Instrument: Radium Delayed Coincidence Counter

Instrument Short Name: RaDeCC
Instrument Description:

The RaDeCC is an alpha scintillation counter that distinguishes decay events of short-lived radium daughter products based on their contrasting half-lives. This system was pioneered by Giffin et al. (1963) and adapted for radium measurements by Moore and Arnold (1996).

References:
Giffin, C., A. Kaufman, W.S. Broecker (1963). Delayed coincidence counter for the assay of actinon and thoron. J. Geophys. Res., 68, pp. 1749-1757.
Moore, W.S., R. Arnold (1996). Measurement of 223Ra and 224Ra in coastal waters using a delayed coincidence counter. J. Geophys. Res., 101 (1996), pp. 1321-1329.
Charette, Matthew A.; Dulaiova, Henrieta; Gonneea, Meagan E.; Henderson, Paul B.; Moore, Willard S.; Scholten, Jan C.; Pham, M. K. (2012). GEOTRACES radium isotopes interlaboratory comparison experiment. Limnology and Oceanography - Methods, vol 10, pg 451.

PI supplied instrument name: Radium Delayed Coincidence Counter (RaDeCC)
Dataset-specific description

Discrete seawater, groundwater, lake, and river water samples were collected from Kasitsna Bay and Toolik Lake in August 2011 and July 2012 and the Beaufort Sea August 2012. Groundwater samples were collected in all locations from freshly dug pits or temporary PVC well points of variable depth depending on the depth of the water table. All water samples were collected by submersible pump. Sample water was passed through a plastic column containing manganese dioxide impregnated acrylic fiber at a rate of <2 L/min for collection of Ra isotopes (Moore 2008). Samples were shipped to the University of California Santa Cruz for Analysis on a Radium Delayed Coincidence Counter (RaDeCC) for measurement of Ra-223 and Ra-224 activities within less than 5 days (Moore and Arnold 1996). The fibers were analyzed on the RadeCC again 3-5 weeks after collection to correct for Th-228 supported Ra-224, and one year after collection for Ra-228 (Moore 2008; Young et al. 2008). Standards were run on a monthly basis as part of the quality control for maintenance of the instrument and analytical errors calculated using established methods and were less than 10% (Garcia-Solsona et al. 2008).