3B Scientific™ Fine Beam Tube

Description

For examining the deflection of electron beams in a uniform magnetic field using a pair of Helmholtz coils and for the quantitative determination of the specific charge of the electron.

The gas atoms are ionized along the electron path and produce a sharply defined, visible fluorescent beam. The tube is mounted on a base with color coded connectors.

Experiment topics:

• Deflection of electrons in a closed circular path inside a magnetic field
• Determination of specific charge of an electron e/m

The evacuated glass tube is integrated with an electron beam system consisting of:

• an indirectly heated oxide cathode
• a Wehnelt cylinder and a perforated anode
• residual gas atmosphere with set gas pressure
• integrated measurement marks for parallax-free measurements
• Gas filling: Neon
• Gas pressure: 1.3 x 10-5 hPa
• Filament voltage: 4 to 10V AC/DC
• Filament current: 300 to 450mA
• Wehnelt voltage: 0 to -50V
• Anode voltage: 200 to 300V
• Anode current: <0.3mA
• Circular path diameter: 20 to 120mm
• Division spacing: approx. 20mm
• Tube diameter: approx. 160mm

Specifications

• Product Type: Fine Beam Tube
• Height (English): 10.2 in.
• Height (Metric): 26 cm
• Voltage: 4 to 10 VAC/VDC (filament), 0 to 50 V (fehnelt), 200 to 300 V (anode)
• Weight (English): 1.5 lb.
• Weight (Metric): 0.7 kg
• Amperage: <0.3mA, <150mA
• Gas Pressure: 1.3 x 10-5 hPa
• Diameter (Metric) Tube: 16 cm
• Diameter (English) Tube: 6.2 in.
• Includes: Indirectly heated Oxide cathode, wehnelt cylinder and a perforated anode, residual Gas atmosphere with set Gas pressure, integrated measurement marks for parallax-free measurements, 16cm dia. tube mounted on a base with color coded connectors