By pulsating the hydrogen pressure in the Rossi reaction vessel, Rossi is varying the size of the negative hydrogen ions (in terms of atom count of hydrogen atoms confined within the ion) he produces oscillating from small to/from large.
The number of protons produced when the H- ion is compressed by the hydride absorption process is directly proportional to the nuclear energy produced. Reducing the pressure of the hydrogen stops the H- clustering effect and this in tern stops the reaction.
