Dr. Weihua Zhang

Adjunct Research Professor
Radiation Protection Bureau - Health Canada
775 Brookfield Road, AL 6302D,
Ottawa, Ontario K1A 1C1
Tel: 
(613) 952-4629
Email: 
weihua [dot] zhangathc-sc [dot] gc [dot] ca

Research

I have a long-standing interest in the methodological development for identification and quantification of trace amounts of fission/activation products in environmental samples, which are often of primary importance for understanding and characterization of nuclear and radiological events in various area including nuclear power plant accidents, detection of clandestine nuclear tests in the Comprehensive Nuclear-Test-Ban Treaty (CTBT) regime, nuclear forensic and environmental studies.

At present, a dual-Germanium radiation detection spectrometer has been recently developed at Radiation Protection Bureau (RPB) to enhance Canada's contribution and commitment to CTBT. With a pair of well-shielded detectors face-to-face, the system features of low background and high detection efficiency. Our newly designed system outperforms the conventional ground level detectors, by reducing cosmic-muon and natural radionuclide induced background signal.

By further employing a gamma-gamma or/and beta-gamma coincidence detection technique, the detection capabilities on trace radioactivity will be largely improved. This is going to be a several-year project, in which Monte Carlo simulations with Geant4, data analysis with ROOT and routine calibrations and sample measurements are needed. 


Selected Publications

 

1. Weihua Zhang, Kurt Ungar, Chuanlei Liu and Maverick Mailhot (2016) Cosmic-muon intensity measurement and overburden estimation in a building at surface level and in an underground facility using two BC408 scintillation detectors coincidence counting system, Journal of Environmental Radioactivity 162-163: 340-346..

 

2. Jing Chen, Baki Sadi, Weihua Zhang, Nadereh St-Amant and Michael D. Rennie (2016) A study on the levels of radioactivity in fish samples from the experimental lakes area in Ontario, Canada, Journal of Environmental Radioactivity 153, 222-230.

 

3. Cook MC, Stukel MJ, Zhang Weihua, Mercier JF, Cooke MW (2015) The determination of Fukushima-derived cesium-134 and cesium-137 in Japanese green tea samples and their distribution subsequent to simulated beverage preparation, Journal of Environmental Radioactivity 153, 23-30.

 

4. Weihua Zhang, Jing Chen, Kurt Ungar and Michael Cooke (2015) Estimation of the Arctic aerosols from local and long-range transport using relationships between 210Pb and 212Pb atmospheric activity concentrations Journal of Environmental Radioactivity 141, 123-129.

 

5. Jing Chen, Weihua Zhang, Baki Sadi, (2015) A report of radioactivity measurements of freshwater fish samples from the National Capital Region of Canada, Journal of Environmental Radioactivity, DOI: 10.1016/j.jenvrad.2015.02.005.

 

6. Weihua Zhang, Kurt Ungar, Matthew Stukel, Pawel Mekarski, (2014) A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic 22Na/7Be activity ratio measurement, Journal of Environmental Radioactivity, 130, 1-6.

 

7. Weihua Zhang, A. Chatt, (2014) Anticoincidence counting further improves detection limits of short-lived products by pseudo-cyclic instrumental neutron activation analysis, J Radioanal Nucl Chem, DOI 10.1007/s10967-014-3540-0.

 

8. Weihua Zhang, A. Chatt, (2014) Evaluation of INAA–anticoincidence counting for measuring nanogram levels of vanadium in relatively high-salt nutritional reference materials, Journal of Radioanalytical and Nuclear Chemistry,  299( 3), 1777-1785.

 

9. Weihua Zhang, Benjamin Keeshan, Pawel Mekarski, Jing Yi, Kurt Ungar, (2013) Performance evaluation and optimization for a newly developed digital list-mode data acquisition Compton suppression spectrometer,  Applied Radiation and Isotopes, 81 : 96-102.

 

10. W. Zhang,  A. Chatt, (2013) Epithermal instrumental neutron activation analysis in conjunction with anti-coincidence gamma-ray spectrometry for investigating iodine levels in Canadian foods, Journal of Radioanalytical and Nuclear Chemistry,  296 , 495-501.

 

11. Ian Hoffman, Ed Korpach, Pawel Mekarski, Kurt Ungar,  Jing Yi, Weihua Zhang, Mikael Moring, Vladimir Khotylev, Ali El-Jab, (2013) Fukushima event reconstruction using modelling and isotope relationships, Journal of Radioanalytical and Nuclear Chemistry,  296( 2) , 1091-1098.

 

12. Weihua Zhang, Benjamin Keeshan, Pawel Mekarski, Jing Yi and Kurt Ungar, (2013) Performance evaluation and optimization for a newly developed digital list-mode data acquisition Compton suppression spectrometer, Applied Radiation and Isotopes, http://dx.doi.org/10.1016/j.apradiso.2013.02.002.

 

13. Weihua Zhang, Ed Korpach, Rodney Berg and Kurt Ungar, (2013) Testing of an automatic outdoor gamma ambient dose-rate surveillance system in Tokyo and its calibration using measured deposition after the Fukushima nuclear accident, Journal of Environmental Radioactivity, http://dx.doi.org/10.1016/j.jenvrad.2012.12.011.

 

14. Weihua Zhang, Judah Friese and Kurt Ungar, (2013) The ambient gamma dose-rate and the inventory of fission products estimations with the soil samples collected at Canadian embassy in Tokyo during Fukushima nuclear accident, J Radioanal Nucl Chem, 296:69–73.

 

15. Jing Chen, Weihua Zhang, Austin Jiao, (2012) An Extended Study on the Correlation between 210Pb in Household Dust and Indoor Radon Concentration, Environment and Pollution, Vol. 1 (2), 70-74.

 

16. Ian Hoffman, Ed Korpach,,Pawel Mekarski,,Kurt Ungar,,Jing Yi, Weihua Zhang, Mikael Moring, Vladimir Khotylev, Ali El-Jaby, (2012) Fukushima event reconstruction using modelling and isotope relationships, J Radioanal Nucl Chem, DOI 10.1007/s10967-012-2124-0.

 

17. Weihua Zhang, Pawel Mekarski, Marc Bean, Jing Yi, and Kurt Ungar, (2012) Modelling of a Single-Channel Beta–Gamma Coincidence Phoswich Detector Using Geant4 for the Conversion Electron Energy Peak Resolution and Beta–Gamma Coincidence Efficiency Improvement, Pure Appl. Geophys, DOI 10.1007/s00024-012-0494-4.

 

18. Weihua Zhang, A. Chatt, (2012) Epithermal instrumental neutron activation analysis in conjunction with anti-coincidence gamma-ray spectrometry for investigating iodine levels in Canadian foods, J Radioanal Nucl Chem DOI 10.1007/s10967-012-2064-8.

 

19. Weihua Zhang, Pawel Mekarski , Maxime Dion , Jing Yi,  Kurt Ungar, (2012) A digital Compton suppression spectroscopy without gamma-ray coincidence-summing loss using list-mode multispectral data acquisition,  J Radioanal Nucl Chem, 292: 1265-1272.

 

20. Thomas, Patricia A.; Anderson, Darwin W.; Zhang, Weihua; Baweja, Anar S; Tracy, Bliss L., (2011) Radon Emanation in Saskatchewan Soils,  Health Physics, 100( 6):  565-573.

 

21. Zhang Weihua, Yi J, Mekarski P, Ungar K, Hauck B, Kramer GH, (2011) Quantification of 235U and 238U activity concentrations for undeclared nuclear materials by a digital gamma-gamma coincidence spectroscopy. Appl Radiat Isot., 69(6): 904-907.

 

22. Weihua Zhang, Pawel Mekarski, Marc Bean, Jing Yi, and Kurt Ungar, (2011) An Optimized Design of Single-Channel Beta-Gamma Coincidence Phoswich Detector by Geant4 Monte Carlo Simulations, Journal of Science and Technology of Nuclear Installations, 2011: Article ID 741396. pagesdoi:10.1155/2011/741396.

 

23. Weihua Zhang, Marc Bean, Mike Benotto, Jeff Cheung, Kurt Ungar, Brian Ahier, (2011) Development of a new aerosol monitoring system and its application in Fukushima nuclear accident related aerosol radioactivity measurement at the CTBT radionuclide station in Sidney of Canada,  Journal of Environmental Radioactivity, 102: 1065-1069.

 

24. Weihua Zhang, Yi, J., Mekarski, P., Hoffman, I. and Ungar, K., (2011) A system for low-level cosmogenic 22Na radionuclide measurement by gamma-gamma coincidence method using BGO detectors, Journal of Radioanalytical and Nuclear Chemistry, 287(2), 551-555.

 

25. Weihua Zhang, Yi, J., Mekarski, P., Ungar, K., Hauck, B. and Kramer, H.G., (2010) A gamma-gamma coincidence spectrometric method for rapid uranium isotopic fingerprints characterization, Journal of Radioanalytical and Nuclear Chemistry, DOI: 10.1007/s10967-010-0868-y.

 

26. Weihua Zhang, Yi, J., Mekarski, P., Hoffman, I. and Ungar, K., (2010) A system for low-level cosmogenic 22Na radionuclide measurement by gamma-gamma coincidence method using BGO detectors, Journal of Radioanalytical and Nuclear Chemistry, DOI 10.1007/s10967-010-0758-3.

 

27. Weihua Zhang, Pawel Mekarski, Jonathan Lam and Kurt Ungar, (2010) A Geant4 Monte Carlo method for synthesizing radioxenon beta-gamma coincidence spectra” Journal of Radioanalytical and Nuclear Chemistry, 286 (1), 235-240.

 

28. Weihua Zhang, Pawel Mekarski and Kurt Ungar, (2010) Beta-gamma coincidence counting efficiency and energy resolution optimization by Geant4 Monte Carlo simulations for a phoswich well detector, Applied Radiation and Isotopes, 68(12), 2377-2381.

 

29. Weihua Zhang, Pawel Mekarski, Jonathan Lam, Kurt Ungar and Eric Pellerin, (2010) Geant4 Monte Carlo radioxenon beta-gamma coincidence efficiency simulation for a phoswich detector, Journal of Radioanalytical and Nuclear Chemistry, 285 (3), 475-482.

 

30. Weihua Zhang, Jarmo Ala-Heikkila, Kurt Ungar, Ian Hoffman and Ryan Lawrie, (2010) Automated analysis for large amount of gaseous fission product gamma-scanning spectra from nuclear power plant and its data mining, J. Radioanal Nucl Chem, (284) 647–651.