ألبرت گيورسو

(تم التحويل من ألبرت گيورسو)
ألبرت گيورسو
Albert Ghiorso
Albert Ghiorso ca 1970.jpg
ألبرت گيورسو، حوالي 1970
وُلِدَ15 يوليو 1915
ڤاليهو، كاليفورنيا، الولايات المتحدة
توفيديسمبر 26, 2010(2010-12-26) (aged 95)
بركلي، كاليفورنيا، الولايات المتحدة
اللقباكتشاف عناصر كيميائية
الجوائز2004 جائزة الإنجاز مدى الحياة (جمعية الكيمياء الإشعاعية)،[1] وسام پوتس (معهد فرانكلن)، جائزة ج.د. سيرل (الجمعية الكيميائية الأمريكية)، دكتوراه فخرية (كلية گوستاڤوس أدولفوس)، زميل (الأكاديمية الأمريكية للفنون والعلوم)، زميل (الجمعية الفيزيائية الأمريكية)، موسوعة جينيس للأرقام القياسية (أكبر عدد من العناصر المُكتشَفة)
السيرة العلمية
المجالاتالعلم النووي
الهيئاتمختبر لورنس بركلي الوطني

ألبرت گيورسو ( Albert Ghiorso ؛ 15 يوليو 1915 – 26 ديسمبر 2010) كان عالم نووي أمريكي وشارك في اكتشاف عدد قياسي من العناصر الكيميائية في الجدول الدوري. سيرته البحثية امتدت لست عقود، من مطلع ع1940 حتى أواخر ع1990.

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السيرة

الحياة المبكرة

Ghiorso was born في Vallejo, California on July 15, 1915, of Italian and Spanish ancestry.[2] He grew up في Alameda, California.[3] Living near the Oakland International Airport, he became interested في airplanes, aeronautics, and other technologies.[4] After graduating from high school, he built radio circuitry and earned a reputation for establishing radio contacts at distances that outdid the military.[5]

He received his BS في electrical engineering from the University of California, Berkeley في 1937.[4] After graduation, he worked for Reginald Tibbets, a prominent amateur radio operator who operated a business supplying radiation detectors to the government. Ghiorso's ability to develop and produce these instruments, as well as a variety of electronic tasks, brought him into contact with the nuclear scientists at the University of California Radiation Laboratory at Berkeley, في particular Glenn Seaborg. During a job في which he was to install an intercom at the lab, he met two secretaries, one of whom married Seaborg. The other, Wilma Belt, became Albert's wife of 60+ years.[6]

Ghiorso was raised في a devout Christian family, but later left the religion and became an atheist. However, he still identified with Christian ethics.[7][8]

الأبحاث في زمن الحرب

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.[9]

العناصر الجديدة

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. في experiments during 1949–1950, they produced and identified elements 97 (berkelium) and 98 (californium). في 1953, في a collaboration with Argonne Lab, Ghiorso and collaborators sought and found elements 99 (einsteinium) and 100 (fermium), identified by their characteristic radiation في dust collected by airplanes from the first thermonuclear explosion (the Mike test). في 1955, the group used the cyclotron to produce 17 atoms of element 101 (mendelevium), the first new element to be discovered atom-by-atom. The recoil technique invented by Ghiorso was crucial to obtaining an identifiable signal from individual atoms of the new element.

Ghiorso updates a periodic table في 1961 with the newly discovered element lawrencium while co-discoverers Robert Latimer, Torbjorn Sikkeland and Almon Larsh look on.

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 Linear Accelerator (HILAC) was built, with Ghiorso في charge. That machine was used في the discovery of elements 102–106 (102, nobelium; 103, lawrencium; 104, rutherfordium; 105, dubnium and 106, seaborgium), each produced and identified on the basis of only a few atoms. The discovery of each successive element was made possible by the development of innovative techniques في robotic target handling, fast chemistry, efficient radiation detectors, and computer data processing. The 1972 upgrade of the HILAC to the superHILAC provided higher intensity ion beams, which was crucial to producing enough new atoms to enable detection of element 106.

With increasing atomic number, the experimental difficulties of producing and identifying a new element increase significantly. في the 1970s and 1980s, resources for new element research at Berkeley were diminishing, but the GSI laboratory at Darmstadt, Germany, under the leadership of Peter Armbruster and with considerable resources, was able to produce and identify elements 107–109 (107, bohrium; 108, hassium and 109, meitnerium). في the early 1990s, the Berkeley and Darmstadt groups made a collaborative attempt to create element 110. Experiments at Berkeley were unsuccessful, but eventually elements 110–112 (110, darmstadtium; 111, roentgenium and 112, copernicium) were identified at the Darmstadt laboratory. Subsequent work at the JINR laboratory at Dubna, led by Yuri Oganessian and a Russian-American team of scientists, was successful في identifying elements 113–118 (113, nihonium; 114, flerovium; 115, moscovium; 116, livermorium; 117, tennessine and 118, oganesson), thereby completing the Period 7 elements of the periodic table of the elements.

الاختراعات

Ghiorso invented numerous techniques and machines for isolating and identifying heavy elements atom-by-atom. He is generally credited with implementing the multichannel analyzer and the technique of recoil to isolate reaction products, although both of these were significant extensions of previously understood concepts. His concept for a new type of accelerator, the Omnitron, is acknowledged to have been a brilliant advance that probably would have enabled the Berkeley lab to discover numerous additional new elements, but the machine was never built, a victim of the evolving political landscape of the 1970s في the U.S. that de-emphasized basic nuclear research and greatly expanded research on environmental, health, and safety issues. Partially as a result of the failure to build the Omnitron, Ghiorso (together with colleagues Bob Main and others) conceived the joining of the HILAC and the Bevatron, which he called the Bevalac. This combination machine, an ungainly articulation across the steep slope at the Rad Lab, provided heavy ions at GeV energies, thereby enabling development of two new fields of research: "high-energy nuclear physics," meaning that the compound nucleus is sufficiently hot to exhibit collective dynamical effects, and heavy ion therapy, في which high-energy ions are used to irradiate tumors في cancer patients. Both of these fields have expanded into activities في many laboratories and clinics worldwide.[10]

الحياة اللاحقة

In his later years, Ghiorso continued research toward finding superheavy elements, fusion energy, and innovative electron beam sources. He was a non-participating co-author of the experiments في 1999 that gave evidence of elements 116 and 118, which later turned out to be a case of scientific fraud perpetrated by the first author, Victor Ninov. He also had brief research interests في the free quark experiment of William Fairbank of Stanford, في the discovery of element 43, and في the electron disk accelerator, among others.

الذكرى

Albert Ghiorso is credited with having co-discovered the following elements[11]

Ghiorso personally selected some of the names recommended by his group for the new elements. His original name for element 105 (hahnium) was changed by the International Union of Pure and Applied Chemistry (IUPAC) to dubnium, to recognize the contributions of the laboratory at Dubna, Russia, في the search for trans-fermium elements. His recommendation for element 106, seaborgium, was accepted only after extensive debate about naming an element after a living person. في 1999, evidence for two superheavy elements (element 116 and element 118) was published by a group في Berkeley. The discovery group intended to propose the name ghiorsium for element 118, but eventually the data were found to have been tampered and في 2002 the claims were withdrawn. Ghiorso's lifetime output comprised about 170 technical papers, most published في The Physical Review.

Ghiorso was famous among his colleagues for his endless stream of creative "doodles," which define an art form suggestive of fractals. He also developed a state-of-the-art camera for birdwatching, and was a constant supporter of environmental causes and organizations.

Several obituaries are available online, and a full-length biography is في preparation.[12]

الهامش

  1. ^ Radiochemistry Society Lifetime Achievement Award
  2. ^ Schmieder, Robert W. "Albert Ghiorso Obituary".
  3. ^ paulpreuss (2011-01-03). "In Memorian, Albert Ghiorso, 1915-2010 - Berkeley Lab". Berkeley Lab News Center (in الإنجليزية الأمريكية). Retrieved 2023-12-25.
  4. ^ أ ب Schmeider, Robert W. (July 2011). "Albert Ghiorso" (PDF). Physics Today. 64 (7): 63–64. Bibcode:2011PhT....64g..63S. doi:10.1063/PT.3.1176. Retrieved July 21, 2023.
  5. ^ Hoffman, Darleane C.; Ghiorso, Albert; Seaborg, Glenn T. (2000). The Transuranium People: The Inside Story. World Scientific. Bibcode:2000tpis.book.....H. doi:10.1142/p074. ISBN 978-1-86094-087-3.
  6. ^ Weil, Martin (2011-01-20). "Scientist pushed periodic table, discovered 12 elements". Washington Post. p. B5.
  7. ^ Schmieder, Robert W., Albert Ghiorso – Notes for Memoirs, January 2010
  8. ^ Seaborg, Glenn Theodore, et al., Transuranium People: The Inside Story, Imperial College Press, 2000
  9. ^ "Today at Berkeley Lab: Al Ghiorso's Long and Happy Life". Archived from the original on 2020-02-12. Retrieved 2010-12-28.
  10. ^ Albert Ghiorso, Robert M. Main, and Bob H. Smith, "The Omnitron: A Versatile Medium-Energy Synchrotron for the Acceleration of Light and Heavy Ions", Proceedings of the International Conference on Isochronous Cyclotrons, Gatlinburg, Tennessee, 1966, IEEE Transactions on Nuclear Science, NS-13, no. 4, August 1966, p. 280–287
  11. ^ "Annotated Bibliography for Albert Ghiorso, The Alsos Digital Library for Nuclear Issues". Archived from the original on 2010-08-04. Retrieved 2019-09-21.
  12. ^ "ALBERT GHIORSO".

المراجع

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