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Michael P. Unterweger (Assoc)

Joining NIST (then NBS) in 1972 as a Presidential Intern, Mike quickly became internationally recognized for his experimental work in radioactivity measurements and preparation of radioactive standards, and is considered by the international radionuclide metrology community as one of the world's experts in radioactive gas measurements.

As such a well-known expert in radionuclide metrology, Mike was the logical choice to lead the Radioactivity Group when the Group Leader was detailed to the Division office in March 2003. His wide-ranging experience, gained over nearly three decades in the field, provides him with a unique perspective on the needs and opportunities in the Group. The Radioacitivity Group is responsible for a wide range of programs, e.g. low-level standards for environmental measurements and monitoring, standards for nuclear medicine, standards and testing criteria for radiological instrumentation used for homeland security, and radionuclide metrology.

When, five years later in 2008, the Group Leader became Division Chief, "acting" was removed and Mike became Group Leader in title as well as in deed. As Group Leader, he has managed the activities and personnel of this diverse group on a daily basis, and maintains the Radioactivity Group as one of the preeminent radiometrology organizations in the world. Since September 2001, Mike has also taken on the key leadership role in the development of National standards for homeland security radioactivity measurements, providing early responders and industry with equipment and procedures to reliably detect, prevent and respond to a radiological event.


Ambient humidity, the overlooked influencer of radioactivity measurements

Stefaan Pomme, Michael P. Unterweger, Ryan P. Fitzgerald, Denis E. Bergeron, Leticia Pibida, International Collaboration
When verifying the validity of the exponential-decay law through 128 precise decay rate measurement series at various nuclear laboratories, minor violations

Uncertainties in Internal Gas Counting

Michael P. Unterweger, L Johansson, M Rodriques, A Yunoki, Lisa R. Karam
The uncertainties in internal gas counting can, for the most part, be split into two areas: counting and sample gas measurement uncertainties and the counting
Created October 3, 2019, Updated December 8, 2022