[Triumf-seminars] TRIUMF Colloquium today at 11:00

[TRIUMF Seminars]

Date/Time: Mon 2023-04-03 at 11:00

Location:  Auditorium/ hybrid  

Speaker:   Paddy Regan & Richard Brown (University of Surrey/ National Physics Laboratory, UK)

Title:     The Measure of All Things: From quetta to quecto

Abstract: Join Zoom Meeting
https://uvic.zoom.us/j/81149433709?pwd=WWtIelk4ZjNQelBsWFNwNE1IVzl4QT09

Meeting ID: 811 4943 3709
Password: 876142
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An overview of the International Measurement System of Units (SI) will be presented, including the recent revisions of definitions for some of the base units linking them to fundamental constants of nature [1,2,3]. The importance of consistent and traceable measurement of physical quantities will be explained, including concepts of traceability, primary standards and the realisation of SI units. The specific case of traceable measurements for radioactive decays to the becquerel (Bq) will be presented in terms of determining absolute values for isotope-specific radioactive sources using precision measurements of radioactive decay half-lives [4,5,6] - all of which are required for safe and appropriate applications of radioactive materials in areas as diverse as nuclear medicine, energy production, forensics and national security. The presentation will end with a mention of the current largest and smallest prefixes in the SI units which now covers 60 orders of magnitude with example of masses from quetta (Qg) to quecto (qg) grams [7].
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This work is supported by the UK Science and Technologies Facilities Council (STFC) and UK Department for Business, Energy and Industrial Strategy (BEIS) through the National Measurement System (NMS) programme. P.regan at surrey.ac.uk paddy.regan at npl.co.uk

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REFERENCES:
[1] Stock, M., et al., "The revision of the SI - the result of three decades of progress in metrology"; Metrologia, 56(2), p.022001 (2019); https://doi.org/10.1088/1681-7575/ab28a8                                                         
[2] Brown, RJC, "A metrological approach to quantities that are counted and the unit one."; Metrologia, 58(3), p.035014.(2021); https://doi.org/10.1088/1681-7575/abf7a4
[3] Guettler, et al., "Amount of substance and the mole in the SI"; Metrologia, 56(4), p.044002.(2019) https://doi.org/10.1088/1681-7575/ab1fae                                                            
[4] Regan, P.H., et al.,  "Radionuclide metrology and standards in nuclear physics". Nuclear Physics News, 28(3), pp.25-29 (2018); https://doi.org/10.1080/10619127.2018.1495482                                                                     
[5] Collins, S.M.,  et al., "Investigation of coincidence counting using the National Nuclear Array (NANA) as a primary standard", Appl. Rad. and Isotopes 134, 290 (2018); https://doi.org/10.1016/j.apradiso.2017.07.056                                                         
[6] Collins, S.M., et al., "Determination of the 161Tb half-life", . Appl. Rad. and Isotopes 182, 110140 (