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This paper summarizes experiments that use a vacuum tube to determine the magnetic field necessary to prevent electrons from reaching the anode in a high vacuum diode. In addition to determining this magnetic cutoff for a given electron energy, the experiment includes the determination of the magnetic flux of an air-core solenoid and the calculation of the velocity of 10-volt electrons. This summary also lays the foundation for determining the electron charge-to-mass ratio (e/m) using data collected in this experiment. This experiment is based on the Hull method devised by the inventor of the magnetron diode tube in 1921.

An electromagnet?s flux increases linearly with current, but levels off as the magnet becomes saturated.

This article describes some experiments that demonstrated direct energy conversion from an NRC-exempt americium-241 alpha-particle source that produced a measurable potential of about 0.3 volts. The principle is sound, but a large and perhaps impractical quantity of americium-241 would be required for observing any significant electrical output above the noise level. These experiments were very instructive regarding the ionization process, direct energy conversion and low-level current measurements.

This paper describes the theory, construction and initial tests for an enclosed spark gap, otherwise known as a spark gap tube. This spark gap tube was used in place of a conventional open-air spark gap in the primary circuit of a small bipolar Tesla coil. The experimental results indicate that this spark gap tube is quiet and rapidly deionizing (quenching), and does not reduce the Tesla coil output. The spark gap tube used in this experiment is similar to ones used in early high-voltage switching research, conducted during World War II toward the development of radar.

Raney constructed and tested a small bipolar Tesla coil modeled after designs used in physics laboratories in the past. His inspiration for this design came from ?Tesla Coils Resurrected,? TCBA News, vol. 17, no. 2 (April-June), 1998. The featured Tesla coil came from a 1936 Chicago Apparatus Company advertisement. This Tesla coil is a variation of the other more common form of Tesla coil wherein the secondary coil is vertical with one discharge terminal. (The other terminal is grounded.)

This paper summarizes experiments that use magnetic fields to control the current in discharge tubes. In theory, the trajectory of electrons, in a magnetic field applied parallel to their initial direction of motion, describes a spiral path as these electrons follow the magnetic field lines. This results in an overall longer path with a higher probability of ionizing more gas molecules with a resulting increase in current (Yarwood 1945). In these experiments, the magnetic field was oriented parallel to the stream of electrons emitted from a cold cathode in a discharge tube. The experiments determined the magnetic field strength necessary to control tube current by lengthening the electron path.