@article {broek_optimization_2022,
	title = {Optimization of the LLNL/CAMS gas-accepting ion source and 1 MV compact AMS for natural abundance radiocarbon analysis of CO2},
	journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	volume = {530},
	year = {2022},
	month = {11/2022},
	pages = {1{\textendash}7},
	abstract = {The Lawrence Livermore National Laboratory {\textendash} Center for Accelerator Mass Spectrometry (LLNL/CAMS) 1 MV AMS system was converted from a biomedical AMS instrument to a natural abundance 14C spectrometer. The system is equipped with a gas-accepting hybrid ion source capable of measuring both solid (graphite) and gaseous (CO2) samples. Here we describe a series of experiments intended to establish and optimize 14CO2 measurement capabilities at natural abundance levels. A maximum instantaneous ionization efficiency of 8~\% was achieved with 3~\% CO2 in helium at a flow rate of approximately 220~{\textmu}L/min (3.5~{\textmu}g C/min). For modern materials (e.g., OX I) we measured an average of 240~{\textpm}~50 14C counts/{\textmu}g C, equivalent to a total system efficiency of approximately 3~\%. Experimental CO2 samples with F14C values ranging from 0.20 to 1.05 measured as both graphite and directly as CO2 gas produced equivalent values with an average offset of~<~2σ.},
	keywords = {Accelerator mass spectrometry, CO, Gas-accepting ion source, radiocarbon},
	issn = {0168-583X},
	doi = {10.1016/j.nimb.2022.08.012},
	url = {https://www.sciencedirect.com/science/article/pii/S0168583X22002178},
	author = {Broek, Taylor A. B. and Moreland, Kimber C. and Ognibene, Ted J. and McFarlane, Karis J. and Brown, Thomas A.}
}
@article {2633,
	title = {Blue marlin ( <i>Makaira nigricans</i>               ) longevity estimates confirmed with bomb radiocarbon dating},
	journal = {Canadian Journal of Fisheries and Aquatic Sciences},
	volume = {75},
	year = {2018},
	month = {Jan-01-2018},
	pages = {17 - 25},
	abstract = {The longevity of blue marlin (Makaira nigricans) remains unresolved. The use of fin spines and sagittal otoliths for age reading has led to unconfirmed longevity estimates near 20-30 years. Age validation has been elusive because large individuals are uncommonly caught, and a technique that can be applied to structures that provide estimates of age was absent. The use of otolith chemical signatures has been limited by sagittal otoliths that are very small-whole otolith mass of adult blue marlin rarely exceeds 10 mg for the largest fish. Recent advances in the detection limits of radiocarbon (14C) with accelerator mass spectrometry-coupled with recently acquired knowledge of marine bomb 14C signals spanning the tropical Pacific Ocean-have led to an opportunity to age blue marlin from small amounts of otolith material. In this study, otoliths from a recently collected 1245 lb (565 kg) female blue marlin at a measured 146-inch (371 cm) lower jaw fork length were analyzed for 14C. Estimated longevity was either 12-21 or 32-44 years on the basis of bomb 14C dating. Using multiple lines of evidence, it was determined that the young age scenario was most likely, with evidence for an age close to 20 years using a series of deductions in the bomb 14C dating method.},
	keywords = {Accelerator mass spectrometry, Biology, Blue marlin, Ecology, Fish measurement, FisheryLongevity, Otolith, Radiocarbon dating},
	issn = {0706-652X},
	doi = {10.1139/cjfas-2017-0031},
	url = {http://www.nrcresearchpress.com/doi/10.1139/cjfas-2017-0031http://www.nrcresearchpress.com/doi/pdf/10.1139/cjfas-2017-0031http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjfas-2017-0031},
	author = {Andrews, Allen H. and Humphreys, Robert L. and Sampaga, Jeffery D.}
}
@article { ISI:000294494900012,
	title = {Age determination of large live trees with inner cavities: radiocarbon dating of Platland tree, a giant African baobab},
	journal = {ANNALS OF FOREST SCIENCE},
	volume = {68},
	number = {{5, SI}},
	year = {2011},
	month = {AUG},
	pages = {993-1003},
	type = {Article},
	abstract = {Introduction For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens. Methods Our research extends significantly the dating of such trees to large live specimens with inner cavities. The new approach is based on collecting samples from the cavities and their subsequent radiocarbon dating. Results The giant two-stemmed Platland tree, also known as Sunland baobab, was investigated by using this new approach. AMS radiocarbon dates of the oldest sample segments originating from the two inner cavities indicate that the large stem I (364.5 m(3)) is 750 +/- 75 years old, while the much smaller stem II (136.7 m(3)) has 1,060 +/- 75 years. Results also show that stem I is still growing very fast, while the older stem II slowed down consistently its growth over the past 250 years. The complete mapping of Platland tree determined an overall wood volume of 501.2 m(3). Conclusions Dating results demonstrate that the size-age relation cannot be used for estimating accurately the age of African baobabs.},
	keywords = {Accelerator mass spectrometry, Adansonia digitata, Age determination, Growth rate, Radiocarbon dating},
	issn = {1286-4560},
	doi = {10.1007/s13595-011-0107-x},
	author = {Patrut, Adrian and von Reden, Karl F. and Van Pelt, Robert and Mayne, Diana H. and Lowy, Daniel A. and Margineanu, Dragos}
}
