Gerhard Dickel (28 October 1913 – 3 November 2017) was a German

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

and

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

. He developed a thermal diffusion method of separating isotopes with

Klaus Clusius Klaus Paul Alfred Clusius (19 March 1903 – 28 May 1963) was a German physical chemist. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club; he worked on isotope separation techniques and heavy wa ...

in 1938, sometimes referred to as Clusius-Dickel separation. Clusius-Dickel_separation_DMarshall2021

Biography

He was born in

Augsburg Augsburg ( , ; ; ) is a city in the Bavaria, Bavarian part of Swabia, Germany, around west of the Bavarian capital Munich. It is a College town, university town and the regional seat of the Swabia (administrative region), Swabia with a well ...

. He studied under Clusius at the Institute for Physical Chemistry of the

Ludwig Maximilian University of Munich The Ludwig Maximilian University of Munich (simply University of Munich, LMU or LMU Munich; ) is a public university, public research university in Munich, Bavaria, Germany. Originally established as the University of Ingolstadt in 1472 by Duke ...

. Clusius and Dickel published a paper in 1938 announcing that they had separated isotopes of

neon Neon is a chemical element; it has symbol Ne and atomic number 10. It is the second noble gas in the periodic table. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with approximately two-thirds the density of ...

. They had discovered that the normally inefficient thermal diffusion method – where isotopes in a fluid diffuse towards opposing hotter and colder regions – could be improved by more than four orders of magnitude if there was also an optimal convection current between the regions to avoid a steady concentration gradient and "back diffusion" developing. In 1939, the year Dickel defended his PhD thesis, the pair announced that they had also separated isotopes of chlorine with the same process. It was explored on a large scale in the USA during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

as a possible method for separating

uranium-235 Uranium-235 ( or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nat ...

from the more abundant

uranium-238 Uranium-238 ( or U-238) is the most common isotope of uranium found in nature, with a relative abundance of 99%. Unlike uranium-235, it is non-fissile, which means it cannot sustain a chain reaction in a thermal-neutron reactor. However, it i ...

in order to make an

atomic bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

(the more-efficient

gaseous diffusion Gaseous diffusion is a technology that was used to produce enriched uranium by forcing gaseous uranium hexafluoride (UF6) through microporous membranes. This produces a slight separation (enrichment factor 1.0043) between the molecules containi ...

was eventually chosen). Dickel became a substitute manager of the Institute for

Physical Chemistry Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mech ...

, followed by a position as adjunct professor. In 1957, he became head of department at the university's Physics Institute. The same year he received the Bodenstein Prize from the German Bunsen Society for Physical Chemistry, for work on isotope exchange and on diffusion in gases and gels. He retired in 1978. He died in 2017, aged 104.

References

1913 births 2017 deaths Ludwig Maximilian University of Munich alumni 20th-century German chemists 21st-century German chemists 20th-century German physicists Scientists from Augsburg German men centenarians {{Germany-chemist-stub