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.

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 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.

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.

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.

Super Sims for Ultrasensitive Impurity Analysis

1986 ◽  
Vol 69 ◽  
Author(s):  
J. M. Anthony ◽  
D. J. Donahue ◽  
A. J. T. Jull
Keyword(s):  
Mass Spectrometer ◽  
Ion Source ◽  
Particle Accelerator ◽  
Particle Identification ◽  
Radioactive Isotopes ◽  
Tandem Accelerator ◽  
Accelerator Mass Spectrometer ◽  
Source Contamination ◽  
Stable Elements ◽  
Current Detection

AbstractThe technique of accelerator mass spectrometry has been used extensively in recent years as a method for detecting low levels (< 1 part per trillion atomic) of radioactive isotopes in solid materials. The technique consists of a Secondary Ion Mass Spectrometer (SIMS) system in which the conventional mass spectrometer has been replaced by a particle accelerator. We have applied this method to the study of stable elements, primarily semiconductor dopants, using the Univ. of Arizona tandem accelerator mass spectrometer. The use of tandem accelerators allows molecular interferences to be removed due to dissociation of the molecules. Particle energies of several MeV are produced, and energy spectroscopy removes the background due to scattered particles, detector noise, etc. to provide positive particle identification. The current detection limits (-10 parts per billion atomic) are primarily due to ion source contamination and their origin is discussed. Removal of this contamination will allow parts per trillion level detection of stable elements.

An Electrostatic Tandem Accelerator for an Accelerator Mass Spectrometer

2018 ◽  
Vol 61 (1) ◽  
pp. 79-84 ◽  
Author(s):  
S. A. Rastigeev ◽  
V. V. Parkhomchuk ◽  
V. F. Klyuev
Keyword(s):  
Mass Spectrometer ◽  
Tandem Accelerator ◽  
Accelerator Mass Spectrometer
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