A new design of a Cs sputter ion source for accelerator mass spectrometry

1992 ◽  
Vol 63 (4) ◽  
pp. 2485-2487 ◽  
Author(s):  
Th. R. Niklaus ◽  
W. Baur ◽  
G. Bonani ◽  
H.‐A. Synal ◽  
W. Wölfli ◽  
...  
1998 ◽  
Vol 69 (3) ◽  
pp. 1353-1358 ◽  
Author(s):  
S. H. Sie ◽  
T. R. Niklaus ◽  
G. F. Suter ◽  
F. Bruhn

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 711-716 ◽  
Author(s):  
Christopher Bronk Ramsey ◽  
R. E. M. Hedges

In 14C tracer studies, and when looking for modern contamination in archaeological samples, it is often necessary to measure the 14C concentration of individual chemical fractions. Gas chromatography (GC) is one method that is frequently used for separation of chemical fractions. The gas ion source at the Oxford Radiocarbon Accelerator Unit for accelerator mass spectrometry (AMS) provides the opportunity to measure fractions from a GC instrument directly. Although the first investigations are likely to be 14C tracer studies, such a GC-AMS system could find much wider application. We present results from a pilot study of the peak sensitivity, baseline stability and crosstalk of the accelerator system used in this way. We also discuss the practical considerations in developing a GC-AMS instrument for routine use.


2012 ◽  
Vol 83 (2) ◽  
pp. 02B304 ◽  
Author(s):  
K. F. von Reden ◽  
M. L. Roberts ◽  
J. R. Burton ◽  
S. R. Beaupré

2007 ◽  
Author(s):  
Karl von Reden ◽  
Mark Roberts ◽  
Baoxi Han ◽  
Robert Schneider ◽  
John Wills

1998 ◽  
Vol 69 (2) ◽  
pp. 1188-1190 ◽  
Author(s):  
Per Persson ◽  
Kim Freimann ◽  
Ragnar Hellborg ◽  
Kjell Håkansson ◽  
Göran Skog ◽  
...  

The first significant experiment using the technique of accelerator mass spectrometry (AMS) was reported by Alvarez & Cornog in 1939. It was widely thought at the time that tritium , and not 3 He, was stable, and with that in m ind Rutherford had asked Aston to search for hydrogen of mass three in a specially prepared water sample. The result was negative and Rutherford reported this in the last paper he wrote, which was published in Nature a few months before his death in 1937. Alvarez realized that if 3 He, and not tritium , were stable then it should be present in ordinary helium, presumably at a low abundance level. He therefore fed helium into the ion source of the Berkeley 60 inch cyclotron and soon demonstrated the existence of a 24 MeV beam corresponding to mass three and charge two, a unique combination. This identification was confirmed by a measurement of the range of the accelerated particles. Subsequently, Alvarez & Cornog showed that the abundance of 3 He in atmospheric helium was about ten times greater than in well helium, although their absolute abundances were rather lower than the currently accepted values.


Radiocarbon ◽  
2016 ◽  
Vol 58 (2) ◽  
pp. 419-435 ◽  
Author(s):  
C Welte ◽  
L Wacker ◽  
B Hattendorf ◽  
M Christl ◽  
J Koch ◽  
...  

AbstractConventional radiocarbon analysis of carbonate records with accelerator mass spectrometry (AMS) is time consuming and the achievable spatial resolution is limited, because individual samples have to be taken and need to be converted to graphite for the measurement. A new laser ablation (LA) in situ sampling technique for rapid online 14C analyses of carbonate records by AMS is presented. By focusing a 193-nm ArF excimer laser on carbonate samples, carbon dioxide is generated and can directly be introduced into the gas ion source of an AMS. A dedicated LA cell for AMS was constructed in a way that combines rapid gas exchange with the capacity to carry sample specimen with maximum dimensions of 15×2.5×1.5 cm3. With the presented setup, negative carbon ion currents up to 20 µA were achieved. A low 14C background of 0.011±0.002 F14C was observed on 14C-free marble and different standard and reference materials could be well reproduced within errors. The novel technique allows scanning carbonate samples continuously over several cm per hour with achievable measurement precisions of less than 1% for modern samples. This approach allows acquiring highly spatially resolved 14C records at a far higher rate than with any currently available method.


1992 ◽  
Vol 63 (4) ◽  
pp. 2469-2471 ◽  
Author(s):  
R. Höpfl ◽  
T. Bretschneider ◽  
A. Buchler ◽  
Y. Charasse ◽  
W. Ernst ◽  
...  

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