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Active Radiometric Calorimeter for Absolute Radioactive Source Calibration



Kurt E. Stump, Larry DeWerd, David A. Rudman, Susan A. Schima


This report describes the design and initial noise 'oor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise 'oor of approximately 2 nW. This low noise 'oor is achieved by using High Temperature Superconducting (HTS) Transition Edge Sensors (TES) thermometers in a temperature control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are its ability to change sources for calibration without disrupting the vacuum of the instrument and the ability to measure the emitted power of a source in addition to the total contained source power.
Review of Scientific Instruments


calorimeter, high temperature superconductors, radioactive sources


Stump, K. , DeWerd, L. , Rudman, D. and Schima, S. (2005), Active Radiometric Calorimeter for Absolute Radioactive Source Calibration, Review of Scientific Instruments, [online], (Accessed April 16, 2024)
Created March 1, 2005, Updated October 12, 2021