Silicon-28

Silicon-28
Name	Silicon-28
Mass number	28
Nucleons	28
Protons	14
Neutrons	14
Natural abundance	92.223%
Half life	Stable
Spin	0+
Decay modes	Stable

Silicon-28 is the most abundant stable isotope of silicon, comprising the majority of terrestrial and extraterrestrial silicon reservoirs. It plays a central role in semiconductor technology, isotope geochemistry, and precision measurements in nuclear and condensed matter physics. Research on this isotope intersects the work of institutions such as Lawrence Berkeley National Laboratory, CERN, National Institute of Standards and Technology, Max Planck Society, and Los Alamos National Laboratory.

Introduction

Silicon-28 occurs naturally in rocks, meteorites, and planetary mantles studied by teams from Smithsonian Institution, Institut de Physique du Globe de Paris, United States Geological Survey, British Geological Survey, and California Institute of Technology. Its predominance informed early investigations at laboratories like Bell Labs, IBM Research, and AT&T that led to transistor and integrated circuit developments referenced in the histories of Silicon Valley, Stanford University, and Massachusetts Institute of Technology. Geological work connecting isotope ratios used methods pioneered by researchers at Scripps Institution of Oceanography, Max Planck Institute for Chemistry, and University of Cambridge.

Nuclear properties and structure

The nuclide has 14 protons and 14 neutrons, yielding a doubly magic-like closed-shell behavior relevant to nuclear models developed at CERN, Oak Ridge National Laboratory, and Los Alamos National Laboratory. Its ground state is 0+, and theoretical descriptions employ frameworks from groups at Princeton University, Massachusetts Institute of Technology, Institute for Nuclear Theory, and Argonne National Laboratory. Shell-model calculations and ab initio methods used by teams at TRIUMF, RIKEN, and Brookhaven National Laboratory compare observables such as binding energy and charge radius against experimental campaigns at European Organization for Nuclear Research, GSI Helmholtz Centre for Heavy Ion Research, and Paul Scherrer Institute.

Production and enrichment

Commercial enrichment and isotope separation for high-purity samples have been advanced by companies and facilities including Air Liquide, Linde plc, URENCO, Areva, and national programs at Japan Atomic Energy Agency and Russian Federal Nuclear Center. Methods include centrifuge and electromagnetic separation techniques derived from work at Oak Ridge National Laboratory and calutron facilities from the history of Manhattan Project. Chemical processing in cleanrooms at Intel Corporation, TSMC, Micron Technology, and research centers like Lawrence Livermore National Laboratory yields ultrapure silicon materials used in metrology at NIST and PTB (Physikalisch-Technische Bundesanstalt).

Applications and significance

High-purity silicon-28 is critical for quantum computing, where groups at University of New South Wales, University of Chicago, University of California, Berkeley, Harvard University, and Yale University exploit long coherence times for donor spin qubits following protocols from Kane (proposal), experiments at Microsoft Quantum, and collaborations with ColdQuanta. Metrology bodies such as International Bureau of Weights and Measures rely on enriched silicon spheres for determinations related to the redefinition of the SI base units, engaging laboratories like NIST, PTB, and National Metrology Institute of Japan. In astrophysics, isotopic compositions measured by teams at Jet Propulsion Laboratory, European Space Agency, and NASA inform models of solar nebula evolution and are compared to analyses from Meteoritical Society researchers.

Experimental techniques and measurements

Precision experiments use cyclotrons and mass spectrometers at facilities like TRIUMF, ISOLDE, CERN, and Brookhaven National Laboratory to measure nuclear moments, charge radii, and scattering cross sections. Neutron scattering and muon-spin rotation studies at ISIS Neutron and Muon Source, Paul Scherrer Institute, and Oak Ridge National Laboratory probe lattice dynamics and hyperfine interactions relevant to work at IBM Research and Microsoft Research. Cryogenic and ultra-high-purity sample preparation occurs in cleanrooms at Stanford Nanofabrication Facility, MIT.nano, and Center for Nanoscale Science and Technology; measurement campaigns for quantum coherence are coordinated with groups at Duke University, University of Waterloo, and National Taiwan University.

Safety and handling

As a stable, nonradioactive isotope, it poses chemical hazards similar to elemental silicon handled in industrial contexts at plants operated by Intel Corporation, Samsung Electronics, and TSMC. Standard industrial practices follow guidance from agencies such as Occupational Safety and Health Administration, European Chemicals Agency, and Health and Safety Executive for powdered or fine particulate silicon; semiconductor fabrication safety protocols are implemented in fabs at GlobalFoundries and SK Hynix. Environmental monitoring and waste handling adhere to regulations from Environmental Protection Agency, Ministry of the Environment (Japan), and Environment and Climate Change Canada.

Category:Isotopes