Be and Al AMS standardizations
AMS standardizations

This page provides a list of standardizations to which Be-10 and Al-26 measurements submitted to the online exposure age and erosion rate calculators can be referenced. A 'standardization' means the combination of a particular isotope ratio standard material and an assumed isotope ratio for that material. Each standardization described below is associated with a name that appears in the first column. This name must be entered exactly in the appropriate place in the online calculator input forms. Note that two pieces of information are critical here: the identity of the actual standard material, and the nominal isotope ratio that the material is assumed to have. In a number of cases, the same physical standard material has been used with different assumed isotope ratios.

The goal here is that users not have to renormalize their AMS measurements before submitting them to the online calculators. For all the standardizations listed below, there is a known conversion factor that can be used to convert measurements made using that standardization to be compatible with the online calculators. The calculators will do that conversion internally before calculating exposure ages or erosion rates.

Thus, users are NOT required to renormalize data to a particular standardization before submitting it to the calculator -- the idea is that the user lists the standardization that was used for a particular sample, and the correction is done internally in a consistent fashion.

For more information, see the list of changes in version 2.2.

If you are using a standard material/isotope ratio pair that is not listed here, and you would like it to be added, please contact me.

Be standardizations
Name (Enter this in the appropriate place on calculator input pages) Description 
07KNSTD
 Any of a dilution series derived from the so-called "ICN solution" by K. Nishiizumi and described in Nishiizumi et al, 2007 (NIM-B v. 258, p. 403), with the revised nominal isotope ratios listed in that publication and in the printed description of the standards available from K. Nishiizumi and dated May 29, 2007. Measurements made at LLNL-CAMS with these standards and nominal isotope ratios will list '07KNSTDX,' where 'X' is a number related to the isotope ratio of the standard. Be-10 measurements made at PRIME Lab after November 14, 2007 were referenced to this set of standards and nominal isotope ratios. This is the standard on which the internal constants and production rates in the online exposure age calculator are based, so measurements made against any other standard will be internally converted to be consistent with this standard. 
KNSTD
 This refers to the same standard material as above -- the dilution series derived from the ICN solution by K. Nishiizumi -- but with a different nominal isotope ratio that was assumed for these standards before the 2007 revision. Measurements made at LLNL-CAMS with this set of standards and isotope ratios will list 'KNSTDX' as the name of the standard. Measurements made at PRIME Lab between January 12, 2005 and November 14, 2007 were referenced to this set of standards and isotope ratios. 
NIST_Certified
 This refers to a standard produced by the National Institute of Standards and Technology (NIST), referred to as SRM4325, with the nominal isotope ratio stated on the certificate for this material (2.68 x 10^-11 for the solution as supplied by NIST). Measurements made at PRIME Lab prior to January 12, 2005 were referenced to this standard and isotope ratio. 
NIST_30000
 Several AMS labs (ANU and SUERC, to my knowledge) have at various times used the NIST SRM4325 standard material, but assumed an isotope ratio of 3.0 x 10^-11 rather than the NIST certified value. 
NIST_30200
 NIST SRM4325 standard material with an assumed isotope ratio of 3.02 x 10^11 rather than the NIST certified value. Only ANSTO as far as I know. 
NIST_30300
 Some data from Uppsala use the NIST SRM4325 standard material with an assumed isotope ratio of 3.03 x 10^-11 rather than the NIST certified value. 
NIST_30600
 The NIST SRM4325 standard material with an assumed isotope ratio of 3.06 x 10^-11 rather than the NIST certified value. SUERC and possibly others. 
NIST_27900
 NIST SRM4325 standard material with an assumed isotope ratio of 2.79 x 10^-11. This standardization is equivalent to 07KNSTD within rounding error, so users can enter either one. Aster/CEREGE. 
S555
 ETH-Zurich standard material "S555" with an assumed isotope ratio of 95.5 x 10^-12. See Kubik and Christl (2009). 
S2007
 ETH-Zurich standard material "S2007" with an assumed isotope ratio of 30.8 x 10^-12. See Kubik and Christl (2009). 
LLNL31000
 An internal LLNL-CAMS standard. Identified as such on CAMS data reports. 
LLNL10000
 An internal LLNL-CAMS standard. Identified as such on CAMS data reports. 
LLNL3000
 An internal LLNL-CAMS standard. Identified as such on CAMS data reports. 
LLNL1000
 An internal LLNL-CAMS standard. Identified as such on CAMS data reports. 
LLNL300
 An internal LLNL-CAMS standard. Identified as such on CAMS data reports.
Al standardizations
Name (Enter this in the appropriate place on calculator input pages) Description 
KNSTD
 Any of a dilution series described in Nishiizumi, 2004 (NIM-B, v. 223-224, p. 388), with the nominal isotope ratios described in this publication. Measurements made at LLNL-CAMS with this standard will list 'KNSTDX,' where 'X' is a number related to the isotope ratio of the standard. This is the standard on which the internal constants and production rates in the online exposure age calculator are based. 
ZAL94
 ETH-Zurich standard material "ZAL94" with an assumed isotope ratio of 526 x 10^-12. The University of Cologne "AL09" standard material with an assumed isotope ratio of 1190 x 10^-12 is also consistent with this standardization. See Kubik and Christl (2009). 
ASTER
 Internal standard used at ASTER with an assumed isotope ratio of Al-26/Al-27 = 7.401 x 10^-12.