scholarly journals Update on the Performance of the SUERC In Situ Cosmogenic 14C Extraction Line

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1288-1294 ◽  
Author(s):  
R H Fülöp ◽  
P Naysmith ◽  
G T Cook ◽  
D Fabel ◽  
S Xu ◽  
...  
Keyword(s):  
Extraction System ◽  
Quartz Sample ◽  
Gas Cleaning ◽  
Preliminary Results ◽  
University Of Arizona ◽  
Average System ◽  
The University ◽  
Combustion Technique ◽  
Continuous Running

In this paper, we describe improvements to the in situ cosmogenic radiocarbon extraction system at SUERC made since 2004, highlighting the factors that potentially control the reduction of analytical variability. We also present new results on system blanks and of measurements of in situ14C in shielded quartz and a surface quartz sample used at the University of Arizona as an in situ14C standard (PP-4). The SUERC in situ14C extraction system was built in 2001 and is based on a combustion technique following the design of the extraction system at the University of Arizona. Our preliminary results suggest that the continuous running of the extraction system and the monitoring of gas collecting time and of the temperature of the cryogenic traps used in the gas cleaning steps are key to maintaining low and stable system blanks. Our latest average system blank is 2.02 ± 0.23 x 10514C atoms. This is consistent with those recently published by the University of Arizona and ETH in situ14C labs. Measurements of in situ14C concentrations in sample PP-4 yield an average of 3.82 ± 0.23 x 105 atoms g–1 quartz, again consistent with published values.

scholarly journals Preliminary Results for the Extraction and Measurement of Cosmogenic in Situ 14C from Quartz

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 201-206 ◽  
Author(s):  
P Naysmith ◽  
G T Cook ◽  
W M Phillips ◽  
N A Lifton ◽  
R Anderson
Keyword(s):  
Vacuum System ◽  
Quartz Sample ◽  
Erosion Rates ◽  
The Past ◽  
Cosmogenic Nuclide ◽  
Lithium Metaborate ◽  
University Of Arizona ◽  
Efficient Extraction ◽  
The University

Radiocarbon is produced within minerals at the earth's surface (in situ production) by a number of spallation reactions. Its relatively short half-life of 5730 yr provides us with a unique cosmogenic nuclide tool for the measurement of rapid erosion rates (>10−3 cm yr−1) and events occurring over the past 25 kyr. At SUERC, we have designed and built a vacuum system to extract 14C from quartz which is based on a system developed at the University of Arizona. This system uses resistance heating of samples to a temperature of approximately 1100° in the presence of lithium metaborate (LiBO2) to dissolve the quartz and liberate any carbon present. During extraction, the carbon is oxidized to CO2 in an O2 atmosphere so that it may be collected cryogenically. The CO2 is subsequently purified and converted to graphite for accelerator mass spectrometry (AMS) measurement. One of the biggest problems in measuring in situ 14C is establishing a low and reproducible system blank and efficient extraction of the in situ 14C component. Here, we present initial data for 14C-free CO2, derived from geological carbonate and added to the vacuum system to determine the system blank. Shielded quartz samples (which should be 14C free) and a surface quartz sample routinely analyzed at the University of Arizona were also analyzed at SUERC, and the data compared with values derived from the University of Arizona system.

scholarly journals A Simplified In Situ Cosmogenic 14C Extraction System

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1236-1243 ◽  
Author(s):  
Jeffrey S Pigati ◽  
Nathaniel A Lifton ◽  
A J Timothy Jull ◽  
Jay Quade
Keyword(s):  
Extraction System ◽  
University Of Arizona ◽  
The University ◽  
New System ◽  
Design Construction

We describe the design, construction, and testing of a new, simplified in situ radiocarbon extraction system at the University of Arizona. Blank levels for the new system are low ((234 ± 11) x 103 atoms (1 σ; n = 7)) and stable. The precision of a given measurement depends on the concentration of 14C, but is typically <5% for concentrations of 100 x 103 atoms g–1 or more. The new system is relatively small and easy to construct, costs significantly less than the original in situ14C extraction system at Arizona, and lends itself to future automation.

Current Performance and Preliminary Results of a New 14C Extraction Line for Meteorites at the University of Bern

Radiocarbon ◽  
2017 ◽  
Vol 60 (2) ◽  
pp. 601-615 ◽  
Author(s):  
Marianna Mészáros ◽  
Ingo Leya ◽  
Beda A Hofmann ◽  
Sönke Szidat
Keyword(s):  
High Precision ◽  
Gas Purification ◽  
Preliminary Results ◽  
Purification System ◽  
Interface System ◽  
University Of Bern ◽  
The University ◽  
Good Agreement ◽  
Terrestrial Age

AbstractHere, we introduce a new radiocarbon (14C) extraction line operating at the University of Bern, which was designed and built for the extraction of in situ 14C from meteorites. With this system, we achieved two important developments compared to other systems. First, using the MICADAS gas-interface system, 14C can directly be measured from the collected CO2 gas, i.e., without graphitization of the sample. Second, meteorite sample masses as low as ~0.05 g can be used for high precision and reproducibility. Prior to extraction in an oxygen atmosphere held at a pressure of ~20–30 mbar in an iridium crucible at 1600°C for 40 min, samples were preheated for 1 h in a constant oxygen flow at 500°C and continuous pumping. Gas purification followed the method described previously (e.g., Hippe et al. 2009). While the blank levels for preheated samples are low (<2×104 14C atoms), the blanks for non-preheated samples are high, therefore those results cannot be used. We also report preliminary results for the L-chondrite JaH 073. The terrestrial age of 17.7±0.4 ka is in good agreement with previous results for the same sample of this meteorite, confirming that the extraction line, the gas purification system, and the AMS measurements are all reliable.

RADIOCARBON IN MEXICO: FROM PROPORTIONAL COUNTERS TO AMS

Radiocarbon ◽  
2021 ◽  
pp. 1-7
Author(s):  
Corina Solís ◽  
Efraín Chávez ◽  
Arcadio Huerta ◽  
María Esther Ortiz ◽  
Alberto Alcántara ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
High Voltage ◽  
Accelerator Mass Spectrometry ◽  
Science And Technology ◽  
National Council ◽  
University Of Arizona ◽  
Technological Developments ◽  
High Voltage Engineering ◽  
The University

ABSTRACT Augusto Moreno is credited with establishing the first radiocarbon (14C) laboratory in Mexico in the 1950s, however, 14C measurement with the accelerator mass spectrometry (AMS) technique was not achieved in our country until 2003. Douglas Donahue from the University of Arizona, a pioneer in using AMS for 14C dating, participated in that experiment; then, the idea of establishing a 14C AMS laboratory evolved into a feasible project. This was finally reached in 2013, thanks to the technological developments in AMS and sample preparation with automated equipment, and the backing and support of the National Autonomous University of Mexico and the National Council for Science and Technology. The Mexican AMS Laboratory, LEMA, with a compact 1 MV system from High Voltage Engineering Europa, and its sample preparation laboratories with IonPlus automated graphitization equipment, is now a reality.

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