Albert Ghiorso
 | This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (April 2010) |
Albert Ghiorso | |
|---|---|
 Ghiorso (second from left) at the discovery of Lawrencium (element 103) | |
| Born | July 15, 1915 Vallejo, California, U.S. |
| Nationality | USA |
| Known for | Chemical element discoveries |
| Awards | 2004 Lifetime Achievement Award (Radiochemistry Society), The Potts Medal (Franklin Institute), G. D. Searle and Co. Award (American Chemical Society), Honorary Doctorate (Gustavus Adolphus College), Fellow (American Academy of Arts and Sciences), Fellow (American Physical Society), Guiness Book of World Records (Most Elements Discovered) |
| Scientific career | |
| Fields | Nuclear Scientist |
| Institutions | Lawrence Berkeley National Laboratory |
Albert Ghiorso (born July 15, 1915) is an American nuclear scientist who was a co-discoverer of 12 chemical elements on the periodic table. His research career spanned five decades, from the early 1940s to the late 1990s.
Biography
Early life
Ghiorso was born in Vallejo, California and grew up in Alameda, California. As a teenager, he built radio circuitry and earned a reputation for establishing radio contacts at distances that outdid the military. Albert Einstein was his idol scientist.
He received his BS in electrical engineering from the University of California, Berkeley in 1937. After graduation, he worked for a company that produced emergency communication devices, and invented the world's first commercial Geiger counter. Ghiorso's ability to produce these radiation detectors brought him into contact with the nuclear scientists at the University of California, in particular Glenn Seaborg.
Research
In the early 1940s, Seaborg moved to Chicago to work on the Manhattan Project. He invited Ghiorso to join him, and for the next four years Ghiorso developed sensitive instruments for detecting the radiation associated with nuclear decay, including spontaneous fission. One of Ghiorso's breakthrough instruments was a 48-channel pulse height analyzer, which enabled him to identify the energy, and therefore the source, of the radiation. During this time they discovered two new elements (95, Americium and 96, Curium), although publication was withheld until after the war.
After the war, Seaborg and Ghiorso returned to Berkeley, where they and colleagues used the 60" Crocker cyclotron to produce elements of increasing atomic number by bombarding exotic targets with helium ions. In experiments during 1949-1950, they produced and identified elements 97 (Berkelium) and 98 (Californium). In 1953, in a collaboration with Argonne Lab, Ghiorso and collaborators sought and found elements 99 (Einsteinium) and 100 (Fermium), identified by their characteristic radiation in dust collected by airplanes from the first thermonuclear explosion (the Mike test). In 1955, the group used the cyclotron to produce 17 atoms of element 101 (Mendelevium), the first new element to be discovered atom-by-atom.
In the mid-1950s it became clear that to extend the periodic chart any further, a new accelerator would be needed, and the Berkeley Heavy Ion Accelerator (HILAC) was built, with Ghiorso in charge. That machine was used in the discovery of elements 102-106, each produced and identified, some on the basis of only a few atoms.
With increasing atomic number, the experimental difficulties of producing and identifying a new element increase significantly. In the 1970s and 1980s, resources for new element search at Berkeley were diminishing, and other laboratories (GSI at Darmstadt, Germany and JINR at Dubna, Russia) were able to synthesize elements 107-109. In the early 1990s, the Berkeley and Darmstadt groups made a collaborative attempt to create element 110. Experiments at Berkeley were unsuccessful, but eventually element 110 was found by the GSI group.
In 1999, evidence for two superheavy elements (element 116 and element 118) was published by a group in Berkeley. The discovery group intended to propose the name Ghiorsium for element 118, but eventually the data was found to be faulty, and in 2002 the claims were withdrawn.
In his later years, Ghiorso continued research toward finding superheavy elements, fusion energy, and innovative electron beam sources.
Legacy
Albert Ghiorso is credited with having co-discovered the following elements:
- Americium ca. 1945 (element 95)
- Curium in 1944 (element 96)
- Berkelium in 1949 (element 97)
- Californium in 1950 (element 98)
- Einsteinium in 1952 (element 99)
- Fermium in 1953 (element 100)
- Mendelevium in 1955 (element 101)
- Nobelium in 1958-59 (element 102)
- Lawrencium in 1961 (element 103)
- Rutherfordium in 1969 (element 104)
- Dubnium in 1970 (element 105)
- Seaborgium in 1974 (element 106)
Ghiorso is legendary for his laboratory cleverness. He invented numerous machines and techniques for isolating and identifying heavy elements atom-by-atom. He also conceived the joining of the HILAC and the Bevatron, which he called the Bevalac, enabling new physics research and medical treatment using high energy heavy ions. His concept for a new type of accelerator, the Omnitron, is acknowledged to have been a brilliant advance, but the machine was never built.
Ghiorso is famous among his colleagues for his endless stream of creative "doodles," which define an art form suggestive of fractals.
External references
- Radiochemistry Society awards him the Lifetime Achievement Award
- Image from LBL archives. Ghiorso is center of the three.
