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

y the perfected circula, shape of the emitters, convenient for
electron-beam welding and soldering.
Ion-opt'cal system :-nit
Figure 5.39 shows elements of the ion-optical system of grid
design. Grid 1 of tungsten, molybdenum, or tantalum is mounted on
frame 2 of stainless steel. One end of the grid filament is weldt:d
to the frame; the other, in order to compensate for thermal elongations
and the creation of tension, is attached to bellows 3. The
bellows must be two-layer as shown in the figure, if it is to compensate
for the tension of one filament, and one-layer if two fi!dmients
are compensated. The frames are attached to each other b. bushlr,8
4 of aluminum oxide. The bellows are not required for grids whose
design is shown in Fig. 5.40. The electrodes here are made ,in th.
form of rigid hollow tubes. Such shape allows the use of the lntetniia
cavity of the accele,'ating electrode pipe as a beam neutralizer
For this, it is covered with tungsten and has an additional heater.
An example of a plate electrode design is shown in Fig. 5.111a.
A plate with openings 1 is attached to the motor housing J. by Tieans
of a thin rigid stamped shell 2 and three insulators 3 of al.,Ziinum
oxide. Metal eleinent: are soldered to it to pro:ide reliable cnue.
andi insulator bracirg.
!.'requently the openings of the plate electrodeý are the L'.acing
spot of the i.eucrali:er; Fig. 5.4111 shows various version. of
neutralizers.
Heater unit
I-A
The simplest possib]e heater design is shown in Fig. 5. 1 1:a. On
a ceramic plate 1 are installed tungsten filamenr;s 2, fixed In
their seats by an opcn plate of beryllium oxide. The disacvarntage
of the heater is the hith heat los,.