T04_P01

¹⁴C Measurement of Samples for Environmental Applications at the National Environmental Isotope Facility (NEIF) Radiocarbon Laboratory, SUERC, UK.

Ascough P¹, Bompard N¹, Garnett M¹, Gulliver P¹, Murray C¹, Newton J¹, Taylor C¹

¹SUERC, University Of Glasgow, East Kilbride, United Kingdom

The National Environmental Isotope Facility (NEIF) Radiocarbon Laboratory at the Scottish Universities Environmental Research Centre (SUERC) performs radiocarbon measurement of a wide range of sample matrices for applications in environmental research. The laboratory is funded by the UK’s National Environment Research Council (NERC), as part of NERC’s Scientific Services and Facilities portfolio. Radiocarbon is applied to palaeoenvironmental, palaeoceanographic, and palaeoclimatic investigations, as well as work to understand the source, fate, turnover, and age of the carbon in the modern carbon cycle. The NEIF Radiocarbon laboratory supports users in the development and deployment of novel sampling techniques and laboratory approaches. Here, we give an overview of methods and procedures used by the laboratory to support the field collection of samples and to perform the physical and chemical pretreatment of samples. This includes in-house development of novel and/or specialised methods and approaches, such as field collection of CO₂ and CH₄, hydropyrolysis, and ramped oxidation. The sample types covered include organic remains (e.g. plant material, peat, wood, charcoal, proteins), carbonates (e.g. speleothems, foraminifera, mollusc shell, travertine), waters (dissolved organic and inorganic carbon), gases (CO₂ and CH₄), soils and sediments (including sub-fractions).

T04_P02

New Installations at ¹⁴CHRONO, Queen’s University Belfast: Ionplus MICADAS (Mini Carbon Dating System) and AGE (Automated Graphitisation Equipment) system upgrades

Barrett G¹, Allen K¹, Blaauw M¹, Reimer R¹, Reimer P¹

¹14Chrono, Queen's University Belfast, Belfast, United Kingdom

A laboratory upgrade, carried out in 2021, featured the installation of an Ionplus MICADAS, replacing a National Electrostatics Corporation 0.5MeV compact AMS system that had been in operation since 2007, and an Ionplus AGE, enhancing our existing graphitization capabilities.  Post-installation validation tests for a range of intercomparison samples, secondary standards and backgrounds are presented and demonstrate agreement with consensus values and/or long-term measurements on our previous machine.  A series of replicate measurements on 15 unknowns (bone and sediment) with well-distributed radiocarbon ages spanning approx. 170-12000 yr BP, previously measured with our NEC AMS on graphite from our zinc reduction line, is also presented; again, there is excellent agreement between both sets of measurements.

T04_P03

MAG-C63: a tree-ring standard for AD 1586

Bayliss A¹, Canti M¹, Dee M², Howard R³, Miles D⁴, Tyers C¹, Wacker L⁵

¹Historic England, London, United Kingdom, ²Rijksuniversiteit Groningen, Groningen, The Netherlands, ³Nottingham Tree-ring Dating Laboratory, Nottingham, UK, ⁴Oxford Dendrochronology Laboratory, Mapledurham, UK, ⁵ETH Zürich, Zürich, Switzerland

Standard materials are fundamental for accurate radiocarbon dating, but must be available in sufficient quantities for all AMS facilities worldwide to use as required. MAG-C63 is a beam removed from the Great Tower at St Mary Magdalen College, Oxford (51.75°N, 1.24°W) during repair works in the 1960s. It is 6.1m long, by 0.3m square and weighs over a metric tonne. It has been securely dated by ring-width dendrochronology as spanning AD 1487-1629, and has been purchased in its entirety by Historic England.

The ring selected for use as a tree-ring standard is that for AD 1586. It is 2.76mm wide, and sufficiently close to the outside of the timber that dissection in quantity is feasible, yet far enough from the outside of the timber to minimise the potential for contamination. Whole rings (earlywood and latewood) have been dissected by professional dendrochronologists, each sample being split across the ring so that it contains roughly equal amounts of earlywood and latewood. Each sample weighs approximately 50mg. We estimate that MAG-C63 will supply 40,000 such samples.

T04_P04

20 years of radiocarbon dating using the ARTEMIS facility at the LMC14 National Laboratory: review of service and research activities

Beck L¹, Caffy I¹, Delqué-Količ E¹, Dumoulin J¹, Goulas C¹, Hain S¹, Moreau C¹, Perron M¹, Setti V¹, Sieudat M¹, Thellier B¹

¹LMC14, Gif-sur-Yvette, France

In 2001, five French public organizations (CNRS, CEA, IRD, IRSN and Ministère de la Culture) signed an agreement to purchase a new Accelerator Mass Spectrometer for providing radiocarbon dating services at the national level. The Laboratoire de Mesure du ¹⁴C (LMC14) was set up in Saclay (France) around ARTEMIS, an AMS system based on a 3MV Pelletron from National Electrostatics Corporation (NEC; Middleton, Wisconsin, USA) and installed early 2003 (Cottereau et al. 2007). In 2015, the LMC14 joined the Laboratoire des Sciences du Climat et de l’Environnement, which allows to develop research projects in addition of the service activity. Since 2021, the LMC14 is a member of the IAEA Collaborating Centre “Atoms for Heritage” at the Université Paris-Saclay.

70 000 samples have been measured since then. Two-thirds of the samples have been prepared on site (wood, charcoal, carbonates, iron,…) and one-third in associated laboratories in Paris and Lyon (wood, charcoal, bones, ivory, hair,...). Over the past years, the LMC14 has participated to several international inter-comparisons (SIRI and GIRI) and has continuously improved its capabilities by developing new protocols for preparation and measurement (Dumoulin et al. 2017; Moreau et al. 2020).

In this presentation, radiocarbon dating services of the last 20 years for research laboratories, museums and environmental monitoring will be reviewed and recent results from research programs on environmental and archaeological studies will be highlighted.

T04_P05

Facility Report: NOSAMS operations and the new MICADAS

Broek T¹, Roberts M¹, Longworth B¹, Burton J¹, Crossen A¹, Cruz A¹, Elder K¹, Gagnon A¹, Gospodinova K¹, Handwork S¹, Hansman R¹, Kurz M¹, Lardie Gaylord M¹, Trowbridge N¹, Xu L¹, Lang S¹

¹National Ocean Sciences Accelerator Mass Spectrometry Facility, Woods Hole, United States

The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at Woods Hole Oceanographic Institution provides ¹⁴C-AMS analyses and expertise in support of the US oceanographic and earth science communities. NOSAMS measures on average 7,300 unknowns per year on two unique AMS instruments. The CFAMS system, commissioned in 2006, is based around a 500 kV NEC Pelletron tandem accelerator and a modified 134 position NEC MC-SNICS ion source and currently serves as the primary instrument for client samples. In late 2021, the original NOSAMS 3 MV USAMS Tandetron instrument, in operation since 1992, was decommissioned and replaced in 2022 with an IonPlus 200 kV MICADAS with gas interface and associated sample introduction peripherals (elemental analyzer and carbonate handling system). Here, we provide an update on the NOSAMS facility AMS systems and present results from the initial implementation and operation of the MICADAS, including quantification of system accuracy and precision with both solid and gaseous samples, comparison of data from materials measured as both graphite and CO₂ gas, performance of small (<100 µg C) solid samples, and modifications to solid sample targets. We also discuss integration of the new system into our laboratory workflows, data reduction software, and database system.

T04_P06

Performance and inter-comparison tests of the MICADAS at the radiocarbon laboratory of Lanzhou University, China

Cao H¹, Zhou A¹, Wang Z¹

¹College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China

Radiocarbon laboratory of Lanzhou University was primitively organized in 1987, experienced long-term complement and development, and introduced a compact accelerator mass spectrometer (AMS)—a 200-KV mini carbon dating system (MICADAS) from Ionplus AG in 2018, together with an auto graphitization equipment (AGE III). The laboratory has for a long time prepared graphite targets for radiocarbon dating of organic materials including charcoal, bone, plant remains, sediments. Herein, we give an overview of the operating status and performance of the dating facility. Fifteen sets of organic materials collected from archaeological sites in northwest China were selected for an inter-comparison study involving the participation of four specialist laboratories, the pretreatment, graphite preparation, and AMS testing of the samples were performed, respectively. The ¹⁴C dating results showed a high degree of consensus for the homogenized samples. The long-term measurement of the standard and blank samples indicated the that the results for MICADAS in Lanzhou University were accurate and stable and of high sensitivity, the mean background is about 47,000 years. The radiocarbon laboratory of Lanzhou University could provide stable and accurate ¹⁴C dating results, and has provided a large number of ¹⁴C dates for archaeological/environmental samples.

T04_P07

Recent Results from the Office of Archaeological Studies Plasma Oxidation Laboratory, Santa Fe, New Mexico

Cox J¹, Rowe M¹, Blinman E¹, Jones S¹, Welte C^2,3

¹Office Of Archaeological Studies, Center for New Mexico Archaeology, Santa Fe, United States, ²Laboratory of Ion Beam Physics, ETH Zűrich, HPK, H29, Otto-Stern-Weg 5, CH-8093 , Zűrich, Switzerland, ³Geological Institute, ETH Zürich, NO, Sonneggstrasse 5, CH-8092 , Zűrich, Switzerland

The plasma technique was originally developed in conjunction with dating rock art by Marvin Rowe at Texas A&M University. After retiring, Dr. Rowe moved to Santa Fe, NM where he helped establish our current plasma oxidation laboratory in 2013. Advantages of the plasma technique include the ability to produce very small samples for processing (20-100 µg carbon), no necessity for removal of carbonates or oxalates due to operational temperatures usually below 50°C, virtually non-destructive sampling, removing minute amounts of surface carbon and the ability to collect multiple dates from a single sample. In recent years, the Plasma Oxidation Laboratory has processed a wide variety of materials. In addition to using the plasma with standards, other materials include an alleged Picasso painting, multi-layered extractions of soot, a probable Lewis and Clark iron axe head, Egyptian and Pecos River mummies and of course, rock art.

T04_P08

A new automatic sample preparation line for radiocarbon measurements on the carbonaceous fractions of atmospheric aerosol

Crova F¹, Barone S^2,3, Calzolai G², Chiari M², Fedi M², Forello A^1,3, Liccioli L², Lucarelli F^2,3, Massabò D⁴, Nava S^2,3, Prati P⁴, Valentini S¹, Valli G¹, Vecchi R¹, Bernardoni V¹

¹Department of Physics, Università degli Studi di Milano, and INFN-Milano, Milan, Italy, ²INFN-Firenze, Sesto Fiorentino, Italy, ³Department of Physics and Astronomy, Università degli Studi di Firenze, Sesto Fiorentino, Italy, ⁴Department of Physics, Università degli Studi di Genova, and INFN-Genova, Genoa, Italy

Radiocarbon measurements on organic and elemental carbon fractions are a powerful tool for separating the contribution due to fossil fuel combustion, biomass burning and natural sources to the emission of carbonaceous aerosols in the atmosphere [Szidat et al., 2006].

At INFN-LABEC in Florence, radiocarbon measurements on separated carbon fractions have been so far performed exploiting proper thermal protocols and a dedicated sample preparation line, which however is entirely manually operated and suitable for samples of about 200 μgC [Bernardoni et al., 2013; Calzolai et al., 2011].

Recent developments at LABEC now allow the ¹⁴C-AMS measurements of significantly smaller samples (about 50 μgC) mainly thanks to a new graphitization line [Fedi et al., 2020]. Following this experience, a new sample preparation line dedicated to atmospheric aerosol samples was designed and realised as part of the INFN-ISPIRA experiment (Integration of experimental methodologies for carbonaceous aerosol research) in Milan. The line scheme remains unchanged, but innovative elements allow the preparation of small-size samples in a partially automatic way, thanks to the automatic switch of combustion gas (He/Oxygen) and temperature ramps control in the different combustion phases, and the automatic maintenance of the temperature inside the cold traps for the CO₂ purification and collection. Thanks to these upgrades a higher number of samples will be prepared, and smaller samples (e.g., collected with higher temporal resolution or at remote sites) will be analysable, thus allowing to obtain more representative data.

The poster will present the features of the new experimental setup and the first tests.

T04_P09

Capabilities, Procedures, and Summary Statistics of the MICADAS and GIS at ACE Isotope Laboratory, Northern Arizona University

Ebert C¹, Schuur E¹, Kaufman D¹, Brown J¹, Propster J¹, Kelley A¹, Bright J¹, Carbone M¹, McKay N¹, Koch G¹

¹Northern Arizona University, Flagstaff, United States

The Arizona Climate and Ecosystems (ACE) Isotope Laboratory at Northern Arizona University brought a MICADAS online on June 1, 2021. Our lab includes a Gas Ion Source (GIS) with a Carbonate Handling System (CHS2) and Automated Graphitization Equipment (AGE3), as well as manual graphitization equipment and a wet lab for sample pretreatment. In one year since measurement of unknown samples began, we have analyzed 1,553 graphite samples (including 967 unknown graphite samples) and 1098 gas samples (including 647 unknown gas samples). These unknowns include a variety of sample types: plant materials, atmosphere, ecosystem respiration samples, carbonates, megafauna coprolites, organic and inorganic soils, and dissolved organic carbon.

Our facility supports specific research projects of the coauthors and other NAU researchers, with a particular focus on Arctic carbon and its potential as a feedback to climate change. Other research includes: geochronology of sediment and lake cores, tree physiology, and ecosystem science.

Our MICADAS laboratory has performed similar to other AMS laboratories. During 202 graphite replications of SRM 4990C (Oxalic Acid II), the standard deviation is 2.3 permil. After running 107 OX-II replicates with the GIS, the standard deviation is 7.8 permil. Other SRMs demonstrate similar precision. Across 112 graphite radiocarbon blank repetitions, the average age is 50,200 years. 154 GIS blank replicates had an average age of 38,900 years.

T04_P12

A database of NERC Radiocarbon age measurements determined by accelerator mass spectrometry

Garnett M¹, Gulliver P^1,2, Ascough P¹

¹NEIF Radiocarbon Laboratory, East Kilbride, United Kingdom, ²SUERC Accelerator Mass Spectrometry Laboratory, East Kilbride, United Kingdom

Radiocarbon measurements undertaken by the NERC Radiocarbon Laboratory using accelerator mass spectrometry are now freely available on a new database hosted on the World Wide Web. The measurements cover a wide range of sample types undertaken for Earth and environmental science research projects supported by the United Kingdom’s Natural Environment Research Council (NERC). Sample types include but are not restricted to, organic remains, soils, sediments, carbonates, dissolved organic and inorganic carbon, and carbon dioxide. Currently, the online database contains radiocarbon ages for approximately 2000 individual samples reported between 2006 and 2010, but it is envisaged that this will expand considerably as more data are made available. Contextual information such as sampling location and associated publications are provided where available, and searches can be performed on sample location, type, project number and publication code. This new database compliments an existing, publicly available database of measurements performed using radiometric methods by the laboratory which has recently been expanded to present over 2000 measurements. It is hoped that this archive will prove useful to workers in the community who would benefit from greater availability of measurements for the purposes of performing meta-analyses, and/or synthesis of larger datasets.

T04_P13

First status report on ¹⁰Be and ²⁶Al sample preparation techniques at the IHEG, CAGS AMS laboratory (Xiamen, China)

Hui Z¹

¹Chinese Academy Of Geological Sciences, Shijiazhuang, China

The Institute of Hydrology and Environmental Geology (IHEG), Chinese Academy of Geological Sciences(CAGS) organized a research group engaged in radionuclides analysis and dating by AMS in 2015, then purchased its first multi-element AMS facility (1MV, HVEE) in 2017. Unfortunately, this facility has not been installed yet. The 10Be and 26Al sample preparation laboratory spent the better part of 2020 establishing pretreatment protocols, and streamlining sample processing, included optimizing extraction and purification of quartz, ion exchange chromatography methods, minimizing backgrounds. Here, we present an overview of sample processing protocols and results from measured standards, reference, and blank materials.

T04_P14

Development of the PATRIC14 project on the ARTEMIS AMS facility for the dating of low-carbon content cultural heritage materials.

Moreau C¹, Thellier B¹, Hain S¹, Beck L¹, Caffy I¹, Delque-Kolic E¹, Dumoulin J¹, Goulas C¹, Perron M¹, Setti V¹, Sieudat M¹

¹Laboratoire de Mesure du Carbone 14 (LMC14), LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France

The development of Accelerator Mass Spectrometry (AMS) dating technique has made it possible to considerably reduce the quantity of material necessary to carry out a dating. However, for archaeological works or objects low in carbon, the quantities of material to be sampled often remain too voluminous for dating to be considered. This is particularly the case for certain old ferrous objects for which previous studies have revealed very low carbon contents. This is also the case with other materials such as plaster and stucco, materials for sculptural and architectural creation, widely used since the ancient periods of Archeology and Art History. Currently, their dating is based solely on stylistic criteria, which sometimes leads to debate. The objective of the PATRIC14 project is therefore to develop a new instrumental device which will be installed on the ARTEMIS facility, in order to date low carbon content material. The aim is to add a gas ion source to the ARTEMIS facility and to develop a specific gas transfer module - compatible with the LMC14 sample preparation benches - allowing the injection in the AMS of samples directly in gaseous form, avoiding the transformation into solid graphite as at present. This solution will thus make it possible to considerably reduce the quantity of carbon necessary to carry out dating by AMS. The first applications using the new equipment will be carried out in collaboration with the partners of the project in different fields: archaeometry (LAPA), research and restoration (C2RMF) and museum (Louvre).

T04_P15

Aarhus AMS Centre – Status report

Olsen J¹

¹Aarhus University, Aarhus, Denmark

A status report of the installation and use of the newly installed high intensity sputter ion source SO 110C is presented. The source produced a pre-acceleration ¹²C beam of above 200 μA during demonstration . Here performance data of different source settings is shown together with machine performance for charge state +1 of a pre-acceleration ¹²C beam between 80 - 100 μA.

T04_P16

Comparative features of BINP AMS and MICADAS facilities, working at AMS Golden Valley, Russia.

Petrozhitskiy A^1,2,3, Parkhomchuk E^2,3,4, Ignatov M^2,3, Kuleshov D^2,3, Kutnyakova L³, Konstantinov E¹, Parkhomchuk V^1,2

¹Budker Institute Of Nuclear Physics Siberian Branch Russian Academy Of Sciences, Novosibirsk, Russian Federation, ²Novosibirsk State University, AMS Golden Valley, Novosibirsk, Russian Federation, ³Institute of Archaeology and Ethnography Siberian Branch Russian Academy Of Sciences, Novosibirsk, Russian Federation, ⁴Boreskov Institute of Catalysis Siberian Branch Russian Academy Of Sciences, Novosibirsk, Russian Federation

The AMS Golden Valley radiocarbon analysis laboratory is equipped with two accelerator mass spectrometers: BINP (Budker Institute of Nuclear Physics) AMS facility and MICADAS-28, and two graphitization systems: AGE-3 and Absorption-catalytic setup, developed in Boreskov Institute of Catalysis (ACS BIC). The laboratory provides routine ¹⁴C analyses of various samples: collagen, cellulose, humic acids, carbonates from sediments etc. The main focus of the laboratory is to determine the age of archaeological artifacts by radiocarbon dating.

Detailed description and characteristics of BINP AMS facility will be presented compared with that one’s of  MICADAS. In 2022 the AMS Golden Valley laboratory took part in the Glasgow International Radiocarbon Inter-comparison (GIRI). The samples were graphitized on the AGE-3 (4 targets from each sample, 8 targets from bone sample K) and subsequently measured on both AMS facilities. A comparison of the results from two series of experiments: AGE-3 + MICADAS-28 and AGE-3 + BINP AMS will be given.

T04_P17

CEDAD at the University of Salento: twenty years of operations and new perspectives

Calcagnile L¹, D'Elia M¹, Maruccio L¹, Scrimieri L¹, Quarta G

¹CEDAD-University Of Salento, Lecce, Italy

The Centre for Applied Physics, Dating and Diagnostics (CEDAD) was established in 2001 at the University of Salento in Lecce to be a National Centre in Italy for radiocarbon dating by Accelerator Mass Spectrometry. The Centre is based on a 3 MV TandetronTM accelerator manufactured by High Voltage Engineering Europa B.V.. The system initially equipped only with the ¹⁴C dating AMS beamline, has been  significantly updated over the years and in the frame of different projects with the installation of other five beamlines dedicated to IBA (Ion Beam Analysis) both in vacuum and in air, ion irradiation and nuclear microprobe. A dedicated, multipurpose beamline has been also designed and built in-house for the AMS detection of rare nuclides from 10B to actinides. From the instrumental point of view the last upgrade consisted in the installation of a hybrid (solid and gas) ion-source coupled with the AMS system and a IRMS spectrometer (Thermo Fischer Delta V Plus). Samples with masses in the microgram range are routinely measured for applications spanning from archaeological to environmental sciences. Recently the set-up has been further improved by the installation of a gas-bench interface allowing the analysis of DIC from water samples and carbonates. Application fields spanning from archaeology, forensics, Earth and marine sciences to the analysis of sample of industrial interest (such as bio-fuels and biopolymers) are also reviewed.

T04_P18

Carbonus, the new carbon AMS facility devoted to paleoclimate studies at the University of Salamanca

Quintana Arnés B¹,  Rodríguez Álvarez A¹, Ausín B¹, Borrego D¹, Flores J¹

¹Universidad De Salamanca, Salamanca, Spain

Carbonus is the new ¹⁴C facility at the University of Salamanca (Spain). It is made up of a MICADAS accelerator mass spectrometer and a clean chemical laboratory devoted specifically to prepare carbon samples and equipped with an AGE3, made by Ionplus, which is coupled to an Elemental Analyser (EA). Additionally, ultra low-level LSC counting preceded by a benzene synthesis procedure is available to determine absolute ¹⁴C in large samples. The main purpose of this accelerator facility is to date samples of interest in paleoclimate studies. Being set in before the COVID pandemic and once several severe issues due to the building electrical current were solved, Carbonus is ready to start operation. In this work, the background study aimed to characterize the facility performance as well as the first results on Holocene marine sediments from the Powell 2020 Antarctic campaign will be presented. Previously, the facility will be described and the lessons learnt from the different issues that affected the Micadas operation will be given.

T04_P19

Fifteen years of the Centro Nacional de Aceleradores (CNA) radiocarbon facility.

Santos Arévalo F¹, Gutiérrez J¹, Gómez Martínez I¹, Galván Moreno J¹, Díaz Francés I¹, García León J¹, Peruchena Fernández J¹

¹Centro Nacional de Aceleradores (University of Seville, CSIC, Junta de Andalucía), Seville, Spain

The radiocarbon dating laboratory at CNA was the first one in Spain based on AMS measurements and started operation in 2007 based on a 1MV HVEE multielemental AMS system and a completely manual graphitization line for five samples.  Fifteen years later, the facility has experimented changes both in the AMS system and the sample preparation lab.  The most significant one was the installation of a Micadas system in 2012, which since then has been routinely used for the AMS measurements.  Besides, the sample preparation lab has upgraded significantly, and it is now equipped with two automatic graphitization lines (AGE2 and AGE3) for seven samples each, coupled to an Elemental Analyzer and a Carbonate Handling System, as the most relevant elements.  Sample pretreatments have also evolved in time.  In this paper we will give an overview of the current situation of the radiocarbon facility, briefly discussing the sample preparation procedures.  Some significant research and application projects will also be covered.

T04_P20

A Brief History of Sulfur Isotope Analysis in Archaeological Bone Collagen at the SUERC Radiocarbon Laboratory.

Sayle K¹, Dunbar E², Hamilton D³

¹University of Glasgow, SUERC, East Kilbride, Scotland, ²University of Glasgow, SUERC, East Kilbride, Scotland, ³University of Glasgow, SUERC, East Kilbride, Scotland

The use of multi-isotopic analysis (δ¹⁵N, δ¹³C and δ³⁴S) of archaeological bone collagen to assist in the interpretation of diet, movement and mobility of prehistoric populations has been gradually increasing. Sulfur analysis has proven to be an extremely valuable additional tool for distinguishing between individuals who have obtained their food from terrestrial, marine and/or freshwater resources, which in turn can affect their radiocarbon ages.

Sulfur concentrations in bone collagen are generally very low (ca. 0.2–0.3%) compared to nitrogen and carbon concentrations (ca. 15% and 40%, respectively). This has presented an analytical challenge for simultaneous δ¹⁵N, δ¹³C and δ³⁴S analysis and resulted in the need to analyse one sample for δ¹⁵N and δ¹³C and a second, larger sample, for δ34S to obtain sufficient signals and data precision. Consequently, this led to longer analytical times and higher costs.

Recent advances in Elemental Analysis Isotope Ratio Mass Spectrometry (EA-IRMS) have opened up the potential for rapid, accurate and precise analysis at concentrations less than 10 µg of sulfur, whilst simultaneously acquiring data for and δ¹⁵N and δ¹³C, meaning samples can be analysed more rapidly and at a lower cost. Furthermore, depending on preservation, significantly smaller amounts of bone is required for analysis, and hence, less archaeological material is destroyed.

This poster will chart the development of sulfur isotope analysis in archaeological bone collagen at the SUERC Radiocarbon Laboratory over the past decade.

T04_P21

A home-made semiautomatic graphitization device for AMS ¹⁴C dating at NTUAMS Lab

Shen T¹, Chang H¹, Li H¹

¹Department of Geosciences, National Taiwan University, Taipei, Taiwan

We have built up a semiautomatic graphitization system with 6 units. The system can be connected with EA and IRMS or run alone with gas inlet. Once the CO₂ is transferred into the reactor and measured its pressure, pure H₂ is added into the reactor with 2.2 times of PCO₂. The CO₂ will be reduced to graphite at 550°C. This 6-unit reaction system costs < US$30K. Up to date, four background CO₂ gas input samples show that the ¹⁴C/¹²C values of the graphite samples made by the reaction system range from 1.56∙10^-15 to 3.06E^-15, indicating very low background of the system. In the first batch test, six coal background (BKG) samples through the EA to the graphitization reactors yielded the ¹⁴C/¹²C values of the produced graphite samples ranging from 6.9E-15 to 4.13∙10^-14. The higher ¹⁴C/¹²C values are mainly attributed to weak ¹²C current due to poor quality of the graphite. The second batch test contained 3 OXII, 2 BKG and 3 FIRI-M (4th inter-comparison sample with consensus age of 11139 yr BP). The measured ¹⁴C ages of the three FIRI-M are 11514±142 (¹²C current = 5.7 μA), 11653±307 (0.53 μA) and 11968±835 yr BP (0.076 μA), respectively. The age uncertainty increases with weakness of the graphite target strength. Nevertheless, the system is under refining with more tests. With the low cost, the system is able to provide convenient and effective graphitization for organic samples.

T04_P22

The Radiocarbon and Tritum measurments at GXNU-AMS facility

Shen H^1,2, Tang J^1,2,  Shi S¹, Zhang G¹, Wang  L¹,  Chen D¹, Qi L¹, He M³, Sasa K⁴,  Jiang S⁴

¹Guangxi Normal University, Guilin, China, ² Guangxi key laboratory of nuclear physics and nuclear technology, Guilin, China, ³China Institute of Atomic Energy, Beijing, China, ⁴ University of Tsukuba, Tsukuba, Japan

A single-stage accelerator mass spectrometer (GXNU-AMS) developed for Radiocarbon and Tritium measurements was installed and commissioned at Guangxi Normal University in 2017. During several years of operation, its performance has been continuously improved and applied in multidisciplinary fields. Currently, the measurement sensitivity for radiocarbon and tritium is ¹⁴C/¹²C ~ (2.23±0.045) ×10-15 and ³H/¹H ~ (1.23±0.17)×10-16, respectively, and the measurement accuracy is ~ 0.6%, which can meet the measurement requirements in the fields of life sciences and archaeology applications. This study presents the performance characteristics of GXNU-AMS and several interesting application studies.

T04_P23

Safe delivery of graphite targets to AMS facilities, to minimize contamination. The final step of BRAVHO laboratory at Bologna University

Tassoni L¹, Kromer B², Friedrich R³, Wacker L⁴, Friedrich M⁵, Paleček D¹, Pelloni E¹, Talamo S¹

¹University of Bologna, Bologna, Italy, ²Heidelberg University, Heidelberg, Germany, ³Curt-Engelhorn-Centre Archaeometry, Mannheim, Germany, ⁴Laboratory of Ion Beam Physics, ETH, Zurich, Switzerland, ⁵University of Hohenheim, Stuttgart, Germany

Nowadays, most laboratories can reliably remove contamination during the pretreatment of organic samples (e.g. bones, charcoal or trees) thanks to several methods commonly used by the radiocarbon community. However, what about the final step, the storage of graphite? Rarely do the laboratories produce their own graphite and ship them as pressed targets to AMS facilities for measurement. Pressed graphite in aluminium targets is vulnerable to contamination and during the shipment or storage there can be an introduction of exogenous carbon.

Here we report a test on some archaeological samples materials (i.e. charcoal, bones and trees) from different environments and different time periods (from the Modern Age to the Middle Paleolithic period) which were transformed into graphite, with the AGE III (Automated Graphitization Equipment, IonPlusAG, Switzerland), pressed into targets at the BRAVHO lab (Bologna Radiocarbon laboratory devoted to Human Evolution) and sent to two different AMS laboratories to be dated. The two AMS labs chosen for this experiment are the Curt-Engelhorn-Centre Archaeometry, Mannheim, Germany and the Laboratory of Ion Beam Physics, ETH, Zurich, Switzerland. The experiment shows that it is possible to produce graphite in a sample preparation laboratory and send it safely to an AMS laboratory for measurement in a short time without significant contamination. Close cooperation and coordination between our chemical laboratory and AMS facilities, high standards in contamination removal and efficient measurement planning enabled us to obtain reliable outcomes within short times.

T04_P24

Status report on small sample measurements with ECHoMICADAS AMS facility: 6 years of data processing and statistical results.

Thil F¹, Tisnérat-Laborde N¹, Hatté C^1,2, Noury C¹, Phouybanhdyt B¹

¹Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris Saclay, F-91198, Gif Sur Yvette, France, ²Division of Geochronology and Environmental Sciences, Institute of Physics, Silesian University of Technology, 44-100 Gliwice, Poland

In 2015, a new AMS facility, the ECHoMICADAS was installed in the Laboratoire des Sciences du Climat et de l’Environnement (LSCE) at Gif-sur-Yvette, France. Equipped with a hybrid source, it allows the analysis of solid or gas samples for ¹⁴C measurement. This equipment is completed with several peripheral instruments. For solid measurement, 2 graphitisation systems are used: the homemade Graphitisation line (GéGé) to graphitize CO₂ and an Automated Graphitization Equipment (AGE3) for most of organic samples. For CO₂ gas measurement, the Gas Interface System (GIS) injects a mix of CO₂ and He into the source and allows to couple an elemental analyzer (EA) for organic sample, a tube cracking system for pure CO₂, and more recently a Carbonate Handling System (CHS2) for carbonates or dissolved inorganic carbon.

This presentation focuses on measurement of small samples and how to process raw data. It is based on both CHS2-GIS and EA-GIS examples. We will describe how the data are processed, using a combination of the calculation made in Bats software [a] and of the models which were chosen to consider the constant and the cross contamination [b]. Since 2016, measurements on blanks and standards allow to yield enough statistics to estimate, even before its measurement what will be the age uncertainty, based on several expected parameters: the weight (or quantity of carbon), the current, the sample age, the measurement duration, and the chemical protocol which can induce different contaminations.

[a] Lukas Wacker et al, NIMPR 2010

[b] Salazar et al, NIMPR 2015

T04_P25

A summary of quality assurance samples at the SUERC Radiocarbon Laboratory

Tripney B¹, Dunbar E¹, Naysmith P¹

¹Scottish Universities Environmental Research Centre, East Kilbride, United Kingdom

The SUERC Radiocarbon Laboratory reports approximately 3000 unknown samples per year with an additional 1200 samples processed for quality assurance (QA) purposes.  In addition to the primary OXII standard (SRM-4990C) required for AMS batch normalisation, secondary known-age standards (TIRI A and SIRI N) have been used to evaluate batch quality over many years, while interglacial wood (VIRI K), geological-age carbonate (TIRI F) and mammoth bone are employed as ‘background’ standards for age calculation.

Further ‘in-house’ tertiary standards are used to monitor specific processes. Measurements on a 2007 new make spirit are used to promote confidence in the preparation of whisky samples, with kerosine providing a background check for the method. Starting in 2003 a series of known-age bones have been used to monitor collagen extraction, while repeat preparations of a cremated bone sample are a more recent addition.

Summary results for these samples are given, setting them within the context of the laboratory QA system.

T04_P26

Production of radiocarbon micro-samples at ANSTO

Hua Q¹, Levchenko V¹, Smith A¹, Varley S¹, Williams A², Yang B¹, Zoppi U³

¹Australian Nuclear Science & Technology Organization (ansto), Lucas Heights, Australia, ²Deceased, 9th February 2021., , , ³Deceased, 27the March 2016., ,

ANSTO’s Centre for Accelerator Science has been providing radiocarbon analyses for nearly three decades using our solid sample ion sources. From the beginning, there was a need to refine capability for ever smaller samples. This paper summarises the various approaches we have developed to deal with samples containing just a few micrograms of carbon (µgC). Initially we began optimising our ‘conventional’ graphitisation furnaces. We decreased the reaction volume to ~ 3.5 mL and investigated various catalysts and means of activating them. Today, we operate a bank of 24 conventional furnaces for samples containing >10 µgC. In 2003 we developed novel, Laser Heated Furnaces using a focused infrared laser to directly heat the Fe catalyst in a quartz crucible, with temperature measured indirectly by infrared thermometry. These units have a reaction volume of ~0.25 mL. Smaller volumes allow a higher initial pressure for small amounts of CO₂, improving the graphite yield. Efficient trapping of by-product H₂O and careful selection of the catalyst are also key to optimising graphitisation of micro-samples. By localising the heated region within the reaction volume, the addition of extraneous carbon is minimised and samples containing just 1-2 µgC are routinely prepared.

The fabrication approach developed for the LHF was adapted to a new type of miniaturised furnace, namely micro-conventional furnaces (MCF). These furnaces have a minimum reaction volume of 0.9 mL with a small tube furnace for catalyst heating. Variable temperature cold traps have been developed to optimise sample processing with samples containing 5 µgC routinely prepared.

T04_P27

Status of the AMS-dating at Radiocarbon laboratory of the Institute of geography RAS

Zazovskaya E¹, Shishkov V¹, Turchinskaya S, Cherkinsky A²

¹Institute of geography RAS, Moscow, Russian Federation, ²University of Georgia, CAIS, Athens, USA

The Radiocarbon Dating Laboratory (Lab code IGAN) was founded at the Institute of Geography of the Russian Academy of Sciences in the 1970s and has since continuously dated different carbon-containing materials using the liquid scintillation counting method. In 2015, our Laboratory has acquired the Ionplus automated graphitization system – AGE 3, together with a Vario Isotope Cube CHNS elemental analyzer. In early 2018 (with the help of Ionplus specialists), an isotope ratio mass spectrometer was coupled to the AGE 3 and our Laboratory staff members attended a brief training. Graphite ¹⁴C/¹³C ratios were measured using the CAIS 0.5 MeV Accelerator Mass Spectrometer at the Center for Applied Isotope Studies (CAIS), University of Georgia. Anthracite and phthalic anhydride were used as BG for graphitization. The BG results consistently give ages between 44,000 and 49,000 BP for anthracite and 46,000 and 52,000 BP for phthalic anhydride. OXII and OX1 are used as the modern standard for graphitization. An inter-laboratory comparison between IGAN and CAIS was conducted in respect to graphitization and dating of materials of known ages, with the results obtained being highly comparable. During the work of AGE-3 system more than 5000 graphites of high quality were obtained from such carbon-bearing materials as coal, wood (cellulose), human and animal bones, soils, sediments of different genesis, peats, fouling from ceramic material, fabric. Samples for graphitization are prepared according to accepted protocols. The  methods modified in the IGRAN laboratory are also used when dating the organic matter of soils.

T04_P28

C-14 AMS data quality assessment: How it’s done at the Rafter Radiocarbon Laboratory

Zondervan A¹, Turnbull J¹, Ginnane C¹, Norris M, Dahl J¹, Lewis C¹

¹GNS Science, Lower Hutt, New Zealand

The Rafter Radiocarbon Laboratory, in operation since 1951, transitioned from decay counting to AMS in the 2nd half of the 1980s. In the decades since, numerous improvements were made to sample preparation lines and protocols and to AMS system hard- and software. The most recent of these were the development of high-precision measurement of ¹⁴C in atmospheric CO₂, high throughput capacity for modern tree ring samples via accelerated solvent extraction, selective combustion of organics through ramped pyrolysis, and establishment of a custom protocol for tiny macrofossil samples. Presently, a new graphitisation system is under construction for reliable preparation for 0.05—0.15 mg C samples. It has been our longstanding practice to aim to report each ¹⁴C analysis with an error value that captures all sources of uncertainty, not just the Poisson counting error.

We tune XCAMS, our present AMS system, on a graphitisation blank and IAEA-C6 sucrose. Oxalic-acid-I (Ox-I) remains our primary standard and every batch measurement on ≤ 40 cathodes contains at least 6 of those. Raw AMS data are normalized to Ox-I per batch, while the blank correction for the samples in that batch is evaluated from blanks during the most recent 6—12 months. Lastly, repeated analysis of a few key radiocarbon inter-comparison materials allows us to estimate the residual, i.e. non-Poisson uncertainty, specific to each sample type and size (range). We will present results for all control materials, to highlight dependencies on date of preparation, preparation method, and sample size.