Lofgren, Edward

Born into a Swedish immigrant family. In 1927, the family moved to Los Angeles , where Edward graduated from school at the height of the Great Depression . Despite the fact that Lofgren was able to enter the California Institute of Technology , due to lack of money, he was not able to start studying there. For two years he attended the Junior College of Los Angeles ( Los Angeles Junior College ), while simultaneously working at various temporary jobs. To complete his studies, in 1936, he transferred to the University of California at Berkeley , where he was noticed by the famous nuclear physicist Ernest Lawrence .

After graduation in 1938–1940, he worked as an assistant to Lawrence, who instructed a young employee to improve the ion source based on uranium hexafluoride , which was used to separate uranium isotopes in the , a type of mass spectrometer . This work led Lofgren to the Manhattan project : he first worked at Oak Ridge at a uranium enrichment plant, and then at Los Alamos worked on detonators in the group of Luis Alvarez . In 1946, he defended his doctoral dissertation at Berkeley based on his research, which had begun before the war.

He spent the next few years at the University of Minnesota , and in 1949, at the invitation of Lawrence, he returned to his laboratory to work on the Bevatron project, a new synchrotron accelerator. Soon after his return, the scientist was able to demonstrate the efficiency of the autophasing principle of Vladimir Wexler and Edwin Macmillan , turning the 37-inch cyclotron into the first synchrocyclotron . Soon Lawrence appointed Lofgren as chief physicist to build a new synchrotron, which he successfully earned in early 1954.

He was considered the leader of one of the research groups at Bevatron, which lost the race for the discovery of the antiproton , but was able to open the antineutron in 1956. In 1960, he initiated the modernization of the accelerator, which was actively used until 1971. Then he became one of the managers of the Bevalac project, during which the synchrotron was connected to the neighboring SuperHILAC linear accelerator , which served as an injector of heavy ions. This combination yielded a number of important results in the physics of relativistic ions and radiation biology and medicine. In 1973, the director of the Lawrence National Laboratory, Andrew Sessler, appointed Lofgren as his deputy for the accelerator unit. In this position, he remained until his resignation in 1979, and in February 1993 he performed his last official act in the laboratory - he took part in the final shutdown ceremony for Bevatron.

Having lived for over a hundred years, he died at his home in Piedmont Gardens ( Piedmont Gardens ) in Oakland (California)

• Richardson JR, Wright BT, Lofgren EJ, Peters B. Development of the Frequency Modulated Cyclotron // Physical Review . - 1948. - Vol. 73. - P. 424-436. - DOI : 10.1103 / PhysRev.73.424 .
• Freier P., Lofgren EJ, Ney EP, Oppenheimer F., Bradt HL, Peters B. Evidence for Heavy Nuclei in the Primary Cosmic Radiation // Physical Review. - 1948. - Vol. 74. - p. 213-217. - DOI : 10.1103 / PhysRev.74.213 .
• Lofgren EJ The Proton Synchrotron // Science . - 1950. - Vol. 111. - P. 295-300. - DOI : 10.1126 / science.111.2882.295 .
• Grunder HA, Hartsough WD, Lofgren EJ Acceleration of Heavy Ions at the Bevatron // Science. - 1971. - Vol. 174. - P. 1128-1129. - DOI : 10.1126 / science.174.4014.1128 .

• Barletta W., Alonso J. Edward Joseph Lofgren // Physics Today . - 2017. - Vol. 70 (2). - P. 69. - DOI : 10.1063 / PT.3.3473 .