Eric B. Norman | |
---|---|
Born | |
Nationality | American |
Occupation(s) | Physicist, academic and researcher |
Awards | Outstanding Performance Award, Lawrence Berkeley Laboratory Fellow, American Physical Society Outstanding Mentor Award, U. S. Department of Energy Fellow, American Association for the Advancement of Science Co-Recipient of Breakthrough Prize in Fundamental Physics For participation in the Sudbury Neutrino Observatory |
Academic background | |
Education | A. B. in Physics S. M. in Physics Ph. D. in Physics |
Alma mater | Cornell University University of Chicago |
Academic work | |
Institutions | University of California,Berkeley |
Eric B. Norman is an American physicist. He is a professor in the graduate school of the University of California,Berkeley. [1]
He has conducted research on neutrino physics,astrophysics,and on the applications of nuclear science for homeland security and non-proliferation. He is also the co-discoverer of 4 isotopes (57Cr,59Mn,60Mn,67As). [2]
He is a fellow of the American Physical Society [3] and of the American Association for the Advancement of Science, [4] and a member of American Nuclear Society. [5] He is a reviewer of research proposals for United States Department of Energy,for the National Science Foundation and for the Natural Sciences and Engineering Research Council of Canada. Since 1995,he has been a co-developer of nuclear science wallchart and a member of the Contemporary Physics Education Project. [1]
He received a bachelor's degree in physics from Cornell University in 1972,and then a master's degree in physics in 1974 and a PhD in nuclear astrophysics in 1978,both from the University of Chicago. His doctoral thesis (mentored by David Schramm and Cary Davids) involved theoretical studies of r-process nucleosynthesis and the discovery of new radioactive isotopes (57Cr,59Mn,60Mn,and 67As). [6]
His research focuses on low-energy experimental nuclear physics,nuclear security,and medical applications of nuclear science. [7]
Norman conducted multiple experiments involving measurements of cross sections for reactions important for understanding the synthesis of elements in stars. He also led research focused on the impacts of high temperatures,and densities that occur in various astrophysical environments on the decay rates of key radioactive species such as 26Al,44Ti,54Mn, [8] and 176Lu. In another study,he demonstrated reaction rate sensitivity of 44Ti production in massive stars and highlighted the implications of a thick target yield measurement of 40Ca(α,γ)44Ti.
Norman has worked extensively on two aspects of neutrino physics,the solar neutrino problem, [9] [10] and searches for neutrinoless double beta decay. [11] In the late 1980s and early 1990s,he led a group at Lawrence Berkeley National Laboratory in its participation in the Sudbury Neutrino Observatory. [12] His group designed and built the large geodesic structure that supported the nearly 10,000 photomultiplier tubes that were used to observe Cherenkov light from neutrino interactions in the D2O (heavy water) target. [13] He,along with co-workers also designed and built several devices that were used to accurately determine the energy calibration of the detector and also its neutron detection efficiency. [14] SNO ultimately solved the solar neutrino problem by demonstrating that two thirds of the electron-type neutrinos produced through fusion reactions in the Sun oscillate into mu- and/or tau- neutrinos before reaching the Earth. This measurement led to the awarding of the 2015 Nobel Prize in physics and the 2015 Breakthrough Prize in Fundamental Physics. [15]
Since 1998 Norman and his group have been involved in the Cryogenic Underground Observatory for Rare Events (CUORE). [16] This experiment is designed to search for the neutrinoless double beta decay of 130Te,which can only occur if neutrinos have finite masses and if neutrinos are their own anti-particles. [17] Observation of this decay mode could help to explain the origin of the matter/anti-matter asymmetry of the universe. This experiment is located in the Gran Sasso National Laboratory in Italy and utilizes approximately 1000 5x5x5-cm crystals of TeO2 operated as cryogenic bolometers at a temperature of approximate 10 mK. [18]
In 2002,Norman worked at the Lawrence Livermore National Laboratory,and became involved in a project focused on screening cargo containers for special nuclear material –that is 235U or 239Pu. [19] While working there,he along with his colleagues devised a scheme using fast neutrons to irradiate the cargo and then to look for high energy beta-delayed gamma rays emitted by fission products as the signature. [20] Subsequently,his group has worked on a number of experiments in nuclear forensics designed to determine the nature and/or origins of a variety of nuclear materials. [21]
A neutrino is a fermion that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles. The weak force has a very short range,the gravitational interaction is extremely weak due to the very small mass of the neutrino,and neutrinos do not participate in the electromagnetic interaction or the strong interaction. Thus,neutrinos typically pass through normal matter unimpeded and undetected.
The Sudbury Neutrino Observatory (SNO) was a neutrino observatory located 2100 m underground in Vale's Creighton Mine in Sudbury,Ontario,Canada. The detector was designed to detect solar neutrinos through their interactions with a large tank of heavy water.
In particle physics,majorons are a hypothetical type of Goldstone boson that are conjectured to mediate the neutrino mass violation of lepton number or B −L in certain high energy collisions such as
Jack Steinberger was a German-born American physicist noted for his work with neutrinos,the subatomic particles considered to be elementary constituents of matter. He was a recipient of the 1988 Nobel Prize in Physics,along with Leon M. Lederman and Melvin Schwartz,for the discovery of the muon neutrino. Through his career as an experimental particle physicist,he held positions at the University of California,Berkeley,Columbia University (1950–68),and the CERN (1968–86). He was also a recipient of the United States National Medal of Science in 1988,and the Matteucci Medal from the Italian Academy of Sciences in 1990.
A solar neutrino is a neutrino originating from nuclear fusion in the Sun's core,and is the most common type of neutrino passing through any source observed on Earth at any particular moment. Neutrinos are elementary particles with extremely small rest mass and a neutral electric charge. They only interact with matter via the weak interaction and gravity,making their detection very difficult. This has led to the now-resolved solar neutrino problem. Much is now known about solar neutrinos,but the research in this field is ongoing.
In nuclear physics,double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons,or vice versa,inside an atomic nucleus. As in single beta decay,this process allows the atom to move closer to the optimal ratio of protons and neutrons. As a result of this transformation,the nucleus emits two detectable beta particles,which are electrons or positrons.
Neutrinoless double beta decay (0νββ) is a commonly proposed and experimentally pursued theoretical radioactive decay process that would prove a Majorana nature of the neutrino particle. To this day,it has not been found.
T2K is a particle physics experiment studying the oscillations of the accelerator neutrinos. The experiment is conducted in Japan by the international cooperation of about 500 physicists and engineers with over 60 research institutions from several countries from Europe,Asia and North America and it is a recognized CERN experiment (RE13). T2K collected data within its first phase of operation from 2010 till 2021. The second phase of data taking (T2K-II) is expected to start in 2023 and last until commencement of the successor of T2K –the Hyper-Kamiokande experiment in 2027.
Borexino is a deep underground particle physics experiment to study low energy (sub-MeV) solar neutrinos. The detector is the world's most radio-pure liquid scintillator calorimeter and is protected by 3,800 meters of water-equivalent depth. The scintillator is pseudocumene and PPO which is held in place by a thin nylon sphere. It is placed within a stainless steel sphere which holds the photomultiplier tubes (PMTs) used as signal detectors and is shielded by a water tank to protect it against external radiation. Outward pointing PMT's look for any outward facing light flashes to tag incoming cosmic muons that manage to penetrate the overburden of the mountain above. Neutrino energy can be determined through the number of photoelectrons measured in the PMT's. While the position can be determined by extrapolating the difference in arrival times of photons at PMT's throughout the chamber.
The solar neutrino problem concerned a large discrepancy between the flux of solar neutrinos as predicted from the Sun's luminosity and as measured directly. The discrepancy was first observed in the mid-1960s and was resolved around 2002.
A geoneutrino is a neutrino or antineutrino emitted in decay of radionuclide naturally occurring in the Earth. Neutrinos,the lightest of the known subatomic particles,lack measurable electromagnetic properties and interact only via the weak nuclear force when ignoring gravity. Matter is virtually transparent to neutrinos and consequently they travel,unimpeded,at near light speed through the Earth from their point of emission. Collectively,geoneutrinos carry integrated information about the abundances of their radioactive sources inside the Earth. A major objective of the emerging field of neutrino geophysics involves extracting geologically useful information from geoneutrino measurements. Analysts from the Borexino collaboration have been able to get to 53 events of neutrinos originating from the interior of the Earth.
Kam-Biu Luk is a professor of physics,with a focus on particle physics,at UC Berkeley and a senior faculty scientist in the Lawrence Berkeley National Laboratory's physics division. Luk has conducted research on neutrino oscillation and CP violation. Luk and his collaborator Yifang Wang were awarded the 2014 Panofsky Prize "for their leadership of the Daya Bay experiment,which produced the first definitive measurement of θ13 angle of the neutrino mixing matrix." His work on neutrino oscillation also received 2016 Breakthrough Prize in Fundamental Physics shared with other teams. He also received a Doctor of Science honoris causa from the Hong Kong University of Science and Technology in 2016. Luk is a fellow of the American Physical Society,and the American Academy of Arts and Sciences.
Herbert Hwa-sen Chen was a theoretical and experimental physicist at the University of California at Irvine known for his contributions in the field of neutrino detection. Chen's work on observations of elastic neutrino-electron scattering provided important experimental support for the electroweak theory of the standard model of particle physics. In 1984 Chen realized that the deuterium of heavy water could be used as a detector that would distinguish the flavors of solar neutrinos. This idea led Chen to develop plans for the Sudbury Neutrino Observatory that would eventually make fundamental measurements demonstrating that neutrinos were particles with mass.
Eugene William Beier is an American physicist.
Karsten M. Heeger is a German–American physicist and Eugene Higgins Professor of Physics at Yale University,where he also serves as both chair of the Yale Department of Physics and director of Wright Laboratory. His work is primarily in the area of neutrino physics,focusing on the study of neutrino oscillations,neutrino mass,and dark matter.
Jocelyn Monroe is an American British experimental particle physicist who is a professor at the University of Oxford. Her research considers the development of novel detectors as part of the search for dark matter. In 2016 she was honoured with the Breakthrough Prize in Fundamental Physics for her work on the Sudbury Neutrino Observatory.
Daniel S. Akerib is an American particle physicist and astrophysicist. He was elected in 2008 a fellow of the American Physical Society (APS).