designed on the basis of the electrolytic
prfnciple of dosing. The working medium (cesium) is inclosed in a
ceramic capsule 10 with heater 13 protected by screen 12. When
the capsule is heated to 700 0 K, the ceramics takes on the properties of
an ion emitter. Pt this temperature the cesium begins to evaporate
from the ceramics and under the pressure of the saturated vapor
is directed to the ionizer housing. When a potential difference is
created between the working medium and the electrode capsule 11, the
cesium flow rate can be controlled very accurately.
Repeated on-and-off switching of the motor is accomplished by
cutoff valve 17 controlled by enert gas and located in gas cylinder
114 equipped with a pressure reducer 15 and cock 16.
Power is fed to the motor electrodes and the working medium tank
of the neutralizer is heated by electrical power system 18, 19, 20,
21.
The motor operates in
a manner similar to the preceding.
The main disadvantage of these two motors is the high average
temperature, which leads to high heat losses and design complication
in order to ensure long operation. The temperatures of the ion
emitter, heater, and housing can reach t. = 1200-12500C, tH = 1700-
17500C, t = 1000 0 C.
582