@article {551, title = {A gas-accepting ion source for Accelerator Mass Spectrometry: Progress and applications}, journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms}, volume = {294}, year = {2013}, note = {id: 2161}, month = {Jan}, pages = {296-299}, abstract = {The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at the Woods Hole Oceanographic Institution has developed an Accelerator Mass Spectrometry (AMS) system designed specifically for the analysis of 14C in a continuously flowing stream of carrier gas. A key part of the system is a gas-accepting microwave ion source. Recently, substantial progress has been made in the development of this source, having achieved ion currents rivaling that of a traditional graphite source (albeit at relatively low efficiency). Details and present performance of the gas source are given. Additionally, representative results obtained from coupling the source to both a gas chromatograph and gas bench are presented.}, issn = {0168-583X}, doi = {10.1016/j.nimb.2011.10.016}, author = {Roberts, M. L. and von Reden, K. F. and Burton, J. R. and McIntyre, C. P. and Beaupre, S. R.} } @article {2463, title = {Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry}, journal = {Review of Scientific Instruments}, volume = {835240}, year = {2012}, month = {Jan-02-2012}, pages = {02B304}, abstract = {A 2.45 GHz microwave ion source coupled with a magnesium charge exchange canal (C {\texttimes} C) has been successfully adapted to a large acceptance radiocarbon accelerator mass spectrometry system at the National Ocean Sciences Accelerator Mass Spectrometry (AMS) Facility, Woods Hole Oceanographic Institution. CO2 samples from various preparation sources are injected into the source through a glass capillary at 370 μl/min. Routine system parameters are about 120{\textendash}140 μA of negative 12C current after the C {\texttimes} C, leading to about 400 14C counts per second for a modern sample and implying a system efficiency of 0.2\%. While these parameters already allow us to perform high-quality AMS analyses on large samples, we are working on ways to improve the output of the ion source regarding emittance and efficiency. Modeling calculations suggest modifications in the extraction triode geometry, shape, and size of the plasma chamber could improve emittance and, hence, ion transport efficiency. Results of experimental tests of these modifications are presented.}, issn = {0034-6748}, doi = {10.1063/1.3656408}, url = {http://aip.scitation.org/doi/10.1063/1.3656408http://aip.scitation.org/doi/pdf/10.1063/1.3656408}, author = {von Reden, K. F. and Roberts, M. L. and Burton, J. R. and {\'e}, S. R.} } @article {1829, title = {Age and Growth Rate Dynamics of an Old African Baobab Determined by Radiocarbon Dating}, journal = {Radiocarbon}, volume = {52}, year = {2010}, note = {Sp. Iss. 1696jn Times Cited:2 Cited References Count:21 }, month = {2010}, pages = {727-734}, abstract = {In 2008, a large African baobab (Adansonia digitata L.) from Makulu Makete, South Africa, split vertically into 2 sections, revealing a large enclosed cavity. Several wood samples collected from the cavity were processed and radiocarbon dated by accelerator mass spectrometry (AMS) for determining the age and growth rate dynamics of the tree. The C-14 date of the oldest sample was found to be of 1016 +/- 22 BP, which corresponds to a calibrated age of 1000 +/- 15 yr. Thus, the Makulu Makete tree, which eventually collapsed to the ground and died, becomes the second oldest African baobab dated accurately to at least 1000 yr. The conventional growth rate of the trunk, estimated by the radial increase, declined gradually over its life cycle. However, the growth rate expressed more adequately by the cross-sectional area increase and by the volume increase accelerated up to the age of 650 yr and remained almost constant over the past 450 yr.}, keywords = {cal kyr bp, Calibration, southern-hemisphere}, isbn = {0033-8222}, author = {Patrut, A. and Mayne, D. H. and von Reden, K. F. and Lowy, D. A. and Venter, S. and McNichol, A. P. and Roberts, M. L. and Margineanu, D.} } @article {1831, title = {A Continuous-Flow Gas Chromatography C-14 Accelerator Mass Spectrometry System}, journal = {Radiocarbon}, volume = {52}, year = {2010}, note = {Sp. Iss. 1696jn Times Cited:4 Cited References Count:24 }, month = {2010}, pages = {295-300}, abstract = {Gas-accepting ion sources for radiocarbon accelerator mass spectrometry (AMS) have permitted the direct analysis of CO2 gas, eliminating the need to graphitize samples. As a result, a variety of analytical instruments can be interfaced to an AMS system, processing time is decreased, and smaller samples can be analyzed (albeit with lower precision). We have coupled a gas chromatograph to a compact C-14 AMS system fitted with a microwave ion source for real-time compound-specific C-14 analysis. As an initial test of the system, we have analyzed a sample of fatty acid methyl esters and biodiesel. Peak shape and memory was better then existing systems fitted with a hybrid ion source while precision was comparable. C-14/C-12 ratios of individual components at natural abundance levels were consistent with those determined by conventional methods. Continuing refinements to the ion source are expected to improve the performance and scope of the instrument.}, keywords = {ams system, gc-ams, negative-ion source, RADIOCARBON ANALYSIS}, isbn = {0033-8222}, author = {McIntyre, C. P. and Galutschek, E. and Roberts, M. L. and von Reden, K. F. and McNichol, A. P. and Jenkins, W. J.} } @article {1830, title = {Fire History of a Giant African Baobab Evinced by Radiocarbon Dating}, journal = {Radiocarbon}, volume = {52}, year = {2010}, note = {Sp. Iss. 1696jn Times Cited:11 Cited References Count:28 }, month = {2010}, pages = {717-726}, abstract = {The article reports the first radiocarbon dating of a live African baobab (Adansonia digitata L.), by investigating wood samples collected from 2 inner cavities of the very large 2-stemmed Platland tree of South Africa. Some 16 segments extracted from determined positions of the samples, which correspond to a depth of up to 15-20 cm in the wood, were processed and analyzed by accelerator mass spectrometry (AMS). Calibrated ages of segments are not correlated with their positions in the stems of the tree. Dating results indicate that the segments originate from new growth layers, with a thickness of several centimeters, which cover the original old wood. Four new growth layers were dated before the reference year AD 1950 and 2 layers were dated post-AD 1950, in the post-bomb period. Formation of these layers was triggered by major damage inside the cavities. Fire episodes are the only possible explanation for such successive major wounds over large areas or over the entire area of the inner cavities of the Platland tree, able to trigger regrowth.}, keywords = {age calibration, bomb c-14 data, bombacaceae, cal kyr bp, southern-hemisphere, system}, isbn = {0033-8222}, author = {Patrut, A. and Mayne, D. H. and von Reden, K. F. and Lowy, D. A. and van Pelt, R. and McNichol, A. P. and Roberts, M. L. and Margineanu, D.} } @article {246, title = {A High-Performance (14)c Accelerator Mass Spectrometry System}, journal = {Radiocarbon}, volume = {52}, year = {2010}, note = {id: 2095; PT: J; CT: 20th International Radiocarbon Conference; CY: MAY 31-JUN 05, 2009; CL: Big Isl, HI; SI: 1; UT: WOS:000285437800005}, pages = {228-235}, abstract = {A new and unique radiocarbon accelerator mass spectrometry (AMS) facility has been constructed at the Woods Hole Oceanographic Institution. The defining characteristic of the new system is its large-gap optical elements that provide a larger-than-standard beam acceptance. Such a system is ideally suited for high-throughput, high-precision measurements of (14)C. Details and performance of the new system are presented.}, issn = {0033-8222}, doi = {10.2458/azu_js_rc.52.3657}, author = {Roberts, M. L. and Burton, J. R. and Elder, K. L. and Longworth, B. E. and McIntyre, C. P. and von Reden, K. F. and Han, B. X. and Rosenheim, B. E. and W. J. Jenkins and Galutschek, E. and McNichol, A. P.} } @article {1847, title = {Developments in Radiocarbon Technologies: From the Libby Counter to Compound-Specific Ams Analyses}, journal = {Radiocarbon}, volume = {51}, year = {2009}, note = {453wfTimes Cited:15 Cited References Count:273 }, month = {2009}, pages = {45-78}, abstract = {We review developments in radiocarbon measuring techniques from the Libby counter through proportional gas counters and liquid scintillation spectrometers to the more recent developments of accelerator mass spectrometry (AMS), followed by a coupling of gas chromatography with AMS for compound-specific (14)C analyses. While during the first 60 yr of (14)C measurements beta counting, specifically gas counting, was the dominant technique, in the future of (14)C science AMS will be the dominant technology.}, keywords = {accelerator mass-spectrometry, black-sea shelf, liquid scintillation techniques, low-level c-14, natural-abundance radiocarbon, negative-ion source, polycyclic aromatic-hydrocarbons, proportional counter, salt-marsh sediments, sedimentary organic-carbon}, isbn = {0033-8222}, author = {Povinec, P. P. and Litherland, A. E. and von Reden, K. F.} } @article {460, title = {Software development for continuous-gas-flow AMS}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {266}, year = {2008}, note = {id: 2091; PT: J; CT: 9th European Conference on Accelerators in Applied Research and Technology; CY: SEP 03-07, 2007; CL: Florence, ITALY; SP: Univ Florence, Dept Phys, Ist Nazl Fis Nucl; UT: WOS:000257185600033}, pages = {2233-2237}, abstract = {The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility at Woods Hole Oceanographic institution is presently completing installation of a novel continuous-flow AMS system. A multi-year development of an AMS microwave gas ion source in collaboration with Atomic Energy Canada Limited (AECL), Chalk River, has preceded this final step of an implementation that is expected to add a new dimension to (14)C AMS. National Instruments, NIM, and CAMAC modules have been programmed with Lab-VIEW on a Windows XP platform to form the basis for data acquisition. In this paper we discuss possible applications and include simulations of expected data acquisition scenarios like real-time AMS analysis of chromatograms. Particular attention will have to be given to issues of synchronization between rapidly changing input amplitudes and signal processing cycles in hardware and software. (C) 2008 Elsevier B.V. All rights reserved.}, issn = {0168-583X}, doi = {10.1016/j.nimb.2008.03.001}, author = {von Reden, K. F. and Roberts, M. L. and W. J. Jenkins and Rosenheim, B. E. and McNichol, A. P. and Schneider, R. J.} } @article {565, title = {Computer simulation of MC-SNICS for performance improvements}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {261}, year = {2007}, note = {200swTimes Cited:8Cited References Count:8}, month = {Aug}, pages = {588-593}, abstract = {Increasing ion source current output while keeping the beam emittance small is a key for improving measurement throughput and quality of an accelerator mass spectrometry (AMS) system. The NEC MC-SNICS ion sources have widely been used for AMS around the world. In this work, a computer simulation study on MC-SNICS ion source was carried out using the code PBGUNS. The primary Cs+ beam is simulated as space-charge limited emission from the ionizer surface. The secondary negative ion beam is simulated in the presence of the space-charge induced by both the primary and the secondary beam. Two different configurations of the MC-SNICS have been studied: the original factory version and the UC Irvine modified version. The latter has a 0.668 in. radius spherical ionizer and an immersion lens at cathode potential with the original Cs focus lens removed. Simulation showed that the modified version provides more intense and better focused Cs+ beam at the cathode target, hence higher negative ion production from the sample by sputtering. The new arrangement of Einzel-preacceleration section of the MC-SNICS at UC Irvine was also simulated and discussed. Simulation results are in good agreement with the experimental observations made at UC Irvine. Hints for selection of an immersion lens geometry have been obtained. (c) 2007 Elsevier B.V. All rights reserved.}, issn = {0168-583x}, doi = {10.1016/j.nimb.2007.03.060}, author = {Han, B. X. and Southon, J. R. and Roberts, M. L. and von Reden, K. F.} } @article {462, title = {Electromagnetic field modeling and ion optics calculations for a continuous-flow AMS system}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {259}, year = {2007}, note = {id: 1698; 182WV Times Cited:6 Cited References Count:14}, pages = {111-117}, abstract = {A continuous-flow C-14 AMS (CFAMS) system is under construction at the NOSAMS facility. This system is based on a NEC Model 1.5SDH-10.5 MV Pelletron accelerator and will utilize a combination of a microwave ion source (MIS) and a charge exchange canal (CXC) to produce negative carbon ions from a continuously flowing stream Of CO2 gas. For high-efficiency transmission of the large emittance, large energy-spread beam from the ion source unit, a large-acceptance and energy-achromatic injector consisting of a 45 degrees electrostatic spherical analyzer (ESA) and a 90 degrees double-focusing magnet has been designed. The 45 degrees ESA is rotatable to accommodate a 134-sample MC-SNICS as a second ion source. The high-energy achromat (90 degrees double focusing magnet and 90 degrees ESA) has also been customized for large acceptance. Electromagnetic field modeling and ion optics calculations of the beamline were done with Infolytica MagNet, ElecNet, and Trajectory Evaluator. PBGUNS and SIMION were used for the modeling of ion source unit. (c) 2007 Elsevier B.V. All rights reserved.}, issn = {0168-583X}, doi = {10.1016/J.Nimb.2007.01.224}, author = {Han, B. X. and von Reden, K. F. and Roberts, M. L. and Schneider, R. J. and Hayes, J. M. and W. J. Jenkins} } @article {567, title = {Progress on a gas-accepting ion source for continuous-flow accelerator mass spectrometry}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {259}, year = {2007}, note = {182wvTimes Cited:24Cited References Count:12}, month = {Jun}, pages = {83-87}, abstract = {A gas-accepting microwave-plasma ion source is being developed for continuous-flow accelerator mass spectrometry (AMS). Characteristics of the ion source will be presented. Schemes for connecting a gas or liquid chromatograph to the ion source will also be discussed. (c) 2007 Ellsevier B.V. All rights reserved.}, issn = {0168-583x}, doi = {10.1016/j.nimb.2007.01.189}, author = {Roberts, M. L. and Schneider, R. J. and von Reden, K. F. and Wills, J. S. C. and Han, B. X. and Hayes, J. M. and Rosenheim, B. E. and W. J. Jenkins} } @article {1896, title = {Radiocarbon dating of a very large African baobab}, journal = {Tree Physiology}, volume = {27}, year = {2007}, note = {230afTimes Cited:35 Cited References Count:43 }, month = {Nov}, pages = {1569-1574}, abstract = {In late 2004, Grootboom, probably the largest known African baobab (Adansonia digitata L.), collapsed unexpectedly in northeastern Namibia. Ten wood samples collected from different areas of the trunk were processed and investigated by accelerator mass spectrometry radiocarbon dating. The radiocarbon dates of three samples were greater than 1000 years BP (radiocarbon years before present, i.e., before AD 1950). The corresponding calibrated calendar age of the oldest sample was 1275 +/- 50 years, making Grootboom the oldest known angiosperm tree with reliable dating results. Variations in radiocarbon dates among the wood samples indicated that, morphologically, Grootboom was a quintuple tree, whereas genetically, it was a single individual. Ages of extreme lateral samples revealed that, over the past 500-600 years, Grootbooom had almost ceased growing, providing information about climate changes in central southern Africa. The sudden demise of Grootboom coincided with the spread of the poorly studied baobab disease, which has become epidemic in Namibia.}, keywords = {Adansonia digitata, Age, Age determination, amazonia, c-14 content, cal kyr bp, Calibration, dendrochronology, dendroclimatology, holocene logs, location-dependent differences, southern-hemisphere, tasmanian conifers, Trees, tropical trees}, isbn = {0829-318x}, author = {Patrut, A. and von Reden, K. F. and Pohlman, J. W. and Wittmann, R. and Mitchell, C. S. and Lowy, D. A. and Alberts, A. H. and Gerlach, D. and Xu, L.} } @conference {1542, title = {A 2.45 GHz Ion Source for use in Accelerator Mass Spectrometry}, booktitle = {11th International Conference on Ion Ssources}, year = {2005}, note = {id: 1707}, month = {2005}, address = {Caen, France}, author = {von Reden, K. F. and Schneider, R. J. and Roberts, M. L. and Han, B. X. and Wills, J.} } @conference {1543, title = {3-D Electromagnetic Field Modeling and Ion Optics Calculations for a Continuous-Flow AMS System}, booktitle = {10th International Conference on Accelerator Mass Spectrometry}, year = {2005}, note = {id: 1708}, month = {2005}, address = {Berkeley, California}, author = {Han, B. X. and von Reden, K. F. and Roberts, M. L. and Schneider, R. J. and Hayes, J. M.} } @conference {1576, title = {Beam Profile Measurements for a MC-SNICS Source with Spherical Ionizer}, booktitle = {10th International Conference on Accelerator Mass Spectrometry}, year = {2005}, note = {id: 1706}, month = {2005}, address = {Berkeley, California}, author = {von Reden, K. F. and Griffin, V. S. and Roberts, M. L.} } @conference {1598, title = {Continuous-Flow Accelerator Mass Spectrometry}, booktitle = {the International Symposium on Utilization of Accelerators}, series = {IAEA-CN-115-09}, year = {2005}, note = {id: 767}, month = {2005}, address = {Dubrovnik Croatia}, author = {Roberts, M. L. and von Reden, K. F. and Han, B. X. and Schneider, R. J. and Benthien, A. and Hayes, J. M.} } @conference {1759, title = {Progress on a Gas Ion Source for Continuous-Flow Accelerator Mass Spectrometry}, booktitle = {10th International Conference on Accelerator Mass Spectrometry}, year = {2005}, note = {id: 768}, month = {2005}, address = {Berkeley, California}, author = {Roberts, M. L. and Schneider, R. J. and von Reden, K. F. and Han, B. X. and Rosenheim, B. E. and Hayes, J. M.}, editor = {Knezovich, J. and et al.} } @article {464, title = {A gas ion source for continuous-flow AMS}, journal = {Proceedings of the Ninth International Conference on Accelerator Mass Spectrometry}, volume = {223-224}, year = {2004}, note = {id: 2104}, pages = {149-154}, abstract = {The first gas-fed ion source for radiocarbon AMS applications (without sputtering) has been operated at the Woods Hole NOSAMS Facility. A three-year, off-line test program resulted in positive carbon ion currents up to 1 mA and negative ion currents up to 80 μA. Recently, the compact, permanent-magnet microwave plasma ion source and magnesium vapor charge-exchange canal were coupled to the recombinator injector of the 2.5 MV Tandetron. When the ion source was operated on CO2 at a flow rate of about 200 μl per minute, negative carbon ion beams up to 20 μA were obtained, at an energy of 35 keV. Radiocarbon measurements were performed on standard reference gases and the dynamic response to square-wave pulses of gas was determined. Time constants in the ion source are less than 1 s, which should allow analysis of chromatographic peaks of CO2 with very little broadening. A combustion device has been constructed to generate CO2 for direct injection into the source. Argon carrier gas is used to buffer the pressure at one atmosphere in the sample gas injector. A dedicated ion-beam injector, with higher angular acceptance and higher transmitted currents, is being constructed for the AMS system.}, issn = {0168-583X}, doi = {10.1016/j.nimb.2004.04.031}, author = {Schneider, R. J. and Kim, S. W. and von Reden, K. F. and Hayes, J. M. and Wills, J. S. C. and Griffin, V. S. and Sessions, A. L. and Sylva, S.} } @conference {1597, title = {Continuous-Flow Accelerator Mass Spectrometry}, booktitle = {International Symposium on Radiation Physics}, year = {2003}, note = {id: 1683}, month = {2003}, address = {Mexico City, Mexico}, author = {Roberts, M. L. and Benthien, A. and Schneider, R. J. and von Reden, K. F. and Hayes, J. M.} } @conference {1744, title = {Plans for expanded 14C analyses at the NOSAMS facility - a status and progress report}, booktitle = {International Conference on Accelerator Mass Spectrometry}, year = {2002}, note = {id: 1685}, month = {2002}, address = {Nagoya, Japan}, author = {von Reden, K. F. and Donoghue, J. and Elder, K. and Gagnon, A. and Gerlach, D. and Griffin, V. and Healy, R. and Long, P. and McNichol, A. and Percy, D. and Roberts, M. L. and Schneider, R. J. and Xu, L. and Hayes, J. M.} } @article {713, title = {Test of negative ion beams from a microwave ion source with a charge exchange canal for accelerator mass spectrometry applications}, journal = {Review of Scientific Instruments}, volume = {73}, year = {2002}, note = {2522wyTimes Cited:8Cited References Count:7}, month = {Feb}, pages = {846-848}, abstract = {A test facility has been constructed to evaluate negative ion beams from small gaseous samples for accelerator mass spectrometry applications. The positive ion beams from the microwave ion source are passed into a charge-exchange canal (CXC) where the ions exchange electrons with magnesium vapor and become negatively charged. Positive molecular ions were: either neutralized or broken up into atomic ions and neutral atoms and molecules by collision processes. Most of the resulting particles were suspected to be neutrals. In studies with injections of CO2 pulses, the resulting positive and negative C-12 current peaks gave a 0.09\% yield of C- ions from CO2 molecules, which includes a charge-exchange efficiency of 10\%. Since nitrogen does not form a stable negative ion, N-14 background is virtually eliminated after the beam goes through the CXC, which is necessary for radiocarbon measurements. (C) 2002 American Institute of Physics.}, issn = {0034-6748}, doi = {10.1063/1.1430517}, author = {Kim, S. W. and Schneider, R. J. and von Reden, K. F. and Hayes, J. M. and Wills, J. S. C.} } @article {966, title = {WOCE radiocarbon IV: Pacific Ocean results; P10, P13N, P14C, P18, P19 \& S4P}, journal = {Radiocarbon}, volume = {44}, year = {2002}, note = {591keTimes Cited:33Cited References Count:56}, pages = {239-392}, abstract = {The World Ocean Circulation Experiment, carried out between 1990 and 1997, provided the most comprehensive oceanic survey of radiocarbon to date. Approximately 10,000 samples were collected in the Pacific Ocean by U.S. investigators for both conventional large volume P counting and small volume accelerator mass spectrometry analysis techniques. Results from six cruises are presented. The data quality is as good or better than previous large-scale surveys. The C-14 distribution for the entire WOCE Pacific data set is graphically described using mean vertical profiles and sections, and property-property plots.}, issn = {0033-8222}, url = {https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/4097}, author = {Key, R. M. and Quay, P. D. and Schlosser, P. and McNichol, A. P. and von Reden, K. F. and Schneider, R. J. and Elder, K. L. and Stuiver, M. and Ostlund, H. G.} } @conference {1787, title = {A Silent Tandetron AMS System}, booktitle = {Proceedings of the 31st SNEAP}, year = {2001}, note = {id: 1680}, month = {2001}, publisher = {World Scientific Publishing Co.}, organization = {World Scientific Publishing Co.}, address = {Julich, Germany}, author = {von Reden, K. F. and Schneider, R. J.} } @article {2436, title = {Installation of a 134-sample MC-SNICS ion source at NOSAMS and first results}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {172}, year = {2000}, note = {8th International Conference on Accelerator Mass SpectrometrySEP 06-10, 1999 VIENNA, AUSTRIA }, month = {Oct}, pages = {247-251}, abstract = {In April 1999, the National Ocean Sciences AMS (NOSAMS) facility received the shipment of a 134-sample MC-SNICS ion source from the National Electrostatics Corporation (NEC). It replaced one of the two 59-sample spherical ionizer sources (US-AMS Model 3090A, HVEE Model 846). In this paper, we will describe the adaptation of the NEC ion source to the US-AMS/HVEE recombinator injector at NOSAMS. This is the first lime that the two leading sputter ion source designs are directly comparable on the same system. We will present ion beam optics calculations for both in comparison with measured results. Once fully operational, the new ion source will assume all of the sputter sample measurements at NOSAMS, while the remaining 59-sample source will be replaced by the newly developed microwave gas ion source. One of the most desirable features of the MC-SNICS design is the smaller cathode geometry. At comparable extracted currents, the surface diameter of the pressed samples is reduced from 1.5 to 1 mm. A new, automatic sample pressing procedure is being developed for this design. This will improve the capability for preparing and analyzing smaller sputter samples (carbon weight <100 g). Our US-AMS cathodes showed considerable reduction in the extracted currents when the sample diameter was reduced to 1 mm, even with samples of normal size (>200 mug C). (C) 2000 Elsevier Science B.V. All rights reserved.}, keywords = {AMS, beam extraction/injection, C-14, ion sources, ocean, pacific}, isbn = {0168-583X}, author = {von Reden, K. F. and Bellino, M. and Long, P. and Schneider, R. J. and Loger, R.} } @conference {1767, title = {The radiocarbon gradient at the Antarctic Polar Front}, booktitle = {AGU Ocean Sciences Meeting}, year = {2000}, note = {id: 317}, month = {2000}, address = {San Antonio, TX}, author = {Schneider, R. J. and McNichol, A. P. and von Reden, K. F. and Elder, K. L. and Gagnon, A. R. and Key, R. M. and Quay, P. D. and Schlosser, P. M.} } @conference {1804, title = {Ten years after - the WOCE AMS radiocarbon program}, booktitle = {Accelerator Mass Spectrometer Conference}, year = {2000}, note = {id: 316}, month = {2000}, author = {McNichol, A. P. and Schneider, R. J. and von Reden, K. F. and Gagnon, A. R. and Elder, K. L. and Key, R. M. and Quay, P. D.} } @article {810, title = {Ten years after - The WOCE AMS radiocarbon program}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {172}, year = {2000}, note = {372jrTimes Cited:14Cited References Count:12}, month = {Oct}, pages = {479-484}, abstract = {The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility is measuring all of the samples collected as part of the US WOCE Program - over 13,000 samples. We designed our extraction lines so that we also measure precise, oceanographically useful delta C-13-Sigma CO2 values. We have completed the analysis of samples from the Pacific and Southern Oceans and are processing those from the Indian Ocean now. At present, this constitutes the world{\textquoteright}s largest AMS data set. Reviews of the Pacific radiocarbon data are available and demonstrate the increased penetration of the "bomb signal" into the water column since the 1970s. Stable isotope data are being combined with those collected as part of NOAA{\textquoteright}s Ocean-Atmosphere Carbon Exchange Study to study the ocean{\textquoteright}s role in the anthropogenic CO2 cycle. The relationship of delta C-13 to other chemical tracers, e.g., PO4, O-2 and chlorofluorocarbons, will further our understanding of basic oceanographic processes. We present preliminary results from these studies as well as investigate the relationship of C-14 to C-13 in the ocean. (C) 2000 Elsevier Science B.V. All rights reserved.}, issn = {0168-583x}, doi = {10.1016/S0168-583x(00)00093-8}, author = {McNichol, A. P. and Schneider, R. J. and von Reden, K. F. and Gagnon, A. R. and Elder, K. L. and Key, R. M. and Quay, P. D.} } @article {809, title = {Tests of positive ion beams from a microwave ion source for AMS}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {172}, year = {2000}, note = {372jrTimes Cited:16Cited References Count:4}, month = {Oct}, pages = {252-256}, abstract = {A test facility has been constructed to evaluate high-current positive ion beams from small gaseous samples for AMS applications. The major components include a compact permanent magnet microwave ion source built at the AECL Chalk River Laboratory and now on loan from the University of Toronto, and a double-focusing spectrometer magnet on loan from Argonne National Laboratory. Samples are introduced by means of a silica capillary injection system. Loop injection into a carrier gas provides a stable feed for the microwave driven plasma. The magnetic analysis system is utilized to isolate carbon ions derived from CO? samples from other products of the plasma discharge, including argon ions of the carrier gas. With a smaller discharge chamber, we hope to exceed a conversion efficiency of 14\% for carbon ions produced per atom, which we reported at AMS-7. The next step will be to construct an efficient charge-exchange cell, to produce negative ions for injection into the WHOI recombinator injector. (C) 2000 Elsevier Science B.V. All rights reserved.}, issn = {0168-583x}, doi = {10.1016/S0168-583x(00)00131-2}, author = {Schneider, R. J. and von Reden, K. F. and Hayes, J. M. and Wills, J. S. C. and Kern, W. G. E. and Kim, S. W.} } @conference {1567, title = {Application of a compact microwave ion source to radiocarbon analysis}, booktitle = {The eighth international conference on heavy-ion accelerator technology}, year = {1999}, note = {id: 1977}, month = {1999}, pages = {422}, publisher = {American Institute of Physics}, organization = {American Institute of Physics}, abstract = {The compact, high current, 2.45 GHz microwave-driven plasma ion source which was built for the Chalk River TASCC facility is presently being adapted for testing as a gas ion source for accelerator mass spectrometry, at the Woods Hole Oceanographic Institution accelerator mass spectrometer. The special requirements for producing carbon-ion beams from micromole quantities of carbon dioxide produced from environmental samples will be discussed. These samples will be introduced into the ion source by means of argon carrier gas and a silicon capillary injection system. Following the extraction of positive ions from the source, negative ion formation in a charge exchange vapor will effectively remove the argon from the carbon beam. Simultaneous injection of the three carbon isotopes into the accelerator is planned.}, keywords = {carbon, ion sources, mass spectroscopy, spectrochemical analysis, tandem accelerators}, author = {Schneider, R. J. and von Reden, K. F. and Hayes, J. M. and Wills, J. S. C.}, editor = {Shepard, K. W.} } @conference {1569, title = {Application of Compact Microwave Ion Source to Radiocarbon Analysis}, booktitle = {8th International Conference on Heavy Ion Accelerator Technology}, volume = {Conference Proceedings 473}, year = {1999}, note = {id: 1824}, month = {1999}, pages = {422-425}, publisher = {American Institute of Physics}, organization = {American Institute of Physics}, address = {Argonne National Lab.}, author = {Schneider, R. J. and von Reden, K. F. and Hayes, J. M. and Wills, J. S. C.}, editor = {Shepard, K.} } @conference {1653, title = {Installation and First Results of a 134-Sample MC-SNICS Ion Source at NOSAMS}, booktitle = {8th International Conference on Accelerator Mass Spectrometry}, year = {1999}, note = {id: 1802}, month = {1999}, address = {Vienna, Austria}, author = {von Reden, K. F. and Schneider, R. J. and McNichol, A. P. and Elder, K. F. and Gagnon, A. R.} } @inbook {1473, title = {New Developments at the NOSAMS Facility}, booktitle = {Proceeding of the International Workshop on Frontiers in Accelerator Mass Spectrometry}, year = {1999}, note = {id: 1723(JISTEC) }, month = {1999}, pages = {44-52}, publisher = {National Institute for Environmental Studies, Tsukuba, National Museum of Japanese History}, organization = {National Institute for Environmental Studies, Tsukuba, National Museum of Japanese History}, address = {Tsukuba, Japan}, author = {von Reden, K. F. and Schneider, R. J. and McNichol, A. P. and Hayes, J. M. and Pearson, A. and Eglinton, T. I.}, editor = {Science, Japan International and Technology Exchange, Center} } @conference {1705, title = {New Developments at the NOSAMS Facility}, booktitle = {International Workshop on Frontiers in Accelerator Mass Spectrometry}, year = {1999}, note = {id: 1679}, month = {1999}, publisher = {National Institute for Environmental Studies Reprot}, organization = {National Institute for Environmental Studies Reprot}, address = {Tsukuba, Japan}, author = {von Reden, K. F. and Schneider, R. J. and McNichol, A. P. and Hayes, J. M. and Pearson, A. and Eglinton, T. I.}, editor = {Shibata, Y.} } @conference {1559, title = {AMS measurement of}, booktitle = {Sixteenth International Radiocarbon Conference}, volume = {40(1)}, year = {1998}, note = {id: 1643}, month = {1998}, pages = {247-253}, address = {Groningen}, author = {von Reden, K. F. and McNichol, A. P. and Pearson, A. and Schneider, R. J.} } @article {2249, title = {AMS Measurement of small samples with high-current system: (Proceedings of the 16th International Radiocarbon Conference, 1997)}, journal = {Radiocarbon}, volume = {40}, year = {1998}, note = {id: 1815}, month = {1998}, pages = {247-253}, author = {von Reden, K. F. and McNichol, A. and Pearson, A. and Schneider, R.} } @inbook {1461, title = {A Correction for Aberrations in the Woods Hole Recombinator}, booktitle = {Symposium of North-Eastern Accelerator Personnel, SNEAP 1996}, year = {1998}, note = {id: 1823}, month = {1998}, pages = {123-128}, publisher = {World Scientific}, organization = {World Scientific}, address = {Woods Hole, MA}, author = {Schneider, R. J. and von Reden, K. F.}, editor = {von Reden, Karl F.} } @article {2256, title = {A Correction for Aberrations in the Woods Hole Recombinator. Symposium of North-Eastern Accelerator Personnel}, journal = {World Scientific}, volume = {SNEAP 1996}, year = {1998}, note = {id: 1793}, month = {1998}, pages = {123-128}, author = {Schneider, R. J. and von Reden, K. F.} } @conference {1646, title = {High-precision Measurements of 14C as a Circulation Tracer in the Pacific, Indian, and Southern Oceans with Accelerator Mass Spectrometry (AMS)}, booktitle = {8th International Conference on Heavy Ion Accelerator Technology}, year = {1998}, note = {id: 1636}, month = {1998}, address = {Argonne National Lab}, author = {von Reden, K. F. and Peden, J. C. and Schneider, R. J. and Bellino, M. and Donoghue, J. and Elder, K. L. and Gagnon, A. R. and Long, P. and McNichol, A. P. and Morin, T. and Stuart, D. and Hayes, J. M. and Key, R. M.}, editor = {Shepard, K. American Institute of Physics} } @article {1512, title = {Method and Technology of AMS}, year = {1998}, note = {id: 1677}, month = {1998}, institution = {University of Mass., Dartmouth}, address = {Dartmouth, MA}, author = {von Reden, K. F.} } @article {2262, title = {Microscale AMS 14C measurements at NOSAMS}, journal = {Radiocarbon}, volume = {40}, year = {1998}, note = {id: 1621}, month = {1998}, pages = {61-75}, author = {Pearson, A. and McNichol, A. P. and Schneider, R. J. and von Reden, K. F. and Zheng, Y.} } @article {2261, title = {Microscale AMS 14C measurements at NOSAMS: (Proceedings of the 16th International Radiocarbon Conference, 1997)}, journal = {Radiocarbon}, volume = {40}, year = {1998}, note = {id: 1814}, month = {1998}, pages = {61-75}, author = {Pearson, A. and McNichol, A. P. and Schneider, R. J. and von Reden, K. F. and Zheng, Y.} } @conference {1713, title = {NOSAMS Controls with LabView}, booktitle = {Proceedings of the 30th Symposium of Northeastern Accelerator Personnel - Woods Hole, 1996}, year = {1998}, note = {id: 1764}, month = {1998}, publisher = {World Scientific Publishing Co., Singapore}, organization = {World Scientific Publishing Co., Singapore}, author = {von Reden, K. F.}, editor = {von Reden, K. F.} } @article {2250, title = {NOSAMS Controls with LabView}, journal = {World Scientific}, year = {1998}, note = {id: 1675}, month = {1998}, author = {von Reden, K. F.} } @inbook {1470, title = {NOSAMS Controls with LabView}, booktitle = {Symposium of North-Eastern Accelerator Personnel, Woods Hole Oceanographic Institution, Woods Hole, USE, October 27-30, 1996, SNEAP XXX}, year = {1998}, note = {id: 1721}, month = {1998}, pages = {189-199}, publisher = {World Scientific Publishing Co.}, organization = {World Scientific Publishing Co.}, address = {Woods Hole, MA}, author = {von Reden, K. F.}, editor = {von Reden, K. F.} } @article {2259, title = {Preparation for continuous flow accelerator mass spectrometry Radiocarbon}, journal = {Radiocarbon}, volume = {1}, year = {1998}, note = {id: 1623}, month = {1998}, author = {Schneider, R. J. and Hayes, J. M. and von Reden, K. F. and McNichol, A. P. and Eglinton, T. and Wills, J. S. C.} } @article {2247, title = {Proceedings of the 30th Symposium of Northeastern Accelerator Personnel - Woods Hole, 1996}, journal = {World Scientific}, year = {1998}, note = {id: 1674}, month = {1998}, author = {von Reden, K. F. and Schneider, R. J.} } @conference {1753, title = {Proceedings of the 8th International Conference on Heavy Ion Accelerator Technology}, booktitle = {American Institute of Physics, Conference Proceeding Series}, year = {1998}, note = {id: 1624; submitted}, month = {1998}, address = {Argonne National Lab}, author = {Schneider, R. J. and von Reden, K. F. and Hayes, J. M. and Wills, J. S. C.} } @article {2276, title = {Status Report of the National Ocean Sciences AMS Facility at Woods Hole Oceanographic Institution: Operations and Recent Developments}, journal = {15th International Conference on the Applications of Accelerators in Research and Industry}, volume = {A.I.P. Conference Proceedings}, year = {1998}, note = {id: 1647}, month = {1998}, pages = {644-647}, author = {Bellino, M. and von Reden, K. F. and Schneider, R. J. and Peden, J. C. and Donoghue, J. and Elder, K. L. and Gagnon, A. R. and Long, P. and McNichol, A. P. and Odegaard, A. P. and Stuart, D. and Handwork, S. and Hayes, J. M.} } @article {2258, title = {Target preparation for continuous flow accelerator mass spectrometry}, journal = {Radiocarbon}, volume = {40}, year = {1998}, note = {1 Sp. Iss. SI113kt Times Cited:11 Cited References Count:10 }, month = {1998}, pages = {95-102}, abstract = {For very small samples, it is difficult to prepare graphitic targets that will yield a useful and steady sputtered ion beam. Working with materials separated by preparative capillary gas chromatography, we have succeeded with amounts as small as 20 mu g C. This seems to be a practical limit, as it involves 1) multiple chromatographic runs with trapping of effluent fractions, 2) recovery and combustion of the fractions, 3) graphitization and 4) compression of the resultant graphite/cobalt matrix into a good sputter target. Through such slow and intricate work, radiocarbon ages of lignin derivatives and hydrocarbons from coastal sediments have been determined. If this could be accomplished as an "online" measurement by flowing the analytes directly into a microwave gas ion source, with a carrier gas, then the number of processing steps could be minimized. Such a system would be useful not just for chromatographic effluents, but for any gaseous material, such as CO2 produced from carbonates. We describe tests using such an ion source.}, keywords = {gas, ion-source}, isbn = {0033-8222}, author = {Schneider, R. J. and Hayes, J. M. and von Reden, K. F. and McNichol, A. P. and Eglinton, T. I. and Wills, J. S. C.} } @conference {1560, title = {AMS measurements of the 14C distribution in the Pacific Ocean}, booktitle = {Proceedings of the Seventh International Conference on Accelerator Mass Spectrometry}, volume = {B123}, year = {1997}, note = {id: 1644; B123}, month = {1997}, pages = {438-442}, address = {Tucson, AZ}, author = {von Reden, K. F. and McNichol, A. P. and Peden, J. C. and Elder, K. L. and Gagnon, A. R. and Schneider, R. J.}, editor = {Jull, A. J. T.} } @article {2280, title = {AMS measurements of the 14C distribution in the Pacific Ocean}, journal = {Nuclear Instruments and Methods in Physics Research}, volume = {B123}, year = {1997}, note = {id: 1673}, month = {1997}, pages = {438-442}, author = {von Reden, K. F. and McNichol, A. P. and Peden, J. C. and Elder, K. L. and Gagnon, A. R. and Schneider, R. J.} } @conference {1607, title = {Determination of the radiocarbon ages of individual PAH extracted from urban aerosol and marine sediment}, booktitle = {16th International Radiocarbon Conference}, volume = {Book of Abstracts}, year = {1997}, note = {id: 951}, month = {1997}, pages = {148}, address = {Groningen}, author = {Pearson, A. and Eglinton, T. I. and McNichol, A. P. and Currie, L. A. and Schneider, R. J. and von Reden, K. F. and Benner, B. A. and Wise, S. A.} } @conference {1803, title = {Target preparation for continuous flow accelerator mass spectrometry}, booktitle = {16th International Radiocarbon Conference}, volume = {Book of Abstracts}, year = {1997}, note = {id: 953}, month = {1997}, pages = {165}, address = {Groningen}, author = {Schneider, R. J. and Hayes, J. M. and Eglinton, T. I. and McNichol, A. P. and von Reden, K. F.} } @article {2287, title = {Target preparation for continuous flow accelerator mass spectrometry}, journal = {Radiocarbon}, volume = {40}, year = {1997}, note = {id: 1661}, month = {1997}, pages = {95-102}, author = {Schneider, R. J. and Hayes, J. M. and von Reden, K. F. and McNichol, A. P. and Eglinton, T. I.} } @article {2288, title = {Target preparation for continuous flow accelerator mass spectrometry: (Proceedings of the 16th International Radiocarbon Conference, 1997)}, journal = {Radiocarbon}, volume = {40}, year = {1997}, note = {id: 1752}, month = {1997}, pages = {95-102}, author = {Schneider, R. J. and Hayes, J. M. and von Reden, K. F. and McNichol, A. P. and Eglinton, T.} } @conference {1561, title = {AMS measurements of the 14C distribution in the Pacific Ocean}, booktitle = {7th International Conference on Accelerator Mass Spectrometry}, volume = {38}, year = {1996}, note = {id: 950; 1}, month = {1996}, pages = {125}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {Tucson, AZ}, author = {von Reden, K. F. and McNichol, A. P. and Schneider, R. J.} } @conference {1635, title = {Expanded Small Sample Capabilities at NOSAMS: Preparation and Analysis of Conventional Graphite Targets Containing 0.15 mg Carbon}, booktitle = {7th International Conference on Accelerator Mass Spectrometry}, volume = {38}, year = {1996}, note = {id: 946; 1}, month = {1996}, pages = {97}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {Tucson, AZ}, author = {Pearson, A. and McNichol, A. P. and Schneider, R. J. and von Reden, K. F.} } @article {2337, title = {Isolation of Individual Organic Compounds for AMS Radiocarbon Analysis--A Novel Approach}, journal = {Radiocarbon}, volume = {38}, year = {1996}, note = {id: 1650}, month = {1996}, pages = {26}, author = {Eglinton, T. I. and McNichol, A. P. and Benitez-Nelson, B. C. and Pearson, A. and von Reden, K. F. and Schneider, R. J. and Bauer, J. E. and Druffel, E. R. M.} } @conference {1658, title = {Isolation of Individual Organic Compounds for AMS Radiocarbon Analysis -- A Novel Approach}, booktitle = {7th International Conference on Accelerator Mass Spectrometry}, volume = {38}, year = {1996}, note = {id: 1800; 1}, month = {1996}, pages = {26}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {Tucson, AZ}, author = {Eglinton, T. I. and McNichol, A. P. and Benitez-Nelson, B. C. and Pearson, A. and von Reden, K. F. and Schneider, R. J. and Bauer, J. E. and Druffel, E. R. M.} } @conference {1660, title = {Kinematic Effects in the Sputtering of Carbon Isotopes}, booktitle = {7th International Conference on Accelerator Mass Spectrometry}, volume = {38}, year = {1996}, note = {id: 1801; 1}, month = {1996}, pages = {108}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {Tucson, AZ}, author = {Schneider, R. J. and Hartman, J. and von Reden, K. F. and McNichol, A. P.} } @article {2311, title = {Kinematic Effects in the Sputtering of Carbon Isotopes}, journal = {Radiocarbon}, volume = {1}, year = {1996}, note = {id: 1660}, month = {1996}, pages = {108}, author = {Schneider, R. J. and Hartman, J. and von Reden, K. F. and McNichol, A. P.} } @article {2306, title = {Molecular breakup of CO2 and hold-up time in a microwave ion source}, year = {1996}, note = {id: 949}, month = {1996}, author = {Wills, J. S. C. and Diamond, W. T. and Lewis, R. A. and Schmeing, H. and von Reden, K. F. and Schneider, R. J.} } @article {2307, title = {Progress of the NOSAMS Facility WOCE 14C Data Analysis}, journal = {Radiocarbon}, volume = {38}, year = {1996}, note = {id: 1672}, month = {1996}, pages = {123}, author = {von Reden, K. F. and McNichol, A. P. and Schneider, R. J.} } @conference {1755, title = {Progress of the NOSAMS Facility WOCE 14C data analysis}, booktitle = {7th International Conference on Accelerator Mass Spectrometry}, volume = {38}, year = {1996}, note = {id: 948; 1}, month = {1996}, pages = {123}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {Tucson, AZ}, author = {von Reden, K. F. and McNichol, A. P. and Schneider, R. J.} } @conference {1756, title = {Progress of the NOSAMS Facility WOCE 14C Data Analysis}, booktitle = {Workshop on Applications of AMS to Global Climate Change}, volume = {38}, year = {1996}, note = {id: 1768; 1}, month = {1996}, pages = {123}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {La Jolla}, author = {von Reden, K. F. and McNichol, A. P. and Schneider, R. J.} } @conference {1757, title = {Progress of the NOSAMS Facility WOCE 14C Data Analysis, Workshop on Applications of AMS to Global Climate Change}, booktitle = {Workshop on Applications of AMS to Global Climate Change}, volume = {38}, year = {1996}, note = {id: 954; 8}, month = {1996}, pages = {123}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {La Jolla}, author = {von Reden, K. F. and McNichol, A. P. and Schneider, R. J.} } @conference {1758, title = {Progress of the NOSAMS facility WOCE (super 14) C data analysis}, volume = {38}, year = {1996}, note = {id: 2242; Source type: conferencepapers\&proceedings; Object type: Article; Object type: Conference Paper; Copyright: GeoRef, Copyright 2007, American Geological Institute.; CSAUnique: 1999-071631; AccNum: 1999-071631; ISSN: 0033-8222; CODEN: RACAAT}, month = {1996}, pages = {123}, publisher = {University of Arizona, Department of Geosciences, Tucson, AZ, United States (USA)}, organization = {University of Arizona, Department of Geosciences, Tucson, AZ, United States (USA)}, address = {United States (USA)}, keywords = {02D, 07, accelerator mass spectroscopy, C-14, carbon, Isotope geochemistry, isotopes, mass spectroscopy, Oceanography, Pacific Ocean, progress report, radioactive isotopes, report, sea water, spectroscopy}, author = {von Reden, K. F. and McNichol, A. P. and Schneider, Robert J.} } @conference {1794, title = {Stable and radio-carbon isotope measurements in the Pacific Ocean; contributions from NOSAMS}, volume = {77}, year = {1996}, note = {id: 2240; Source type: conferencepapers\&proceedings; Object type: Article; Object type: Conference Paper; Copyright: GeoRef, Copyright 2007, American Geological Institute.; CSAUnique: 1997-047916; AccNum: 1997-047916; ISSN: 0096-3941; CODEN: EOSTAJ}, month = {1996}, pages = {79}, publisher = {American Geophysical Union, Washington, DC, United States (USA)}, organization = {American Geophysical Union, Washington, DC, United States (USA)}, address = {United States (USA)}, keywords = {02D, 07, accelerator mass spectroscopy, C-13/C-12, C-14, carbon, chemical analysis, geochemical indicators, high-resolution methods, Isotope geochemistry, isotope ratios, isotopes, marine geology, mass spectroscopy, National Ocean Sciences Accelerator Mass Spectrometry, NOSAMS, Oceanography, Pacific Ocean, radioactive isotopes, radioactive tracers, sampling, sea water, spectroscopy, Stable isotopes, tracers, Woods Hole Oceanographic Institution}, author = {McNichol, A. P. and von Reden, K. F. and Schneider, R. J. and Key, R. M. and Jones, G. A.} } @conference {1795, title = {Stable and radiocarbon isotope measurements in the Pacific Ocean: Contributions from NOSAMS}, booktitle = {AGU/ASLO 1996 Ocean Sciences Meeting}, year = {1996}, note = {id: 960}, month = {1996}, address = {San Diego, CA}, author = {McNichol, A. P. and von Reden, K. F. and Schneider, R. J. and Key, R. M. and Jones, G. A.} } @article {967, title = {WOCE AMS Radiocarbon I: Pacific Ocean results (P6, P16, and P17)}, journal = {Radiocarbon}, volume = {38}, year = {1996}, note = {id: 38}, pages = {425-518}, abstract = {AMS radiocarbon results from the World Ocean Circulation Experiment in the Pacific Ocean show dramatic changes in the inventory and distribution of bomb-produced 14C since the time of the GEOSECS survey (8/73-6/74). Nearsurface 4C values for the eastern portion of both the northern and southern subtropical gyres decreased by 25-50\%, with the change being greater in the north. Equatorial near-surface values have increased by ca. 25\%. Changes in the 250-750-m depth range are dramatically different between the northern and southern basins. The intermediate and mode waters of the southern basin have increased by as much as 75\%o since GEOSECS. Waters of similar density in the northern hemisphere are not exposed to the Southern Ocean circulation regime and are significantly less ventilated, showing maximum changes of ca. 50\%. }, url = {https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/1918}, author = {Key, R. M. and Quay, P. D. and Jones, G. A. and McNichol, A. P. and von Reden, K. F. and Schneider, R. J.} } @conference {1609, title = {Developments at the NOSAMS Facility During 1995}, booktitle = {Symposium of Northeastern Accelerator Personnel}, year = {1995}, note = {id: 1799}, month = {1995}, address = {Durham, NC}, author = {von Reden, K. F. and Cohen, G. J. and Dalton, M. J. and Peden, J. C. and Schneider, R. J.} } @conference {1641, title = {The Hemispherical Ionizer Sputter Sources at the Woods Hole AMS Facility}, booktitle = {29th Symposium of NorthEastern Accelerator Personnel}, year = {1995}, note = {id: 1671}, month = {1995}, publisher = {World Scientific Publishing Co.}, organization = {World Scientific Publishing Co.}, address = {Durham, NC}, author = {von Reden, K. F.}, editor = {Westerfeld, C.} } @conference {1652, title = {Improvements in procedural blanks at NOSAMS: Reflections of improvements in sample preparation and accelerator operation}, booktitle = {15th International 14C Conference}, volume = {37}, year = {1995}, note = {id: 1641; 15th International Radiocarbon Conference, Glasgow, Scotland, August 15-19, 1994}, month = {1995}, pages = {683-691}, publisher = {Radiocarbon}, organization = {Radiocarbon}, author = {McNichol, A. P. and Gagnon, A. R. and Osborne, E. a and Hutton, D. L. and von Reden, K. F. and Schneider, R. J.} } @article {2343, title = {Measurements of the OX-II/OX-1 ratio as a quality control parameter at NOSAMS}, journal = {Radiocarbon}, volume = {37}, year = {1995}, note = {id: 1630}, month = {1995}, pages = {693-696}, author = {Schneider, R. J. and McNichol, A. P. and Nadeau, M. J. and von Reden, K. F.} } @conference {1684, title = {Measurements of the OX-II/OX-I ratio as a quality control parameter at NOSAMS}, booktitle = {15th International Radiocarbon Conference}, year = {1995}, note = {id: 944}, month = {1995}, address = {Glasgow, Scotland}, author = {Schneider, R. J. and McNichol, A. P. and Nadeau, M. J. and von Reden, K. F.} } @conference {1781, title = {Routine 14C AMS at 0.2\% precision - Do we need it, can it be done?}, booktitle = {109th American Chemical Society National Meeting}, year = {1995}, note = {id: 945}, month = {1995}, address = {Anaheim, CA}, author = {von Reden, K. F.} } @article {2367, title = {The Application of AMS to Organic Geochemistry--Constraints Imposed by Sample Preparation and Machine Operations}, journal = {EOS, Transactions of the American Geophysical Union}, volume = {75}, year = {1994}, note = {id: 1798}, month = {1994}, pages = {197}, author = {McNichol, A. P. and von Reden, K. F. and Schneider, R. J. and Jones, G. A.} } @article {2366, title = {Constraints Imposed by Sample Preparation and Machine Operations}, journal = {EOS, Transactions of the American Geophysical Union}, volume = {75}, year = {1994}, note = {id: 937}, month = {1994}, pages = {197}, author = {McNichol, A. P. and von Reden, K. F. and Schneider, R. J. and Jones, G. A.} } @article {2384, title = {Control and automation of the Accelerator Mass Spectrometry Facility at Woods Hole Oceanographic Institution}, journal = {Symposium of Northeastern Accelerator Personnel}, year = {1994}, note = {id: 1649}, month = {1994}, author = {Cohen, G. C. and von Reden, K. F.} } @conference {1615, title = {Do AMS measurements approach a Gaussian distribution?}, booktitle = {15th International Radiocarbon Conference}, year = {1994}, note = {id: 940}, month = {1994}, address = {Glasgow, Scotland}, author = {Jirikowic, J. L. and Schneider, R. J. and von Reden, K. F. and Jones, G. A.} } @article {2358, title = {High Precision Sea Water 14C Analyses at the National Ocean Sciences AMS Facility}, journal = {EOS, Transactions of the American Geophysical Union}, volume = {75}, year = {1994}, note = {id: 939}, month = {1994}, pages = {197}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P.} } @article {2377, title = {High-precision AMS radiocarbon measurements of central Arctic Ocean seawaters}, journal = {Nuclear Instruments and Methods in Physics Research}, volume = {B92}, year = {1994}, note = {id: 52}, month = {1994}, pages = {426-430}, author = {Jones, G. A. and Gagnon, A. R. and Schneider, R. J. and von Reden, K. F. and McNichol, A. P.} } @article {2357, title = {High-precision sea water 14C analyses by accelerator mass spectrometry. 15th International Radiocarbon Conference, Glasgow, Scotland, August 15-19}, journal = {EOS, Transactions of the American Geophysical Union}, volume = {75}, year = {1994}, note = {id: 941}, month = {1994}, pages = {197}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P.} } @article {2361, title = {The National Ocean Sciences Accelerator Mass Spectrometry Facility: Recent Developments}, journal = {EOS, Transactions of the American Geophysical Union}, volume = {75}, year = {1994}, note = {id: 938}, month = {1994}, pages = {196}, author = {Schneider, R. J. and Jones, G. A. and von Reden, K. F. and McNichol, A. P.} } @article {2360, title = {Optimized Data Analysis for AMS Radiocarbon Dating}, journal = {Nuclear Instruments \& Methods in Physics Research Section B - Beam Interactions with Materials and Atoms}, volume = {92}, year = {1994}, note = {id: 1617; PBS Record: 240; (03) FH Seguin/Mit/Cambridge, MA 02139 USA (42) English Article (44) NV547}, month = {1994}, pages = {176-181}, isbn = {0168-583X}, author = {S{\'e}guin, F. H. and Schneider, R. J. and Jones, G. A. and von Reden, K. F.} } @article {2355, title = {Performance Characteristics of the 3-MV Tandetron AMS System at the National Ocean Sciences AMS Facility}, journal = {Nuclear Instruments \& Methods in Physics Research Section B - Beam Interactions with Materials and Atoms}, volume = {92}, year = {1994}, note = {id: 1619; PBS Record: 60; (03) KF Vonreden/Woods Hole Oceanog Inst/Natl Ocean Sci Accelerator/Mass Spectrometry Facil/Woods Hole, MA 02540 USA (42) English Article (44) NV547}, month = {1994}, pages = {7-11}, keywords = {ACCELERATOR MASS-SPECTROMETER}, isbn = {0168-583X}, author = {von Reden, K. F. and Schneider, R. J. and Cohen, G. J. and Jones, G. A.} } @conference {1591, title = {Comparative study of Fe-C Bead vs. graphite target performance with the NOSAMS Facility recombinator ion source}, booktitle = {6th International Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 931}, month = {1993}, pages = {71}, address = {Canberra, Australia}, author = {Kleindinst, D. B. and McNichol, A. P. and Currie, L. A. and Jones, G. A. and Verkouteren, R. M. and von Reden, K. F. and Klouda, G. A. and Schneider, R. J.} } @conference {1644, title = {The high-precision AMS 14C program on seawater at the National Ocean Sciences AMS Facility}, booktitle = {European Community Workshop on Development of Ocean Tracer Measurements}, year = {1993}, note = {id: 1767}, month = {1993}, address = {Bremen, Germany}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P.} } @conference {1645, title = {High-precision AMS radiocarbon measurements of seawater at the National Ocean Sciences AMS Facility}, booktitle = {6th International Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 929}, month = {1993}, pages = {105}, address = {Canberra, Australia}, author = {Jones, G. A. and Schneider, R. J. and McNichol, A. P. and von Reden, K. F.} } @conference {1662, title = {Laboratory automation at the National Ocean Sciences AMS Facility}, booktitle = {6th Internation Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 927}, month = {1993}, pages = {74}, address = {Canberra, Australia}, author = {Cohen, G. J. and Hutton, D. L. and von Reden, K. F. and Osborne, E. A. and McNichol, A. P. and Jones, G. A.} } @conference {1690, title = {Methods for data screening, flagging and error analysis at the National Ocean Sciences AMS Facility}, booktitle = {6th International Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 933}, month = {1993}, pages = {83}, address = {Canberra, Australia}, author = {Schneider, R. J. and Jones, G. A. and McNichol, A. P. and von Reden, K. F. and Elder, K. L. and Kessel, E. D.} } @article {2392, title = {The National Ocean Sciences Accelerator Mass Spectrometry Facility}, journal = {WOCE Notes}, volume = {5}, year = {1993}, note = {id: 1639}, month = {1993}, pages = {5-10}, author = {Jones, G. A. and McNichol, A. P. and von Reden, K. F. and Schneider, R. J.} } @conference {1698, title = {The National Ocean Sciences Accelerator Mass Spectrometry Facility and the WOCE Hydrographic Program. Measurement of 14C in seawater by AMS}, booktitle = {Third Scientific Meeting, Oceanography Society}, volume = {95}, year = {1993}, note = {id: 1656}, month = {1993}, address = {Seattle, WA}, author = {McNichol, A. P. and Jones, G. A. and Schneider, R. J. and von Reden, K. F. and Key, R. M.} } @article {2391, title = {The National Ocean Sciences Accelerator Mass Spectrometry Facility (WOCE)}, journal = {WOCE Notes}, volume = {5}, year = {1993}, note = {id: 1651}, month = {1993}, pages = {5-10}, author = {Jones, G. A. and McNichol, A. P. and von Reden, K. F. and Schneider, R. J.} } @conference {1700, title = {The National Ocean Sciences AMS Facility at Woods Hole Oceanographic Institution}, booktitle = {6th International Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 930}, month = {1993}, pages = {46}, address = {Canberra, Australia}, author = {Jones, G. A. and Schneider, R. J. and von Reden, K. F. and McNichol, A. P. and Gagnon, A. R. and Cohen, G. J. and Osborne, E. A. and Hutton, D. L. and Kessel, E. D. and Elder, K. L.} } @conference {1703, title = {The National Ocean Sciences AMS System at Woods Hole Oceanographic Institution}, booktitle = {European Community Workshop on Tracers in Physical Oceanography}, year = {1993}, note = {id: 935}, month = {1993}, address = {Bremen, Germany}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P.} } @conference {1724, title = {Optimized data analysis for radiocarbon dating}, booktitle = {6th International Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 934}, month = {1993}, pages = {82}, address = {Canberra, Australia}, author = {Sequin, F. H. and Schneider, R. J. and Jones, G. A. and von Reden, K. F.} } @conference {1741, title = {Performance characteristics of the 3MV tandetron AMS system at the National Ocean Sciences AMS Facility}, booktitle = {6th International Conference on Accelerator Mass Spectrometry}, year = {1993}, note = {id: 936}, month = {1993}, pages = {2}, address = {Canberra, Australia}, author = {von Reden, K. F. and Schneider, R. J. and Cohen, G. J. and Jones, G. A.} } @conference {1780, title = {Role of the United States National Ocean Sciences Accelerator Mass Spectrometry Facility in Global Climate Change Studies}, booktitle = {International Symposium on Applications of Isotope Techniques in Studying Past and Current Environmental Change in the Hydrosphere and the Atmosphere}, year = {1993}, note = {id: 928}, month = {1993}, address = {Vienna}, author = {Jones, G. A. and Schneider, R. J. and von Reden, K. F. and McNichol, A. P.} } @conference {1548, title = {The 59-sample, hemispherical ionizer ion sources at the Woods Hole Accelerator Mass Spectrometer}, booktitle = {Twelfth International Conference on the Application of Accelerators in Research and Industry}, year = {1992}, note = {id: 1797}, month = {1992}, address = {Denton, Texas}, author = {von Reden, K. F.} } @conference {1558, title = {The AMS Accelerator at Woods Hole Oceanographic Institution}, booktitle = {Symposium of North Eastern Accelerator Personnel}, year = {1992}, note = {id: 1794}, month = {1992}, pages = {63-67}, publisher = {World Scientific Publishing Co.}, organization = {World Scientific Publishing Co.}, address = {Singapore}, author = {Schneider, R. J. and von Reden, K. F. and Cohen, G. J. and Jones, G. A.}, editor = {Benson, J.} } @conference {1568, title = {Application of AMS to Oceanography: Progress at the National Ocean Sciences AMS Facility (abstract)}, booktitle = {AMS Symposium Division of Nuclear Chemistry and Technology, 203rd American Chemical Society National Meeting}, year = {1992}, note = {id: 1796}, month = {1992}, author = {McNichol, A. P. and Jones, G. A. and Schneider, R. J. and von Reden, K. F.} } @article {2397, title = {The National Ocean Sciences Accelerator Mass Spectrometer for Precision C-14 at Woods Hole Oceanographic Institution -- Status and new results}, journal = {EOS, Transactions of the American Geophysical Union}, volume = {72}, year = {1992}, note = {id: 926}, month = {1992}, pages = {27}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P. and Cohen, G. J.} } @article {2396, title = {The new National Ocean Sciences Accelerator Mass Spectrometer Facility at Woods Hole Oceanographic Institution-Progress and first results (Proceedings of the 14th International Radiocarbon Conference, 1991)}, journal = {Radiocarbon}, volume = {34}, year = {1992}, note = {id: 1787}, month = {1992}, pages = {476-481}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P. and Cohen, G. J. and Purser, K. H.} } @conference {1710, title = {The new National Ocean Sciences Accelerator Mass Spectrometer Facility at Woods Hole Oceanographic Institution - Progress and First Results}, booktitle = {14th International Radiocarbon Conference 1991}, volume = {34}, year = {1992}, note = {id: 1618}, month = {1992}, pages = {476-481}, publisher = {Radiocarbon}, organization = {Radiocarbon}, author = {von Reden, K. F. and Jones, G. A. and Schneider, R. J. and McNichol, A. P. and Cohen, G. J. and Purser, K. H.}, editor = {Long, A.} } @conference {1745, title = {Planung, Aufbau und Betrieb der Woods Hole AMS Anlage}, booktitle = {AMS Symposium at Christian-Ausust University}, year = {1992}, note = {id: 1668}, month = {1992}, address = {Kiel, Germany}, author = {von Reden, K. F.} } @article {2400, title = {Rapid Analysis of Seawater Inorganic Carbon at the National Ocean Sciences AMS Facility: Progress and Preliminary Results (abstract)}, journal = {EOS, Transactions of the American Geophysical Union Meeting}, volume = {72}, year = {1992}, note = {id: 1655}, month = {1992}, author = {McNichol, A. P. and Jones, G. A. and Schneider, R. J. and von Reden, K. F. and Key, R. M.} } @conference {1722, title = {The optimization of target production for AMS}, booktitle = {14th International Radiocarbon Conference}, year = {1991}, note = {id: 922}, month = {1991}, pages = {224}, address = {Tucson, AZ}, author = {McNichol, A. P. and Gagnon, A. R. and Jones, G. A. and Schneider, R. J. and von Reden, K. F.} } @conference {1813, title = {A triple-isotope injector for Accelerator Mass Spectrometry: Conference Record of the 1991 IEEE Particle Accelerator Conference}, booktitle = {IEEE Particle Accelerator Conference}, volume = {2}, year = {1991}, note = {id: 923}, month = {1991}, pages = {878-880}, address = {San Francisco, CA}, author = {Schneider, R. J. and von Reden, K. F. and Purser, K. H.} }