©2020 Biological and Chemical Oceanography Data Management Office.Funded by the U.S. National Science Foundation
Low-level beta detectors manufactured by Riso (now Nutech) in Denmark. These instruments accept samples that can be mounted on a 25mm filter holder. These detectors have very low backgrounds, 0.17 counts per minute, and can have counting efficiencies as high as 55%.
Typically used in laboratory analyses. Designed to measure low levels of beta particle emission. The systems work on the principle of anticoincidence.
| Dataset Name | PI-Supplied Description | PI-Supplied Name |
|---|---|---|
| 234Th flux in epipelagic waters at Station ALOHA and the Equatorial Pacific from R/V Kilo Moana cruises KM1407, KM1418, & KM1515 during 2014-2015 | Thorium counts were made using a low level RISO beta counter within 2 weeks of sample collection. | RISO beta counter |
| Seawater radioisotope (234Th) and carbon from sampling conducted at the Compass Station in Bedford Basin, Nova Scotia, Canada from April to August 2019 | 234Th samples were analyzed using a Riso Anti-coincidence Beta Counter. | Riso Laboratory Anti-coincidence Beta Counters |
| Activities of size-fractionated particulate thorium isotopes and total Thorium-234 from the U.S. GEOTRACES Arctic cruise, HLY1502, on USCGC Healy from August to October 2015 | Samples were analyzed using a Riso Anti-coincidence Beta Counter. | Riso Anti-coincidence Beta Counter |
| Water column total and particulate Thorium-234 from Leg 1 (Seattle, WA to Hilo, HI) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1814) on R/V Roger Revelle from September to October 2018 | Efficiency Calibrations: The detectors are intercalibrated with each other and across the transect using high-energy U standards. Limits of Detection: Limits of detection are not reported because they are not applicable to the 234Th beta counting method. A 'non-detect' for 234Th or a case where there is no 234Th present (initially or after 6 months of decay) will still result in a measurable amount of background radioactivity due to the beta decay of long-lived natural radionuclides that are also present. These background values are utilized and therefore, they are not reported as non-detections of 234Th. | |
| Water column total and particulate Thorium-234 from Leg 2 (Hilo, HI to Papeete, French Polynesia) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1815) on R/V Roger Revelle from October to November 2018 | Efficiency Calibrations: The detectors are intercalibrated with each other and across the transect using high-energy U standards. Limits of Detection: Limits of detection are not reported because they are not applicable to the 234Th beta counting method. A 'non-detect' for 234Th or a case where there is no 234Th present (initially or after 6 months of decay) will still result in a measurable amount of background radioactivity due to the beta decay of long-lived natural radionuclides that are also present. These background values are utilized and therefore, they are not reported as non-detections of 234Th. | |
| Particulate Th-234 from in-situ pumps, including large size fraction (> 51 um) and small size fraction (1-51 um), from R/V Thomas G. Thompson cruise TN303 in the Eastern Tropical Pacific in 2013 (U.S. GEOTRACES EPZT project) | 234Th samples were analyzed using a Riso Anti-coincidence Beta Counter using a helium/1% butane mixture. | Riso Laboratory Anti-coincidence Beta Counters |
| Water-column total Th-234 from R/V Thomas G. Thompson cruise TN303 in the Eastern Tropical Pacific in 2013 (U.S. GEOTRACES EPZT project) | Th-234 samples were analyzed using a Riso Anti-coincidence Beta Counter using a helium/1% butane mixture. | RISO Laboratory Anti-coincidence Beta Counters |
| Water-column total Thorium-234 and Uranium-238 from R/V Knorr cruises KN199-04 and KN204-01 in the Subtropical northern Atlantic Ocean from 2010-2011 (U.S. GEOTRACES NAT project) | Th-234 samples were analyzed using a Riso Anti-coinicidence Beta Counter using a helium/1% butane mixture. | Riso Laboratory Anti-coincidence Beta Counters |
| TPC, PIC, POC, TPN, and Th-234 from in-situ pumps at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) site in the Northeast Atlantic Ocean during RRS Discovery cruise DY077 in April of 2017 | Riso Beta Counter | |
| Particulate Th data from samples collected on 5 cruises at Station ALOHA off Hawaii and Station M off California from 2019 to 2020 | low level RISO Beta Counter | |
| Particulate Th-234 collected using large volume McLane pumps (LVPs) as part of the EAGER chief scientist training cruise (KM1910) at Station ALOHA, subtropical North Pacific gyre in June 2019 | Low-level beta detectors manufactured by Risø (now Nutech) in Denmark. These instruments accept samples that can be mounted on a 25mm filter holder. These detectors have very low backgrounds, 0.17 counts per minute, and can have counting efficiencies as high as 55%. Efficiency Calibrations: The detectors are intercalibrated with each other and across the transect using low-energy U standards. Limits of Detection: Limits of detection are not reported because they are not applicable to the 234Th beta counting method. A ‘non-detect’ for 234Th or a case where there is no 234Th present (initially or after 6 months of decay) will still result in a measurable amount of background radioactivity due to the beta decay of long lived natural radionuclides that are also present. These background values are utilized and therefore, they are not reported as a non-detections of 234Th. See: https://cafethorium.whoi.edu/services/ and https://www.nutech.dtu.dk/english/products-and-services/radiation-instruments/gm_multicounter | |
| Particulate Th-234 collected with surface-tethered sediment traps at Station ALOHA as part of the EAGER chief scientist training cruise (KM1910) in the subtropical North Pacific gyre in June 2019 | Low-level beta detectors manufactured by Risø (now Nutech) in Denmark. These instruments accept samples that can be mounted on a 25mm filter holder. These detectors have very low backgrounds, 0.17 counts per minute, and can have counting efficiencies as high as 55%. Efficiency Calibrations: The detectors are intercalibrated with each other and across the transect using low-energy U standards. Limits of Detection: Limits of detection are not reported because they are not applicable to the 234Th beta counting method. A ‘non-detect’ for 234Th or a case where there is no 234Th present (initially or after 6 months of decay) will still result in a measurable amount of background radioactivity due to the beta decay of long lived natural radionuclides that are also present. These background values are utilized and therefore, they are not reported as a non-detections of 234Th. See: https://cafethorium.whoi.edu/services/ and https://www.nutech.dtu.dk/english/products-and-services/radiation-instruments/gm_multicounter | |
| Carbon, Nitrogen, biogenic silica, thorium-234, and mass fluxes from upper ocean sediment traps at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) site in the Northeast Atlantic Ocean during RRS Discovery cruise DY077 in April of 2017 | Riso Beta Counter | |
| Water column Th-234 activity determined using a 4-L technique from samples collected on R/V Melville cruise MV1008 in the Costa Rica Dome in 2010 (CRD FLUZiE project) | Samples were beta counted at the University of South Carolina on a RISO low-level beta multi-counter within two months of the collection date. | RISO low-level beta multi-counter |
| Samples were beta counted on a RISO low-level background beta counter | RISO low-level GM beta multi-counter | |
| Thorium-234 data from SalpPOOP cruise on the R/V Tangaroa to the Chatham Rise (subtropical and subantarctic waters) in October and November 2018 | RISO low-level beta multi-counter | |
| Total Th data from samples collected on 5 cruises at Station ALOHA off Hawaii and Station M off California from 2019 to 2020 | low level RISO Beta Counter | |
| Water column Th-234 activities from 4-liter water samples at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) site in the Northeast Atlantic Ocean during RRS Discovery cruise DY077 in April of 2017 | Riso Beta Counter |
©2020 Biological and Chemical Oceanography Data Management Office.