3B Scientific Teltron Electron Diffraction Tube S - Manual

3B SCIENTIFIC® PHYSICS
1
Electron Diffraction Tube S 1013889
Instruction sheet
12/12 ALF
1 2 3 4 5 6 7 8
1 Guide pin
2 Connection pins
3 Cathode
4 Heater filament
5 Anode
6 Focusing electrode
7 Polycrystalline graphite
grating
8 Fluorescent screen
1. Safety instructions
Hot cathode tubes are thin-walled, highly evacu-
ated glass tubes. Treat them carefully as there
is a risk of implosion.
• Do not subject the tube to mechanical
stresses.
• Do not subject the connection leads to any
tension.
• The tube only may be used with tube holder S
(1014525).
If voltage or current is too high or the cathode is
at the wrong temperature, it can lead to the tube
becoming destroyed.
• Do not exceed the stated operating parameters.
• Only use safety experiment leads for con-
necting circuits.
• Only change circuit with power supply equip-
ment switched off.
• Only exchange tubes with power supply
equipment switched off.
When the tube is in operation, the stock of the
tube may get hot.
• If necessary, allow the tube to cool before
dismantling.
The compliance with the EC directive on elec-
tromagnetic compatibility is only guaranteed
when using the recommended power supplies.
2. Description
The electron diffraction tube illustrates the wave
nature of electrons by allowing observation of
interference caused by a beam of electrons
passing through a polycrystalline graphite target
on a fluorescent screen (Debye-Scherrer diffrac-
tion). The wavelength of the electrons can be
calculated for various anode voltages from the
radius of the diffracted rings and the distance
between the crystal layers in the graphite. The
tube also confirms the de Broglie hypothesis.
The electron diffraction tube is a highly evacu-
ated tube with an electron gun consisting of a
pure tungsten heater filament (4) and a cylindri-
cal anode (5) all contained in a clear glass bulb.
The electrons emitted by the heated cathode are
constrained to a narrow beam by an aperture
and are then focussed by means of an electron-