Teltron Tubes

The electron diffraction tube is highly evacuated tube with an electron gun consisting of pure tungsten heater filament and cylindrical anode all contained in clear glass bulb. The electrons emitted by the heated cathode are constrained to narrow beam by an aperture and are then focussed by means of an electron-optical system. The resulting tight, monochromatic beam then passes through micro-mesh nickel grating situated at the aperture of the gun. Onto this grid, thin layer of polycrystalline graphitised carbon has been deposited by vaporisation. This layer affects the electrons in the beam much like diffraction grating. The result of this diffraction is seen in the form of an image comprising two concentric rings that become visible on the fluorescent screen. spot resulting from the un-deflected electron beam continues to be visible at the centre of the rings. Also requires an EHT power supply. Specifications: • Max. filament voltage: 6.3 V AC • Max. anode voltage: 5 kV • Anode current: approx. 0.1 mA at 4 kV

The Fine Beam Tube is used for investigating the deflection of cathode rays in uniform magnetic field produced by pair of 300 mm Helmholtz coils. In addition, it can also be used for quantitative determination of the specific charge of an electron e/m. Located inside glass bulb with neon residual gas atmosphere is an electron gun, which consists of an indirectly heated oxide cathode, Wehnelt cylinder and perforated anode. The gas atoms are ionised along the path of the electrons and narrow, well-defined, luminescent beam is produced. Incorporated measurement marks facilitate parallax-free determination of the diameter of the circular path of the beam deflected in the magnetic field. The Fine Beam Tube is mounted on base with coloured connectors. In order to protect the tube, protective circuit is built into the base, which shuts off any voltage in excess of the base's pre-set cut-off voltage. The protective circuit prevents excessive voltages from damaging the heater filament and ensures ""smooth"" switch-on response once the voltage is applied. Requires 0-300 DC power supply and 300 mm Helmholtz coils. • Filament voltage: to 12 DC • Filament current: 300 to 450 mA • Anode voltage: 200 to 300 V • Anode current: 0.3 mA • Diameter of fine beam path: 20 to 120 mm • Division spacing: 20 mm • Tube diameter: 160 mm • Total height incl. base: 260 mm • Base plate: 115 115 35 mm • Weight: approx. 820 g

The Pair of Helmholtz coils is used for generating homogeneous magnetic field and for the determination of the specific charge of the electron e/m in conjunction with the dual-beam tube. The coils can be switched in parallel or in series. spring clip on the top crossbar is used to mount the Hall sensor during measurements of the magnetic field. The maximum field strength generated by the coils (~ mT) is approximately 750 times weaker than that produced by an MRI machine (~3 T), which are known to be safe for use by people with medical implants such as pacemakers. For use with RA130505. Requires 0-20 DC A power supply. • Coil Dimensions (Dia.): 300 mm • Coil spacing: 150 mm • Number of turns per coil: 124 • DC resistance: 1.2 ohms each • Maximum coil current: 5 A • Maximum coil voltage: 6 V • Maximum flux density at 5 A: 3.7 mT • Weight: 4.1 kg approx.

The dual beam tube can be used to determine the specific charge e/m from the diameter of the path followed by electrons fired into the tube from perpendicularly mounted gun with vertically aligned magnetic field and observation of the spiral path followed by electrons fired axially into coaxial magnetic field. The dual beam tube is partly evacuated electron tube, filled with helium at low pressure and equipped with both axial and perpendicular electron guns. The electron beams are perpendicular to one another and common deflector plate is provided for both guns. The electron beam source is an oxide cathode heated indirectly via heating coil. The electron paths show up as fine, slightly greenish beam due to impact excitation of the helium atoms. Requires 300 or 500 DC power supply. • Filament voltage: max. 7.5 AC/DC • Anode voltage: approx. 150 V DC • Max Anode current <30 mA • Deflector voltage: max. 50 V DC • Glass bulb: 130 mm dia. approx. • Total length: 260 mm approx.

For mounting all demonstration tubes and the optical equivalent. The tube holder consists of powder-coated cast aluminium with clamping fork made of heat resistant plastic and rotatable by 360°. The base plate contains two boreholes for mounting demonstration Helmholtz coils. Including an anti-skid support with three rubber feet. Weight: 1.5 kg. Supplied without tube. Dimensions 230 x 175 x 320 mm (L x W x H).

Pair of Helmholtz coils for generating a uniform magnetic field perpendicular to the axis of the Teltron D series tubes. Teltron Tube Holder D allows the coils to be configured in the Helmholtz geometry or to produce magnetic fields aligned vertically, or coaxial, with respect to the tube axis. The maximum field strength generated by the coils (~ 10 mT) is approximately 300 times weaker than that produced by an MRI machine (~ 3T), which are known to be safe for use by people with medical implants such as pacemakers. Specifications: Number of turns: 320 Max. continuous current: 1.0 A Max. momentary current: 10 min @ 1.5 A; 3 min @ 2 A Effective impedance: 6 Ω Max. field strength: approx. 10 mT Connectors: 4-mm sockets

For demonstrating the straight propagation of electron beams in field-free spaces by projecting the shadow of Maltese cross on fluorescent screen. Also intended for observing the focusing of electron beams by magnetic fields as an introduction to electron optics. The lower section of the maltese cross has hole 3 mm dia. which makes it possible to ascertain the orientation of the cross's shadow under the influence of magnetic fields. Specifications Max. filament voltage: 6.3 V AC Max. anode voltage: 5 kV Anode current: approx. 0.1 mA at 4 kV To perform experiments using the Maltese cross tube, the following equipment is also required: •1 Tube holder (RA67550) and •1 High voltage power supply 5 kV (115 V, 50/60 Hz) or 1 High voltage power supply 5 kV (230 V, 50/60 Hz) •1 Coil from Helmholtz pair of coils (RA67560) •1 DC Power Supply 20 V, 5 A (115 V, 50/60 Hz) or 1 DC Power Supply 20 V, 5 A (230 V, 50/60 Hz) •1 Bar magnet

Highly evacuated electron tube with focusing electron gun and fluorescent screen inclined relative to the beam axis, so that the path of the beam can be seen and the effects of electric and magnetic fields can be studied. The electron beam can be deflected electrically in the electric field of the built-in plate capacitor, and magnetically by using a Helmholtz coil pair D. By adjusting the electric field so that it cancels the magnetic deflection, it is possible to determine the specific charge e/m and the velocity of the electrons. Specifications: Filament voltage: 6.3 V AC Max. anode voltage: 5000 V Anode current: approx. 0.1 mA at 4000 V Max. capacitor voltage: 5000 V Fluorescent screen: approx. 90x60 mm² Glass bulb: approx. 130 mm dia. Total length: approx. 260 mm

For demonstrating the evidence of the particular nature of cathode rays, establishment of negative sign of charge, the ""electron"" as an atomic particle, concept of ""time-base"", operation of cathode ray oscilloscope, simple Lissajous' figures. The diode gun, tungsten wire ""hairpin"" filament and cylindrical collimating anode, projects narrow beam of cathode rays into the evacuated experimental zone. This beam traverses the sphere to impinge on the luminescent screen in spot about 4 mm in diameter. The narrow beam may be deflected in vertical plane to enter the Faraday cage by using Helmholtz Coils. further and horizontal deflection can be obtained using an Auxiliary Coil, thereby constructing simple cathode ray oscilloscope. All connections are made on the Universal Stand. Specifications Max. filament voltage: 6.3 V AC Max. anode voltage: 5 kV Max. capacitor voltage: 500 V Anode current: approx. 0.1 mA at 4 kV (anode)