1. Thailand Institute of Nuclear Technology (Public Organization), Nakhon Nayok, Thailand
2. Nuclear Chemistry Division, Spiez Laboratory, Federal Office for Civil Protection, Spiez, Switzerland
3. Department of Groundwater Resources, Ministry of Natural Resources and Environment, Bangkok, Thailand
4. Isotope Hydrology Laboratory, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
5. Physics Division, Argonne National Laboratory, Lemont, IL, USA