The Next Generation of Current Measurement for Ionization Chambers
Ryan P. Fitzgerald, Denis E. Bergeron, Dean G. Jarrett, Neil M. Zimmerman, Carine Michotte, Hansjoerg Scherer, Stephen Giblin, Steven Judge
Re-entrant ionization chambers (ICs) are essential to radionuclide metrology and nuclear medicine for maintaining standards and measuring half-lives. Metrology-quality systems must be precise and stable to 0.1% over many years, and linear from 10^(-14) A to 10^(-8) A. Thus, labs depend on bespoke current measurement systems and often rely on sealed sources to generate reference currents. To maintain and improve present capabilities, metrologists need to overcome two looming challenges: ageing electronics and decreasing availability of sealed sources. Possible solutions using Ultrastable Low-Noise Current Amplifiers (ULCAs), resistive-feedback electrometers, and (quantum) single-electron pumps are reviewed. Broader discussions of IC design and methodology are discussed. ULCAs show promise and resistive-feedback systems which take advantage of standard resistor calibrations offer an alternative.
, Bergeron, D.
, Jarrett, D.
, Zimmerman, N.
, Michotte, C.
, Scherer, H.
, Giblin, S.
and Judge, S.
The Next Generation of Current Measurement for Ionization Chambers, Applied Radiation and Isotopes, [online], https://doi.org/10.1016/j.apradiso.2020.109216
(Accessed May 16, 2021)