The AMS technique for radiocarbon dating accounts for a substantial number of the analysis
requests we receive each day. There can be considerable advantages to using the AMS
technique in many dating applications, making possible the extension of radiocarbon dating
into many new areas of research. AMS also permits applications in important situations
that cannot be dated by the Radiometric technique. BETA, through its International
Consortium of Accelerator Laboratories, has been providing routine AMS radiocarbon dating
services to the international scientific community since 1983 by reporting in excess of
30,000 AMS radiocarbon dating results. Each year we report in excess of 5,000 AMS results,
all delivered within 30 working days from receiving the sample material. Our consortium
allows us to routinely deliver AMS results within the same reliable 30 business day period
as our Radiometric laboratory. By recognizing the strength in multi-disciplinary
cooperation, we are able to provide a uniquely efficient, precise dating service.
International Consortium of Accelerator
Laboratories (ICAL)
ICAL is composed of BETA's chemistry and graphite
laboratories and six member accelerators. Beta performs all of the chemical steps
necessary to ensure the most appropriate radiocarbon date from the submitted material.
This includes sample assessment, chemical pretreatment, combustion or acid
decomposition to carbon dioxide and chemical synthesis to graphite. This graphite is put
into an individual target container, ready for AMS measurement by an ICAL member.
ICAL physicists are experts in
AMS radiocarbon measurements.
CAL AMS members are an elite group of physicists who were instrumental in the
development of AMS radiocarbon dating. They are foremost authorities in instrument tuning,
set-up and monitoring of AMS radiocarbon measurements. Analyses of BETA graphite samples
relieves ICAL members of the complex chemistry and quality control measures required for
the production of AMS quality graphite.
Systematic agreement between
your samples and the reference standards is guaranteed.
Your samples are included in a 'full wheel" of
graphite targets, including backgrounds, moderns and known-age standards prepared by BETA.
These additional materials undergo the same chemical pretreatments and graphite syntheses
as do your samples. This is indispensable for precision radiocarbon dating. They are
interspersed throughout the accelerator wheel to provide reference measurements for the
age calculations and verifications. Only with rare exception is it acceptable to analyze
unknowns which have been prepared separately from the reference standards.
Advantages to using AMS analysis.
It can be used to radiocarbon date one milligram of
carbon or less.
The small sample size needed for analysis may permit a
more selective sampling.
The small sample requirement often allows a stronger
pretreatment than would otherwise be possible.
The small sample taken often means that a portion of the
original material can be archived
Statistical error is better for older and smaller
samples.
Measurement is quasi-simultaneous between reference
standards
and unknowns.
Our delivery time is dependably the fastest in the world: 6 to
30 business days.
Results of AMS dating analysis
are reported within 30 business days for the Standard AMS Delivery Service and within 6-14
business days for the Advance AMS Delivery Service. These quoted delivery times are
independent of the quantity of samples sent. When your samples are received, we quote an
expected terminal delivery date in a correspondence, letting you know the samples arrived
safely. We dependably meet this deadline because of our access to multiple accelerators.
If one accelerator "goes down", samples are analyzed by one of the other ICAL
members.
We start the samples immediately and stay in close contact with ICAL
members.
BETA begins the chemical treatments immediately. At the same time, backgrounds, moderns
and known-age samples are also being processed. The ICAL members contact us in advance
with proposed run dates and then guarantee priority for the times promised. The complete
wheel of samples is sent to the accelerator by express mail ready for measurement. The run
takes place a day or two later and the results are reported back to us immediately. We
then calibrate to calendar years, apply isotopic ratio corrections (where needed) and
report the results to you. This is usually within two days.
Our AMS dates are systematic with more than 85,000 radiometric
resultswe've reported over the last 20 years.
More researchers are using a mix of both AMS and Radiometric dating in order to
properlyanswer the complex questions posed by their research. Our AMS radiocarbon dates
are systematically the same as any of the Radiometric results provided by BETA since 1979.
Inter-calibration between the ICAL and Radiometric laboratories is essential to this. In
addition to reference standards, we circulate "blind" known-age samples, which
were measured radiometrically at BETA, between the ICAL members to insure non-biased
results. Also, we have an unprecedented quality control program (of which we would be glad
to send you a copy). Furthermore, we participate in all international standard
measurements and use international conventions for our radiocarbon dating calculations.
We are always available to
answer your questions.
Please don't hesitate to call, fax or e-mail us. We have many years experience in all
aspects of radiocarbon dating; you're very welcome to take advantage of this expertise. mailto:info@radiocarbon.com
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