The preparation of precisely defined lithium isotope mixtures

Pauwels, J.; Lauer, Karl; Duigou, Y. Le; Bilèvre, P.J. De; Debus, G.H.

doi:10.1016/s0003-2670(00)89209-0

Cited by 10 publications

(4 citation statements)

References 2 publications

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“…This compound is then calibrated using synthetic mixtures containing varying isotope abundance, achieved by gravimetrically mixing calculated proportions of highly enriched isotopes of the element. Then, for a given TIMS methodology, the mass discrimination correction factor K is calculated using the iterative approach. − In the 1970s, the National Bureau of Standards (NBS) certified isotopic standards using this method with state-of-the-art instruments available at that period . However, advancements in instrumentation now yield within-run precision lower than certified uncertainties.…”

Section: Introductionmentioning

confidence: 99%

High-Precision Measurement of the ²³⁸Pu/²³⁹Pu Isotope Ratio by TIMS

Goswami,

Bhushan,

Jaison

2024

J. Am. Soc. Mass Spectrom.

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With an aim to improve the precision of isotopic standards of special nuclear materials like uranium and plutonium, National Bureau of Standards (NBS) undertook the recertification of isotopic standards prepared between 1960 and 1970. In a recent initiative, Lawrence Livermore National Laboratory (LLNL) in collaboration with New Brunswick Laboratory Program Office (NBL PO) undertaken efforts to recertify SRM 946, SRM 947, and SRM 948. The primary goal of this drive is to lower the uncertainties associated with the isotopic compositions of plutonium standards. The drive is also aims to minimize the uncertainty associated with measurement of the 238 Pu content from 2% to ∼0.3%. In this connection, our laboratory at the Fuel Chemistry Division, Bhabha Atomic Research Centre, proposes a novel indicator "minima in the (R MO 254/(i + 16) )/(R M 238/i ) curve" (where i = m/z 233 or 235 amu), which is the ratio of the isotope ratio of metal oxides ( 238 M 16 O/ i M 16 O) to that of metal ions ( 238 M/ i M) of uranium in determining the accurate 238 Pu content by thermal ionization mass spectrometry. Various enriched uranium spikes have been employed to study the efficacy of the minima in the (R MO (254)/(i + 16) )/(R M 238/i ) curve. With the combination of monitoring the minima in the (R MO (254)/(i + 16))/(R M 238/i ) curve and the application of the 233 U spike (with an isotope abundance of 238 U ∼ 0.05%), an external precision of 0.2% has been achieved in the determination of the 238 Pu/ 239 Pu isotope ratio for isotopic standard SRM 947.

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Section: Introductionmentioning

confidence: 99%

High-Precision Measurement of the ²³⁸Pu/²³⁹Pu Isotope Ratio by TIMS

Goswami,

Bhushan,

Jaison

2024

J. Am. Soc. Mass Spectrom.

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“…Synthetic mixtures of pure enriched isotopes for system calibration is an established technique for characterization of reference materials and for determination of the accurate atomic mass of an element. [1][2][3][4][5][6][7][8][9][10][11] A system calibration approach was used during the development of NBS standards such as boron isotopic standard SRM-951 where Na 2 BO 2 + was monitored. 5,6 The ions were formed from the reaction between Na 2 CO 3 and H 3 BO 3 with the B/Na mole ratio adjusted to one.…”

Section: Introductionmentioning

confidence: 99%

“…Synthetic mixtures having 10 B/ 11 B nominal ratios of 0.1, 0.25, 1, 2.3, 18 were prepared by gravimetric mixing of the calibrated enriched solutions in appropriate proportions. The assumption that the K factor determined using NIST SRM-951 is constant irrespective of the isotopic ratio [1][2][3][4][5][6][7][8][9][10][11] was made to arrive at the absolute ratio during the IDMS experiments. The calibration factors for the different isotopic blends obtained from the experimentally observed 10 B/ 11 B ratio for the different blends validated this assumption.…”

Section: Introductionmentioning

confidence: 99%

The preparation and use of synthetic isotope mixtures for testing the accuracy of the PTIMS method for 10B/11B isotope ratio determination using boron mannitol complex and NaCl for the formation of Na2BO2+

Rao

Parab

2012

Anal. Methods

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“…4 The calibration was carried out against mixtures prepared by Pauwels et al 5 and measured by Michiels and De Biévre. 6 These two materials are based on the same Li 2 CO 3 base material.…”

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confidence: 99%