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Jason Singh Walia (Fed)

Jason Singh Walia is a Physicist in the Dosimetry Group, Radiation Physics Division of the NIST Physical Measurement Laboratory with expertise in performing sealed source x-ray, gamma-ray and electron dosimetry measurements.

Jason is the lead scientist in charge of maintaining and disseminating the national, primary air-kerma strength standard for low energy photon-emitting encapsulated sources used in prostate brachytherapy. His work involves calibration and characterization of small radioactive “seed” sources using the NIST Wide-Angle Free-Air Chamber (WAFAC), including well-ionization chamber response, emergent x-ray spectra and anisotropy emission measurements of various model sources. Jason’s brachytherapy seed efforts at NIST are required to standardize quality assurance and calibration, and to maintain the dosimetric traceability of sources to ensure accurate clinical dosimetry.

Jason is also the lead scientist for beta particle dosimetry measurements at NIST. His work involves calibrating user-owned encapsulated beta-particle sources and standard laboratory transfer instruments for applications in radiation protection. An extrapolation ionization chamber is used to provide an absolute measurement of absorbed dose-rate to water establishing traceability for organizations such as the U.S. Army, Navy, Department of Energy (DOE) and other national laboratories that require accurate knowledge of beta radiation exposure to personnel.

Jason is currently a member of the American Association of Physicists in Medicine (AAPM) and the AAPM Working Group on Brachytherapy Dosimetry (WGBD).

Created October 3, 2019, Updated August 2, 2023