Erich Regener and the ionisation maximum of the atmosphere

摘要

In the 1930s the German physicist Erich Regener (1881–1955) did importantwork on the measurement of the rate of production of ionisation deepunder water and in the atmosphere. Along with one of hisstudents, Georg Pfotzer, he discovered the altitude at which the production of ionisationin the atmosphere reaches a maximum, often, but misleadingly, called thePfotzer maximum. Regener was one of the first to estimate the energy densityof cosmic rays, an estimate that was used by Baade and Zwicky to bolstertheir postulate that supernovae might be their source. Yet Regener's name isless recognised by present-day cosmic ray physicists than it should be,largely because in 1937 he was forced to take early retirement by theNational Socialists as his wife had Jewish ancestors. In this paper webriefly review his work on cosmic rays and recommend an alternative naming ofthe ionisation maximum. The influence that Regener had on the field throughhis son, his son-in-law, his grandsons and his students, and through his linkswith Rutherford's group in Cambridge, is discussed in an appendix. Regener wasnominated for the Nobel Prize in Physics by Schr?dinger in 1938. He diedin 1955 at the age of 73.