Kevin Insik Hahn

Last updated
Kevin Insik Hahn
Kevin Insik Hahn nuclear physicist haninsig.jpg
Born(1962-01-11)January 11, 1962
Gangwon Province, South Korea
Alma mater UCLA, Yale University
Scientific career
Fields Nuclear astrophysics, nuclear physics, rare decay experiments, science education
Institutions Caltech, RIKEN, Ewha Womans University, University of Houston, Brookhaven National Laboratory, RISP, Institute for Basic Science
Thesis The 17F(p,γ)18Ne and 14O(α,p)17F Reaction Rates and the Structure of 18Ne  (1993)
Doctoral advisor Peter Parker
Korean name
Hangul
한인식
Hanja
Revised Romanization Han Insik
McCune–Reischauer Han Insik
Website Center for Exotic Nuclear Studies

Kevin Insik Hahn is a South Korean physicist who is an expert in the fields of nuclear physics and nuclear astrophysics. [1] [2] Since December 2019, he has been the director of the Center for Exotic Nuclear Studies at the Institute for Basic Science (IBS) in South Korea. He also holds an endowed professorship in the Department of Science Education at Ewha Womans University, where he has worked since 1999. In his research, he has worked on accelerator-based as well as non-accelerator-based experiments. His current research activities involve a number of accelerators around the world, including the RI Beam Factory (RIBF) at RIKEN, Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, and the soon-to-open Rare isotope Accelerator complex for ON-line experiment (RAON). During his tenure at Ewha Womans University, he promoted STEM/STEAM education by serving for multiple years as the director of the Advanced STEAM Teacher Education Center. He also wrote several physics textbooks for high school students and undergraduate students.

Contents

Education

Hahn obtained a B.S. in physics from University of California, Los Angeles (UCLA) in 1984. He then enrolled in Yale University and graduated with a M.S. in physics in 1989 and a Ph.D. in nuclear astrophysics in 1993. His doctoral thesis was on the reaction rates of 17F(p,γ)18Ne and 14O(α,p)17F and was supervised by Peter Parker.

Career

Hahn went to Caltech and worked for three years as a research fellow in the Kellogg Radiation Laboratory with Ralph Kavanagh. Relocating to Japan, he spent the next two years as a research fellow at RIKEN becoming an official RIKEN Fellow from 1996 to 1997. As a Fellow, he worked with Ishihara at the Radiation Laboratory at RIKEN and also worked closely with Motobayashi and Kubono. The next year he worked as a research professor in the University of Houston teaching an undergraduate course on electromagnetism and conducted hypernuclear experiments at Brookhaven National Laboratory and rare decay experiments. From 1999, he worked as a professor in the Department of Science Education, Ewha Womans University, Korea including as an invited chair professor. [3] [4] [5] From 2014, he has worked as a visiting scholar with RAON and the IBS Center for Underground Physics where he worked with KIMS (dark matter search), AMoRE (double beta decay experiment), and the HPGe Array. [6] [7]

Working mainly on silicon detector for the PHENIX collaboration, [8] he and collaborators found evidence of the quark–gluon plasma, which can be made in small-scale collision systems. Working with colleagues, he participated in experiments confirming atomic nuclei with 34 neutrons are more stable than expected. [9] Earlier experiments theorized this but had been unable to confirm it. [10]

In late 2019, Hahn became the founding director of the IBS Center for Exotic Nuclear Studies. Divided into four groups; experimental nuclear astrophysics, experimental nuclear structure, experimental nuclear reaction and theoretical nuclear physics, research of the center uses rare isotope beams from overseas RI accelerators and later the Rare Isotope Science Project's (RISP) RAON accelerator in Korea, specifically RISP's KOrea Broad acceptance Recoil spectrometer and Apparatus (KOBRA) with a focus on discovering rare isotopes and investigating the origins of heavy elements. His work will help direct collaborations among universities and research groups studying rare isotope accelerator sciences in South Korea. [11]

Awards and honors

Committee work

Selected publications

Related Research Articles

<span class="mw-page-title-main">Neutron</span> Subatomic particle with no charge

The neutron is a subatomic particle, symbol
n
 or
n0
, which has a neutral charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, they are both referred to as nucleons. Nucleons have a mass of approximately one atomic mass unit, or dalton, symbol Da. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks.

<span class="mw-page-title-main">Island of stability</span> Predicted set of isotopes of relatively more stable superheavy elements

In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. Its theoretical existence is attributed to stabilizing effects of predicted "magic numbers" of protons and neutrons in the superheavy mass region.

<span class="mw-page-title-main">Nihonium</span> Chemical element, symbol Nh and atomic number 113

Nihonium is a synthetic chemical element; it has symbol Nh and atomic number 113. It is extremely radioactive: its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13.

A tetraneutron is a hypothetical stable cluster of four neutrons. The existence of this cluster of particles is not supported by current models of nuclear forces. There is some empirical evidence suggesting that this particle does exist, based on a 2001 experiment by Francisco-Miguel Marqués and co-workers at the Ganil accelerator in Caen using a novel detection method in observations of the disintegration of beryllium and lithium nuclei. However, subsequent attempts to replicate this observation have failed.

<span class="mw-page-title-main">ISOLDE</span> Physics facility at CERN

The ISOLDE Radioactive Ion Beam Facility, is an on-line isotope separator facility located at the centre of the CERN accelerator complex on the Franco-Swiss border. Created in 1964, the ISOLDE facility started delivering radioactive ion beams (RIBs) to users in 1967. Originally located at the Synchro-Cyclotron (SC) accelerator, the facility has been upgraded several times most notably in 1992 when the whole facility was moved to be connected to CERN's ProtonSynchroton Booster (PSB). ISOLDE is currently the longest-running facility in operation at CERN, with continuous developments of the facility and its experiments keeping ISOLDE at the forefront of science with RIBs. ISOLDE benefits a wide range of physics communities with applications covering nuclear, atomic, molecular and solid-state physics, but also biophysics and astrophysics, as well as high-precision experiments looking for physics beyond the Standard Model. The facility is operated by the ISOLDE Collaboration, comprising CERN and sixteen (mostly) European countries. As of 2019, close to 1,000 experimentalists around the world are coming to ISOLDE to perform typically 50 different experiments per year.

Naturally occurring manganese (25Mn) is composed of one stable isotope, 55Mn. 26 radioisotopes have been characterized, with the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the remaining radioactive isotopes have half-lives that are less than 3 hours and the majority of these have half-lives that are less than a minute. This element also has 3 meta states.

Naturally occurring vanadium (23V) is composed of one stable isotope 51V and one radioactive isotope 50V with a half-life of 2.71×1017 years. 24 artificial radioisotopes have been characterized (in the range of mass number between 40 and 65) with the most stable being 49V with a half-life of 330 days, and 48V with a half-life of 15.9735 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, the majority of them below 10 seconds, the least stable being 42V with a half-life shorter than 55 nanoseconds, with all of the isotopes lighter than it, and none of the heavier, have unknown half-lives. In 4 isotopes, metastable excited states were found (including 2 metastable states for 60V), which adds up to 5 meta states.

Calcium (20Ca) has 26 known isotopes, ranging from 35Ca to 60Ca. There are five stable isotopes, plus one isotope (48Ca) with such a long half-life that for all practical purposes it can be considered stable. The most abundant isotope, 40Ca, as well as the rare 46Ca, are theoretically unstable on energetic grounds, but their decay has not been observed. Calcium also has a cosmogenic isotope, radioactive 41Ca, which has a half-life of 99,400 years. Unlike cosmogenic isotopes that are produced in the atmosphere, 41Ca is produced by neutron activation of 40Ca. Most of its production is in the upper metre of the soil column, where the cosmogenic neutron flux is still sufficiently strong. 41Ca has received much attention in stellar studies because it decays to 41K, a critical indicator of solar system anomalies. The most stable artificial radioisotopes are 45Ca with a half-life of 163 days and 47Ca with a half-life of 4.5 days. All other calcium isotopes have half-lives measured in minutes or less.

Although there are nine known isotopes of helium (2He), only helium-3 and helium-4 are stable. All radioisotopes are short-lived, the longest-lived being 6
He
 with a half-life of 806.92(24) milliseconds. The least stable is 10
He
, with a half-life of 260(40) yoctoseconds, although it is possible that 2
He
 may have an even shorter half-life.

Hassium (108Hs) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 265Hs in 1984. There are 13 known isotopes from 263Hs to 277Hs and 1–4 isomers. The most stable isotope of hassium cannot be determined based on existing data due to uncertainty that arises from the low number of measurements. The half-lives of 269Hs and 271Hs are about 12 seconds, whereas that of 270Hs is about 7.6 seconds. It is also possible that 277mHs is more stable than these, with its half-life likely being 130±100 seconds, but only one event of decay of this isotope has been registered as of 2016.

Roentgenium (111Rg) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 272Rg in 1994, which is also the only directly synthesized isotope; all others are decay products of heavier elements. There are seven known radioisotopes, having mass numbers of 272, 274, and 278–282. The longest-lived isotope is 282Rg with a half-life of about 2 minutes, although the unconfirmed 283Rg and 286Rg may have longer half-lives of about 5.1 minutes and 10.7 minutes respectively.

Flerovium (114Fl) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 289Fl in 1999. Flerovium has six known isotopes, along with the unconfirmed 290Fl, and possibly two nuclear isomers. The longest-lived isotope is 289Fl with a half-life of 1.9 seconds, but 290Fl may have a longer half-life of 19 seconds.

Livermorium (116Lv) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 293Lv in 2000. There are five known radioisotopes, with mass numbers 288 and 290–293, as well as a few suggestive indications of a possible heavier isotope 294Lv. The longest-lived known isotope is 293Lv with a half-life of 70 ms.

Oganesson (118Og) is a synthetic element created in particle accelerators, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first and only isotope to be synthesized was 294Og in 2002 and 2005; it has a half-life of 700 microseconds.

Ununennium (119Uue) has not yet been synthesised, so all data would be theoretical and a standard atomic weight cannot be given. Like all synthetic elements, it would have no stable isotopes.

<span class="mw-page-title-main">Hendrik Schatz</span> German physicist

Hendrik Schatz is a professor of Nuclear Astrophysics at Michigan State University. He earned his Diploma from the University of Karlsruhe in 1993, and his PhD from the University of Heidelberg in 1997 after completing his thesis work at the University of Notre Dame. He is one of the Principal Investigators for the Joint Institute for Nuclear Astrophysics and is a leading expert on nuclear astrophysics,. Schatz also serves the science advisory committees for the Facility for Rare Isotope Beams and GSI. Hendrik's primary field of expertise is Type I X-ray Bursts. His most notable contribution to this field is the discovery of the SnTeSb-cycle. Hendrik was featured in Science magazine November 22, 2002 for his work on experimental nuclear astrophysics. Hendrik has also contributed to Physics Today.

<span class="mw-page-title-main">Mujaddid Ahmed Ijaz</span> Pakistani-American experimental physicist

Mujaddid Ahmed Ijaz, Ph.D., was a Pakistani-American experimental physicist noted for his role in discovering new isotopes that expanded the neutron-deficient side of the atomic chart. Some of the isotopes he discovered enabled significant advances in medical research, particularly in the treatment of cancer, and further advanced the experimental understanding of nuclear structures. Ijaz conducted his research work at Oak Ridge National Laboratories (ORNL). He and his ORNL colleagues published more than 60 papers in physics journals announcing isotope discoveries and other results of their accelerator experiments from 1968 until 1983.

<span class="mw-page-title-main">Institute for Basic Science</span> Science institute in South Korea

The Institute for Basic Science is a Korean government-funded research institute that conducts basic science research and relevant pure basic research. Comprising approximately 30 research centers with more than 60 research groups across the nation and a headquarters in Daejeon, IBS has approximately 1,800 researchers and doctoral course students. Around 30% of the researchers are from countries outside South Korea. The organization is under the Ministry of Science and ICT.

<span class="mw-page-title-main">RAON</span>

RAON is a South Korean particle physics laboratory within the Rare Isotope Science Project (RISP) that is being constructed in the outskirts of Daejeon neighboring Sejong, South Korea by the Institute for Basic Science (IBS). It was expected to be finished by 2021 before getting pushed back to 2025.

Alexandre Obertelli is a French experimental nuclear physicist and Alexander von Humboldt Professor of Experimental Nuclear Structure Physics at the Institute of Nuclear Physics of the Technische Universität Darmstadt.

References

  1. ↑ 이시하라, 마사야수 (December 2016). "원자핵물리학분야에서 이루어진 한일 연구협력의 역사(2)*" (PDF) (in Korean). Korean Physical Society . Retrieved 11 February 2020. 오늘날 한국에서는 대형RI 빔 연구시설 RISP의 건설이 추진되고 있으나, RI 빔 물리분야가 세계적으로 대두하기 시작한 1990년대 초 재빨리이 분야 연구를 시도한 문창범, 김용균, 한인식 박사는 지금 한국의 원자핵물리 학 연구를 이끌어 가는 위치에 있습니다.
  2. ↑ "IBS launching two HQ Research Centers". Institute for Basic Science . 16 December 2019. Retrieved 11 February 2020. Director Hahn is recognized by his outstanding achievements in nuclear astrophysics.
  3. ↑ "College of Education Faculty". Ewha Womans University . Retrieved 23 March 2020.
  4. ↑ "교수프로필: Kevin Insik Hahn Invited chair-professor". Ewha Womans University . Retrieved 27 March 2020.
  5. ↑ "과학교육과". Ewha Womans University . Retrieved 27 March 2020. 한인식() 초빙석좌교수
  6. ↑ "Insik Hahn". IBS Center for Underground Physics. Institute for Basic Science. 23 March 2019. Retrieved 11 February 2020.
  7. ↑ "Collaboration". IBS Center for Underground Physics. Institute for Basic Science . Retrieved 11 February 2020.
  8. ↑ PHENIX Collaboration (10 December 2018). "Creation of quark–gluon plasma droplets with three distinct geometries". Nature Physics. 15 (3): 214–220. arXiv: 1805.02973 . doi:10.1038/s41567-018-0360-0. S2CID   195367932 . Retrieved 27 March 2020.
  9. ↑ S. Chen; J. Lee; P. Doornenbal; A. Obertelli; C. Barbieri; et al. (30 September 2019). "Quasifree Neutron Knockout from 54Ca Corroborates Arising N=34 Neutron Magic Number". Phys. Rev. Lett. 123 (14): 142501. Bibcode:2019PhRvL.123n2501C. doi:10.1103/PhysRevLett.123.142501. hdl: 10261/204485 . PMID   31702209. S2CID   207940982 . Retrieved 26 March 2020.
  10. ↑ H. N. Liu; A. Obertelli; P. Doornenbal; C. A. Bertulani; G. Hagen; et al. (21 February 2019). "How Robust is the N=34 Subshell Closure? First Spectroscopy of 52Ar". Phys. Rev. Lett. 122 (7): 072502. arXiv: 1811.08451 . Bibcode:2019PhRvL.122g2502L. doi: 10.1103/PhysRevLett.122.072502 . PMID   30848641.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  11. ↑ "IBS launching two HQ Research Centers". Institute for Basic Science . 16 December 2019. Retrieved 10 February 2020.
  12. ↑ "Name: Kevin Insik HAHN" (PDF). IBS-Symposium. Retrieved 28 July 2020.
  13. ↑ "International Advisory Committee". Yukawa Institute for Theoretical Physics . Kyoto University. 2–5 July 2019. Retrieved 10 February 2020.
  14. ↑ "조직도 (Organization) 임원 명단". RAON Users Association (in Korean). Retrieved 11 February 2020.
  15. ↑ Preface: 14th International Symposium on Origin of Matter and Evolution of Galaxies OMEG2017. AIP Conference Proceedings. AIP Conference Proceedings. Vol. 1947. Scitation. 2018. p. 010001. Bibcode:2018AIPC.1947a0001.. doi:10.1063/1.5030803 . Retrieved 11 February 2020.
  16. ↑ List of Committees: 14th International Symposium on Origin of Matter and Evolution of Galaxies OMEG2017. AIP Conference Proceedings. AIP Conference Proceedings. Vol. 1947. Scitation. 2018. p. 010002. Bibcode:2018AIPC.1947a0002.. doi:10.1063/1.5030804 . Retrieved 11 February 2020.
  17. ↑ Nakagawa, Itaru (25–27 March 2019). "Thoughts about Asian Collaboration" (PDF). sPHENIX in Asia Meeting. Brookhaven National Laboratory . Retrieved 10 February 2020.
  18. ↑ "Welcome to ANPhA 2018". ANPhA 2018. Beijing Isotope-Separation-On-Line Neutron-Rich Beam Facility. 13–14 September 2018. Retrieved 10 February 2020.
  19. ↑ "Asian Nuclear Physics Association". Google (in Korean). Asian Nuclear Physics Association. Retrieved 11 February 2020.
  20. ↑ "Advisory Committees - The Science Program Advisory Committee". RAON . Retrieved 11 February 2020.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.