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Arne Claes Olof Johnson (born 21th of June 1944) is a Swedish nuclear physicist. He is most known for the discovery of the 'backbend'[1][2] and became instrumental for the development of large detector arrays like Nordball[3] and EUROBALL[4]. He is Emeritus[clarification needed] in Nuclear physics at the KTH Royal Institute of Technology.

Bibliography

Arne Johnson studied Engineering physics at KTH Royal Institute of Technology in 1963 -1967. After completion, he started his PhD in Nuclear spectroscopy under supervision of Sven Hjorth and Hans Ryde. He discovered irregularities in the spectrum of 160Dy(Dysprosium)[5] during his PhD research. The electronic engineer Jozef Sztarkier developed an electronic circuit such that the following experiment could indeed prove that the irregularity belonged to the same structure in 160Dy[1]. Further experiments revealed even stronger irregularities in the spectrum of the nucleus of 162Er(Erbium) where the figure of the Moment of inertia shows a 'backbend'[2]. The irregularity was interpreted at that time as a Phase transition[5] which also became the title of Arne Johnson thesis 1973, 'Evidence for phase transitions in deformed nuclei'. Together with the theoretical nuclear physicist Zdzisław Szymański the emerging field of nuclear rotational states (see also Rotational spectroscopy) was described in a review paper[6]. Arne Johnson received the academic title of a Docent in 1974 (see Academic ranks in Sweden). Following international visits at a large number of leading laboratories in both Europe and the US, like the Niels Bohr Institute, Denmark, Daresbury Laboratory, he was appointed adjoint professor at KTH Royal Institute of Technology in 1986 and full professor in Nuclear physics 1997. He was honored with the Borelius medal for his achievements in physics and as Dean of the engineering science faculty at KTH (see [1]).

During his military service at the FOA (Swedish National Defence Research Institute) 1977-1978, he was responsible in developing a Gamma-ray spectrometer for radioactive Xenon leaking from underground bomb test. Lateron, he initiated with Nordic nuclear physicist the development of the advanced detector system Nordball[3] and became the Swedish representative for the European detector system EUROBALL[4].

References

  1. ^ a b Johnson, A.; Ryde, H.; Sztarkier, J. (1971). "Evidence for a "singularity" in the nuclear rotational band structure". Physics Letters B. 34 (7): 605–608. Bibcode:1971PhLB...34..605J. doi:10.1016/0370-2693(71)90150-X – via elsevier science direct.
  2. ^ a b Johnson, A.; Ryde, H.; Hjorth, S.A. (1972). "Nuclear moment of inertia at high rotational frequencies". Nuclear Physics A. 179 (3): 753–768. Bibcode:1972NuPhA.179..753J. doi:10.1016/0375-9474(72)90617-3.
  3. ^ a b Herskind, Bent (1986). "The NORDBALL — A multidetector system for the study of nuclear structure". Nuclear Physics A. 447: 395–412. Bibcode:1986NuPhA.447..395H. doi:10.1016/0375-9474(86)90619-6.
  4. ^ a b Simpson, J. (1997). "The Euroball Spectrometer". Zeitschrift für Physik a Hadrons and nuclei. 358 (2): 139–143. Bibcode:1997ZPhyA.358..139S. doi:10.1007/s002180050290. ISSN 0939-7922. S2CID 124091023.
  5. ^ a b Wyss, R.; Riley, M. A. (2022-04-03). "Fifty Years of Backbending". Nuclear Physics News. 32 (2): 16–20. Bibcode:2022NPNew..32b..16W. doi:10.1080/10619127.2022.2063000. ISSN 1061-9127. S2CID 249680104.
  6. ^ Johnson, A.; Szymański, Z. (1973). "Nuclear rotation at high angular velocities". Physics Reports. 7 (4): 182–222. Bibcode:1973PhR.....7..182J. doi:10.1016/0370-1573(73)90012-4.