A voltage divider chain of resistors is usually used to place each dynode at a potential 100-200V more positive than the previous one.
12.
These reflected electrons return down the cathode ray tube toward the first dynode of the electron multiplier surrounding the electron gun which is at high potential.
13.
It may be considered a 2-dimensional parallel array of very small continuous-dynode electron multipliers, built together and powered in parallel too.
14.
In the 1930s special amplifying tubes were developed which deliberately " folded " the electron beam, by having it strike a dynode to be reflected into the anode.
15.
During one of these visits, in September 1934, RCA's Vladimir Zworykin was shown the first multiple-dynode photomultiplier, or " photoelectron multiplier ".
16.
They can be of the continuous-dynode type, and may have a curved horn-like funnel shape, or they can have discrete dynodes as in a photomultiplier.
17.
A " continuous-dynode " structure is feasible if the material of the electrodes has a high resistance so that the functions of secondary-emission and voltage-division are merged.
18.
A typical such " orbital beam hexode " was the RCA 1630, introduced in 1939 . Because the heavy electron current in such tubes damaged the dynode surface rapidly, their lifetime tended to be very short compared to conventional tubes.
19.
A sharply focused beam of electrons ( a cathode ray ) is generated by the electron gun at ground potential and accelerated by the anode ( the first dynode of the electron multiplier ) around the gun at a high positive voltage ( approx . + 1500 V ).
