scholarly journals Results of Tests and Measurements from the Nsf Regional Accelerator Facility for Radioisotope Dating

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 719-728 ◽  
Author(s):  
D J Donahue ◽  
T H Zabel ◽  
A J T Jull ◽  
P E Damon ◽  
K H Purser
Keyword(s):  
Mass Spectrometer ◽  
Tree Rings ◽  
Tandem Accelerator ◽  
Accelerator Facility ◽  
Tests And Measurements ◽  
University Of Arizona ◽  
Accelerator Mass Spectrometer ◽  
The University

Tests of performance of the tandem accelerator mass spectrometer at the NSF Regional Facility at the University of Arizona are discussed. Results of measurements on some tree rings and on some archaeologic samples are presented.

scholarly journals Study of Bone Radiocarbon Dating Accuracy at the University of Arizona NSF Accelerator Facility for Radioisotope Analysis

Radiocarbon ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 24-44 ◽  
Author(s):  
Thomas W Stafford ◽  
A J T Jull ◽  
Klaus Brendel ◽  
Raymond C Duhamel ◽  
Douglas Donahue
Keyword(s):  
Radiocarbon Dating ◽  
Fossil Bone ◽  
Accelerator Facility ◽  
University Of Arizona ◽  
Accelerator Mass Spectrometer ◽  
Calcified Tissue ◽  
The University ◽  
Original Organic Matter ◽  
Age Determinations ◽  
The Ideal

Bone would seem to be an ideal material for14C dating because this calcified tissue contains 20 weight per cent protein. Fossil bone, however, can lose most of its original organic matter and frequently contains contaminants having different14C ages. Numerous14C dates on bone have been available to archaeologists and geologists but many age determinations have been inaccurate despite over 30 years of research in the field following the first14C age determinations on bone (Arnold & Libby, 1951). This situation remained unchanged until simple pretreatments were abandoned and more bone-specific fractions were isolated. The ideal solution is to use accelerator mass spectrometer14C dating, which facilitates the use of milligram-sized amounts of highly purified compounds—an approach impossible to pursue using conventional14C decay-counting methods.

scholarly journals 14C AMS at Suerc: Improving QA Data with the 5MV Tandem and 250KV SSAMS

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 263-271 ◽  
Author(s):  
P Naysmith ◽  
G T Cook ◽  
S P H T Freeman ◽  
E M Scott ◽  
R Anderson ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Sample Preparation ◽  
Mass Spectrometer ◽  
Random Access ◽  
Capacity Measurement ◽  
Tandem Accelerator ◽  
Standard Data ◽  
Accelerator Mass Spectrometer ◽  
On Line ◽  
Automated Data Acquisition

In 2003, a National Electrostatics Corporation (NEC) 5MV tandem accelerator mass spectrometer was installed at SUERC, providing the radiocarbon laboratory with 14C measurements to 4–5‰ repeatability. In 2007, a 250kV single-stage accelerator mass spectrometer (SSAMS) was added to provide additional 14C capability and is now the preferred system for 14C analysis. Changes to the technology and to our operations are evident in our copious quality assurance data: typically, we now use the 134-position MC-SNICS source, which is filled to capacity. Measurement of standards shows that spectrometer running without the complication of on-line δ13C evaluation is a good operational compromise. Currently, 3‰ 14C/13C measurements are routinely achieved for samples up to nearly 3 half-lives old by consistent sample preparation and an automated data acquisition algorithm with sample random access for measurement repeats. Background and known-age standard data are presented for the period 2003–2008 for the 5MV system and 2007–2008 for the SSAMS, to demonstrate the improvements in data quality.

scholarly journals Timothy W Linick October 29, 1946–June 4, 1989

Radiocarbon ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. iii-iii
Author(s):  
Ajt Jull ◽  
Hans E Suess
Keyword(s):  
Tree Ring ◽  
Time Scale ◽  
Accelerator Facility ◽  
Radiocarbon Dates ◽  
University Of Arizona ◽  
The University

Timothy Weiler Linick died on June 4th, 1989. He was a dedicated researcher, and an important part of the NSF Accelerator Facility for Radioisotope Analysis at the University of Arizona. He will be remembered for his care and attention to details, especially in the calculation and reporting of radiocarbon dates. He made important contributions to the fields of oceanography and tree-ring calibration of the 14C time scale.

scholarly journals A High Throughput 14C Accelerator Mass Spectrometer

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 458-467 ◽  
Author(s):  
Kenneth H. Purser
Keyword(s):  
Mass Spectrometer ◽  
Unique Feature ◽  
Isotopic Ratios ◽  
Tandem Accelerator ◽  
Ocean Sciences ◽  
Accelerator Mass Spectrometer ◽  
Recent Sample ◽  
Present Design ◽  
On Line ◽  
Differential Transmission

I present design details of a tandem accelerator mass spectrometer, which has been installed at the National Ocean Sciences AMS Facility at Woods Hole, Massachusetts, to provide precision 14C/13C/12C isotopic ratios for sub-milligram-size samples of graphite with throughputs of >4000 samples per year. A unique feature is the capability for simultaneous measurement of all three isotopes after acceleration, to avoid differential transmission effects and to allow on-line fractionation corrections and diagnosis of instrument health. Using filamentous graphite fabricated from a recent sample, we have established the counting rate of 14C ions at between 60–120 s–1.

scholarly journals Operation of the NSF-Arizona Accelerator Facility for Radioisotope Analysis and Results from Selected Collaborative Research Projects

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 522-533 ◽  
Author(s):  
T W Linick ◽  
A J T Jull ◽  
L J Toolin ◽  
D J Donahue
Keyword(s):  
Collaborative Research ◽  
Radiocarbon Dating ◽  
Research Projects ◽  
Tandem Accelerator ◽  
Accelerator Facility ◽  
Modern Material ◽  
Sea Floor ◽  
Peruvian Coast ◽  
Accelerator Mass Spectrometer ◽  
Activity Ratios

Radiocarbon dating at the Arizona accelerator facility has improved substantially in the last three years. Since starting to use graphite targets (see Jull et al, 1986), we have been able to obtain routinely a precision of ca ± 1% (ca 80 yr) for relatively modern material. Our routine technique of tuning and operating the tandem accelerator mass spectrometer (TAMS) and our method of calculating 14C results are discussed in detail. Data on activity ratios of oxalic acid-II/oxalic-I are presented. Examples of the wide variety of projects on which we have collaborated are given. Brief discussions of three such projects are presented for our colleagues who were unable to attend this conference: an Arizona Indian archaeologic project, a study of megafaunal extinctions, and a study of the growth of phosphorite nodules on the sea floor off the Peruvian coast.

Early Corn Remains from Tumamoc Hill, Southern Arizona

1986 ◽  
Vol 51 (3) ◽  
pp. 563-572 ◽  
Author(s):  
Paul R. Fish ◽  
Suzanne K. Fish ◽  
Austin Long ◽  
Charles Miksicek
Keyword(s):  
Mass Spectrometer ◽  
Sonoran Desert ◽  
Small Sample ◽  
Tandem Accelerator ◽  
Accelerator Mass Spectrometer

The tandem accelerator mass spectrometer provided critical dating of corn remains in Archaic levels of juxtaposed Archaic and Hohokam occupations on Tumamoc Hill in Tucson, Arizona. This new radiometric technology confirmed an Archaic placement suggested by stratigraphy and artifact distributions. The small sample of intact remains resembles other directly-dated early corn in the Southwest and reinforces an interpretation of preceramic cultivators in the Sonoran Desert.

Fossil packrat middens and the tandem accelerator mass spectrometer

Nature ◽  
1985 ◽  
Vol 317 (6038) ◽  
pp. 610-613 ◽  
Author(s):  
Thomas R. Van Devender ◽  
Paul S. Martin ◽  
Robert S. Thompson ◽  
Kenneth L. Cole ◽  
A. J. Timothy Jull ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Tandem Accelerator ◽  
Accelerator Mass Spectrometer

Application of Tandem Accelerator Mass-Spectrometer Dating to Late Pleistocene-Holocene Sediments of the East Antarctic Continental Shelf

1989 ◽  
Vol 31 (2) ◽  
pp. 277-287 ◽  
Author(s):  
E. W. Domack ◽  
A. J. T. Jull ◽  
J. B. Anderson ◽  
T. W. Linick ◽  
C. R. Williams
Keyword(s):  
Continental Shelf ◽  
Mass Spectrometer ◽  
Late Quaternary ◽  
Planktonic Foraminifera ◽  
Small Samples ◽  
Tandem Accelerator ◽  
Antarctic Continental Shelf ◽  
Accelerator Mass Spectrometer ◽  
Wilkes Land ◽  
History Of

AbstractGlacial recession from the Antarctic continental shelf is recorded by glacial-marine diamictons, sands, and overlying siliceous oozes. In order to clarify the chronology for this sequence, use was made of the University of Arizona tandem accelerator mass-spectrometer (TAMS) for 14C dating. Small samples of benthic and planktonic foraminifera were selectively removed from diamictons, graded sands, and surface sediments which were recovered from the Wilkes Land continental shelf and slope, East Antarctica. Organic carbon was also utilized as a source for TAMS dating of the siliceous oozes and muds. Uncorrected ages varied from 14,260 ± 140 to 3230 ± 200 yr B.P. Carbon fixed by phytoplankton and foraminifera is strongly influenced by old, glacial-derived CO2. Thus, reservoir corrections of up to 5500 yr are needed for the 14C dates. Iceberg turbation reworks foraminifera so that dates from resulting deposits (diamictons) are interpreted as maximum ages. The consistency of corrected ages from the shelf, along with the sedimentologic interpretation, suggests a rather recent recession, perhaps mid-Holocene for this portion of the East Antarctic ice sheet. Further application of the TAMS method should help clarify other problems concerning the late Quaternary glacial history of Antarctica.

Radiocarbon Dating and Intercomparison of Some Early Historical Radiocarbon Samples

Radiocarbon ◽  
2018 ◽  
Vol 60 (2) ◽  
pp. 535-548 ◽  
Author(s):  
A J T Jull ◽  
C L Pearson ◽  
R E Taylor ◽  
J R Southon ◽  
G M Santos ◽  
...  
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Radiocarbon Dating ◽  
University Of Arizona ◽  
Materials Used ◽  
The University ◽  
Good Agreement ◽  
Made In

AbstractWe performed a new series of measurements on samples that were part of early measurements on radiocarbon (14C) dating made in 1948–1949. Our results show generally good agreement to the data published in 1949–1951, despite vast changes in technology, with only two exceptions where there was a discrepancy in the original studies. Our new measurements give calibrated ages that overlap with the known ages. We dated several samples at four different laboratories, and so we were also able to make a small intercomparison at the same time. In addition, new measurements on samples from other Egyptian materials used by Libby and co-workers were made at UC Irvine. Samples of tree rings used in the original studies (from Broken Flute Cave and Centennial Stump) were obtained from the University of Arizona Laboratory of Tree-Ring Research archive and remeasured. New data were compared to the original studies and other records.

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