Geiger, Hans Wilhelm (30 September 1882 – 24 September 1945): German physicist

He was German physicist, who invented the Geiger counter. Geiger was born on 30 September, 1882, in Neustadt in der Rhein-Pfalz, one of Germany’s loveliest wine districts.

The son of philologist, Geiger was educated in the Universities of Munich and Erlangen where he obtained his PhD in 1906. At the University of Erlangen, he worked with Eilhard Wiedemann (1852-1928) and wrote a thesis on electrical discharges through gases.

His first academic appointment took him to Manchester University as assistant to Professor Arthur Schuster (1851 – 1934).

In the following year Schuster was succeeded by Ernest Rutherford. In 1908, in cooperation with Rutherford, Geiger investigated the nature of the alpha particle, showing that it had a double positive charge.

In 1911 Geiger and John Mitchell Nuttall discovered the Geiger–Nuttall law (or rule) and performed experiments that led to Rutherford's atomic model.

Geiger also designed instrument capable of detecting and counting alpha particles. These were the prototype of the counter Geiger developed in the 1920s with W. Muller, which has since become widely known as the Geiger counter (or Geiger Muller counter). Geiger returned to Germany in 1912 to direct the Physikalisch Technische Reichanstalt in Berlin.

He later held chairs of physics at the Universities of Kiel (1925-29) and Tubingen (1929-36). In 1936, he was appointed head of physics at the technical University, Charlottenburg.

His great achievements are the Geiger-Nuttall relation, Geiger point counter Geiger-Muller counter and the coincidence principle.

The introduction in July 1928 of the Geiger-Müller counter marked the introduction of modern electrical devices into radiation research.
Geiger, Hans Wilhelm (30 September 1882 – 24 September 1945): German physicist