Heating of the ambient ionosphere by an artificially injected electron beam

An electrostatic analyzer on the electron accelerator of the Electron Echo 2 experiment showed that the electrons of the background plasma were heated to 10,000°K or more within 8 ms of the start of gun pulses. The degree of heating was dependent on the orientation of the rocket with respect to the magnetic field but was not measurably dependent on ambient electron density or neutral atmosphere density or on the pitch angle at which the 40‐keV electron beam was injected. This heating was also accompanied by an increase of plasma density. No evidence was found for an ion‐free region around the rocket during gun pulses. These observations show that significant amounts of ionization are taking place around the rocket. During part of the flight a two‐temperature electron distribution was found. It is believed that the high‐temperature part of these distributions represents secondaries produced by the beam.