©2020 Biological and Chemical Oceanography Data Management Office.Funded by the U.S. National Science Foundation
©2020 Biological and Chemical Oceanography Data Management Office.Germanium detectors are semiconductor diodes having a p-i-n structure in which the intrinsic (i) region is sensitive to ionizing radiation, particularly x rays and gamma rays. Under reverse bias, an electric field extends across the intrinsic or depleted region. When photons interact with the material within the depleted volume of a detector, charge carriers (holes and electrons) are produced and are swept by the electric field to the p and n electrodes. This charge, which is in proportion to the energy deposited in the detector by the incoming photon, is converted into a voltage pulse by an integral charge sensitive preamplifier. Germanium detectors are mostly used for gamma spectroscopy in nuclear physics, as well as x-ray spectroscopy.
| Dataset Name | PI-Supplied Description | PI-Supplied Name |
|---|---|---|
| Carbon content and radioisotope data from sampling conducted at the Compass Station in Bedford Basin, Nova Scotia, Canada from February to August 2019 | All gamma counting of sediments (for Thorium and associated radioisotopes) was completed using Canberra Intrinsic High Purity Germanium Detectors owned and operated by Dartmouth College. | Canberra Intrinsic High Purity Germanium Well Detectors |
| Aerosol and seawater beryllium-7 concentrations from the US GEOTRACES GP17-OCE cruise on R/V Roger Revelle (RR2214) in the South Pacific and Southern Oceans from December 2022 to January 2023 | FIU's facilities include four HPGe detectors: three Ortec Coaxial GEM series detectors and one Canberra Broad Energy gamma detector. The detectors were calibrated for the each geometry by adding a commercially prepared mixed isotope solution of known gamma activities (Eckert & Ziegler Mixed Nuclide Solution 7500) to three W-41 filters (for aerosol samples) and pellets of various thicknesses (for seawater) to derive a calibration curve using peaks associated with following isotopes: Sn-113 @ 392 keV, Sr-85 @ 514 keV, Cs-137 @ 662 keV. The counting efficiencies of the four detectors ranges from 0.05686 to 0.11415 for Be-7 on aerosol filters. And for the seawater pellets from this cruise, the counting efficiencies ranged from 0.03480 to 0.08590. | low background germanium gamma detectors |
| Aerosol and seawater beryllium-7 concentrations from the French GEOTRACES GS02 SWINGS cruise aboard R/V Marion-Dufresne (MD229) from January to March 2021 | FIU's facilities include four HPGe detectors: three Ortec Coaxial GEM series detectors and one Canberra Broad Energy gamma detector. The detectors were calibrated for the each geometry by adding a commercially prepared mixed isotope solution of known gamma activities (Eckert & Ziegler Mixed Nuclide Solution 7500) to three W-41 filters (for aerosol samples) and pellets of various thicknesses (for seawater) to derive a calibration curve using peaks associated with following isotopes: Sn-113 @ 392 keV, Sr-85 @ 514 keV, Cs-137 @ 662 keV. The counting efficiencies of the four detectors ranges from 0.05686 to 0.11415 for Be-7 on aerosol filters. And for the seawater pellets from this cruise, the counting efficiencies ranged from 0.03480 to 0.08590. | low background germanium gamma detectors |